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Communication

Low-Dose Dimethyl Sulfoxide (DMSO) Suppresses Androgen Receptor (AR) and Its Splice Variant AR-V7 in Castration-Resistant Prostate Cancer (CRPC) Cells

by
Namrata Khurana
1,2,
Hogyoung Kim
1,
Talal Khan
3,
Shohreh Kahhal
3,
Amar Bukvic
3,
Asim B. Abdel-Mageed
1,
Debasis Mondal
2,3,* and
Suresh C. Sikka
1,*
1
Department of Urology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
2
Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
3
Department of Biomedical Sciences, Lincoln Memorial University—DeBusk College of Osteopathic Medicine, 9737 Cogdill Road, Knoxville, TN 37932, USA
*
Authors to whom correspondence should be addressed.
Therapeutics 2025, 2(3), 15; https://doi.org/10.3390/therapeutics2030015
Submission received: 6 March 2025 / Revised: 13 June 2025 / Accepted: 24 August 2025 / Published: 27 August 2025
Browse Figures
Versions Notes

Abstract

Background: The outgrowth of castration-resistant prostate cancer (CRPC) dictates patient morbidity and mortality. Recurrence of prostate cancer (PC) following androgen-deprivation therapy (ADT) often occurs due to constitutively active androgen receptor (AR) splice variants (AR-Vs), primarily AR-V7. Therefore, safe and effective therapies enabling the suppression of both full-length AR (AR-FL) and AR-Vs are urgently needed. The natural compound dimethyl sulfoxide (DMSO) has negligible cytotoxicity at concentrations below 5% and has anticancer potential. DMSO has been broadly used in biomedical research as a solvent for pharmaceuticals, as a cryoprotectant for cells, and as a topical treatment to suppress pain and inflammation. We investigated the effect of low-dose DMSO on AR expression, cell viability, and metastatic ability in PC cell lines expressing both AR-FL and AR-V7 (e.g., 22Rv1) and those expressing only AR-FL (e.g., C4-2B). Methods: MTT cell viability assays were performed to measure DMSO-induced cytotoxicity. Wound-healing assays were conducted to monitor the effect of DMSO on the migratory phenotype of cancer cells. Western blot analyses were performed to study the efficacy of DMSO in suppressing the protein levels of AR-FL and AR-V7, and expression of heterogeneous nuclear ribonucleoprotein H1 (hnRNPH1) was measured as a possible mechanism. Results: At concentrations of 0.1–1% (v/v), DMSO treatment showed minimal cytotoxicity, whereas the highest concentration used (2.5%) showed approximately 20% cytotoxicity at 96 h. Interestingly, however, DMSO treatment at concentrations of 1.0 and 2.5% significantly inhibited the migration of PC cells. Treatment with DMSO led to a dose-dependent inhibition of both AR-FL and AR-V7. Notably, in 22Rv1 cells, DMSO potently downregulated the expression of hnRNPH1, a splicing factor often associated with AR expression and signaling. Conclusions: Our findings suggest that low concentrations of DMSO may have potential as an effective anticancer agent, both at the initial and later stages when PC cells become castration resistant.

1. Introduction

Prostate cancer (PC) remains a major cause of cancer-related deaths in elderly men in the United States [1]. Despite the initial efficacy of androgen-deprivation therapy (ADT), PC eventually progresses to castration-resistant prostate cancer (CRPC) [2]. Even in the absence of androgens, the progression of CRPC is associated with constant androgen receptor (AR) signaling [3,4,5,6,7]. Several mechanisms contribute to persistent AR signaling in CRPC cells. These include amplification of the AR gene, activation of AR in the absence of ligand (androgens) through cytokine- or kinase-mediated signaling pathways, intracrine or intratumoral synthesis of androgens, increased expression of AR coactivators, and, most notably, the presence of constitutively active AR splice variants (AR-Vs) [8,9]. Despite lacking the C-terminal ligand-binding domain, AR-Vs can transcriptionally activate AR target genes because they maintain the transactivating N-terminal domain [8,9,10].
AR-V7 (also known as AR3) is the most important AR-V that encodes a functional protein associated with CRPC recurrence [11,12,13,14,15,16,17,18,19]. Elevated levels of AR-V7 have been detected in tumor samples [18] and circulating tumor cells [13], especially after the development of CRPC. Also, overexpression of AR-V7 is associated with resistance to second-generation antiandrogens, such as enzalutamide and abiraterone acetate [20,21]. The AR-FL protein also plays a crucial role in dimerizing with AR-V7 and transactivating AR-regulated genes [22]. Thus, there is an urgent need for therapeutic strategies that can effectively eliminate the constitutive tumor-stimulating signaling associated with AR-FL and AR-V7 in CRPC cells.
We have previously shown that the plant-derived organosulfur compound, sulforaphane (SFN), can suppress full-length AR (AR-FL) and AR-V7 expression in CRPC cells [23,24]. However, SFN is yet to be clinically approved due to its low bioavailability in vivo. Here, we aimed to investigate the anticancer effect of another plant-derived organosulfur compound, dimethyl sulfoxide (DMSO), with a similar ‘sulfone’ group (Figure 1).
DMSO is an organic molecule with a unique structure consisting of one hydrophilic sulfoxide and two hydrophobic methyl groups [25]. This makes DMSO both water- and organic-media soluble. In the laboratory, DMSO is routinely used as a solvent for water-insoluble chemicals, both as a drug delivery enhancer [26] and as a cryoprotectant for inhibiting cell damage during freezing and thawing [27,28]. DMSO originates from lignin, a substance found in wood, and is therefore easily available and inexpensive [29]. Apart from its ability to dissolve huge sets of polar and nonpolar small molecules, DMSO has been identified for its exceptional property of transporting small molecules through several biological barriers, such as the skin and mucosa [30]. Therefore, clinically safe concentrations of DMSO may be easily translated into a novel anticancer treatment approach.
Even though the toxicity of high-dose DMSO has been reported previously [31,32,33], it is considered safe at low doses [34,35]. Interestingly, intravesical administration of concentrations as high as 50% DMSO (brand name Rimso-50), either alone or with other therapeutic agents, has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of interstitial cystitis/bladder pain syndrome [36]. DMSO exhibits muscle-relaxing, anti-inflammatory, analgesic, and bacteriostatic properties and facilitates the transfer of co-administered therapeutic agents into the bladder muscle across the urothelium [37,38,39]. Interestingly, DMSO has been investigated for its in vitro anticancer effect in various cancer cell lines, such as PC [40,41], breast cancer [42,43], lung cancer [43], skin cancer [44,45], colon cancer [46], and biliary cancer [47]. However, although the anticancer efficacy of DMSO has been tested on multiple PC cells, its efficiency in inhibiting the expression of both AR-FL and AR-V7 in CRPC cell lines has not been previously investigated.

2. Materials and Methods

2.1. Cell Culture

The C4-2B cell line, which is an androgen-independent PC cell line and expresses only the AR-FL, was obtained from the laboratory of Dr. Leland Chung at Cedars-Sinai Medical Center (Los Angeles, CA, USA) [48]. The 22Rv1 cell line, which is also an androgen-independent PC cell line and expresses both AR-FL and the splice variant AR-V7, was procured from the American Type Culture Collection (ATCC; Rockville, MD, USA). Both cell lines were cultured in RPMI-1640 medium (Roswell Park Memorial Institute; Buffalo, NY, USA) supplemented with 10% fetal bovine serum (FBS; Atlanta Biologicals; Lawrenceville, GA, USA) and 1% antibiotic–antimycotic solution (Thermo Scientific; Waltham, MA, USA). Cultures were maintained at 37 °C in a humidified atmosphere containing 5% CO2. For experiments requiring androgen deprivation, cells were transitioned to phenol red-free RPMI medium supplemented with 10% charcoal-stripped FBS (CS-FBS; Atlanta Biologicals) following serum starvation.

2.2. Reagents

DMSO and the tetrazolium dye MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] were purchased from Sigma-Aldrich (St. Louis, MO, USA). Primary antibodies used in this study included rabbit polyclonal antiandrogen receptor (AR, N-20; sc-816) and anti-glyceraldehyde-3-phosphate dehydrogenase (GAPDH; sc-47724), both obtained from Santa Cruz Biotechnology (Santa Cruz, CA, USA). The antibody against heterogeneous nuclear ribonucleoprotein H1 (hnRNPH1) was obtained from One World Lab (San Diego, CA, USA). Horseradish peroxidase (HRP)-conjugated goat anti-rabbit (A0545) and goat anti-mouse (A9044) secondary antibodies were procured from Sigma-Aldrich.

2.3. MTT Assay

Following DMSO treatment in androgen-deprived (CS-FBS) conditions, PC cell viability was assessed using the MTT assay. Approximately 5000 cells per well were seeded into 96-well plates and allowed to adhere, then synchronized overnight in serum-free medium prior to DMSO treatment (0.5–2.5% v/v). After 96 h of drug exposure, MTT reagent (5 mg/mL) was added to each well and incubated for 3–4 h at 37 °C to allow for formazan crystal formation. The resulting crystals were solubilized with 100% DMSO, and absorbance was measured at 540 nm using a µQuant spectrophotometric plate reader (BioTek; Seattle, WA, USA) to quantify cell viability and growth relative to untreated controls.

2.4. Western Blot Analysis

Following DMSO treatment, whole cell lysates were prepared using RIPA buffer (Santa Cruz Biotechnology). Protein concentration was determined using the bicinchoninic acid (BCA) assay (Thermo Fisher Scientific; Rockford, IL, USA). Equal amounts of protein (10 µg per sample) were separated on 10% SDS-PAGE gels and subsequently transferred to nitrocellulose membranes using a semi-dry blotting method. Membranes were blocked with 5% casein in Tris-buffered saline containing 0.1% Tween-20 (TBS-T) and incubated overnight at 4 °C with primary antibodies targeting AR (1:500), hnRNPH1 (1:1000), and GAPDH (1:3000). After thorough washing, membranes were incubated for 1 h at room temperature with the appropriate horseradish peroxidase (HRP)-conjugated secondary antibodies (1:2000). Protein bands were visualized using the SuperSignal West Femto substrate (Thermo Fisher Scientific), and images were acquired using the ImageQuant LAS 500 scanner (GE Healthcare; Princeton, NJ, USA). Densitometric analysis was performed using ImageJ 1.52v (NIH; Bethesda, MD, USA), and expression levels of AR (both AR-FL and AR-V7) and hnRNPH1 were normalized to GAPDH to calculate fold changes.

2.5. Wound-Healing Assay

To evaluate the migratory capacity of PC cells following treatment, a wound-healing assay was conducted as described previously [49]. Cells were seeded in 6-well plates at a density of 1 × 106 cells per well and cultured until a uniform monolayer was formed. A straight-line scratch was made across the cell layer using a sterile 200 µL pipette tip to create a wound. Detached cells were removed by rinsing with phosphate-buffered saline (PBS), and phase-contrast images of the wound area were captured at 0 h using a Leica microscope (10× magnification; Leica Microsystems, Buffalo Grove, IL, USA). After 72 h of drug treatment, the same regions were imaged again to assess cell migration. Wound closure was quantified by measuring the distance between opposing wound edges at 4–5 randomly selected positions.

2.6. Statistical Analysis

All statistical analyses were performed using GraphPad Prism 10.4.1 (GraphPad Software, La Jolla, CA, USA). Comparisons between groups were made using either paired or unpaired two-tailed t-tests, as appropriate. Data are presented as the mean ± standard error of the mean (SEM). A p-value of less than 0.05 was considered statistically significant.

3. Results

3.1. Exposure to Low Concentrations of DMSO Has Minimal Effect on Cancer Cell Viability

An MTT cell viability assay was used to determine the antiproliferative effect of DMSO in two CRPC cell lines, 22Rv1 and C4-2B. The cell viability data at 96 h showed that 0.1–1% DMSO had no detectable antiproliferative effect on the 22Rv1 and C4-2B cells (Figure 2). Even at a 2.5% dose, DMSO showed only a 20% decline in viable cell numbers in both cell line models. Therefore, in the following sections, further studies on the molecular effects on AR and hnRNPH1 expression and cancer cell migration were conducted at these subtoxic doses of DMSO.

3.2. Low-Dose DMSO Rapidly Decreases AR (AR-FL and AR-V7) Protein Levels in PC Cells

For these studies, the 22Rv1 cells expressing both AR-FL and AR-V7 were treated with increasing concentrations of DMSO (0.1–2.5% v/v), and the protein levels of AR were detected at 24 h. An immunoblot analysis showed that exposure to DMSO (2.5%) caused a significant reduction in the protein levels of both AR-FL and AR-V7 (Figure 3A,B). Interestingly, exposure to DMSO had a more robust suppressive effect on AR-V7 levels compared to AR-FL levels. The suppressive effect on AR-V7 was observed with DMSO at a concentration as low as 0.5%, whereas the suppressive effect on AR-FL was evident at 2.5%. Most importantly, AR-V7 protein levels were almost undetectable with 2.5% DMSO. Next, we aimed to determine the AR suppressive effect of DMSO in C4-2B cells, which express only AR-FL. Significant AR-FL inhibition by DMSO was observed at a concentration of 1% and higher. There was a marked reduction in AR-FL protein levels with 2.5% DMSO treatment (Figure 3C,D). However, no significant changes in GAPDH expression were evident in either 22Rv1 or C4-2B cell lines.

3.3. Exposure to Subtoxic DMSO Doses Causes Significant Suppression of C4-2B Cell Migration

Following exposure to cytotoxic therapies, aggressive drug-resistant cancer cells can evade immune surveillance and the action of therapeutic agents by rapidly migrating to sequestered tissue reservoirs. Studies suggest that cancer cells can undergo epithelial–mesenchymal transition (EMT), which is a hallmark of tumor metastasis. Increased metastatic ability of PC cells has been attributed to increased AR expression and signaling [2,7]. Our previous experiments clearly demonstrated that exposure to low concentrations of DMSO can rapidly suppress AR protein levels and thus may have suppressive effects on the migratory phenotype of these PC cells as well. Therefore, we performed wound-healing assays to determine the migration of PC cells following 72 h of exposure to low doses of DMSO. As depicted in Figure 4A,B, significant suppression in the migratory ability of C4-2B cells was documented even at DMSO concentrations of 1%, and exposure to 2.5% DMSO almost completely abrogated the migration of C4-2B cells. These results are clearly evident from the images of wound widths at 72 h and the bar graphs showing quantification of wound widths in control vs. treated cells.

3.4. DMSO Treatment Downregulates the Expression of hnRNPH1 in 22Rv1 Cells

In PC cell lines, the splicing factor hnRNPH1 has been shown to regulate both the transcription and activation of AR-FL and AR-V7 [50]. Therefore, we aimed to determine the effect of DMSO on the protein expression of hnRNPH1. Immunoblot analysis at 24 h revealed that DMSO treatment significantly downregulated the expression of hnRNPH1 in 22Rv1 cells (Figure 5). Interestingly, this suppressive effect was documented even at DMSO doses as low as 0.1%. These molecular findings imply a novel mechanism of action of low-dose DMSO in suppressing AR expression in aggressive PC cells.

4. Discussion

The recurrence of CRPC cells is contingent upon a continuous and persistent AR signaling following antiandrogen therapy [2]. Overexpression of AR-V7 has been largely responsible for the outgrowth of CRPC cells [11]. Also, the crosstalk of AR with several different molecular pathways can further lead to the activation of AR and thus facilitate tumor growth and metastasis [51,52]. Therefore, safe and effective therapies that can potently target both AR-FL and AR-V7 are critically needed [53]. DMSO has shown anticancer effects in various cancers [42,43,44,45,46,47], including PC [40,41,54]. In our current study, we observed that lower doses of DMSO do not exhibit significant cytotoxicity in 22Rv1 and C4-2B cells, and even at the highest concentration of 2.5% DMSO, cytotoxicity was approximately 20% at 96 h post-exposure. In addition, our unpublished studies showed that these low doses of DMSO were nontoxic to primary human mesenchymal stem cells as well. Therefore, we wanted to investigate whether these low doses of DMSO can effectively inhibit the expression of both AR-FL and AR-V7.
Subtoxic concentrations of DMSO showed a dose-dependent suppressive effect on AR expression in both PC cell lines. In 22Rv1 cells, expressing both AR-FL and AR-V7, DMSO had a more robust effect in inhibiting the expression of AR-V7 compared with AR-FL. This enhanced inhibitory effect on AR-V7 was observed at doses as low as 0.5%, and the AR-V7 level was virtually undetectable at 24 h exposure to 2.5% DMSO. Interestingly, however, the inhibitory effect of DMSO on AR-FL levels was only observed at a concentration of 2.5%. In C4-2B cells, expressing only AR-FL, the inhibitory effect was observed at 1% DMSO, with AR-FL expression abrogated at 2.5% DMSO. Although the molecular mechanism(s) linked to this AR-suppressive effect of DMSO are currently unknown, several past publications have suggested that even low-dose DMSO may alter cellular functions. Interestingly, one study demonstrated that 2.5% DMSO can alter the structural cooperativity and unfolding mechanism of bacterial NAD+ synthetase [55], suggesting DMSO’s possible role in regulating oxidative stress and redox signaling pathways.
Notably, DMSO (at 1% and 2.5% concentrations) also decreased the migration of C4-2B cells at 72 h. Since AR signaling is known to augment the aggressive behavior of PC cells, as characterized by higher tumor invasion, apoptotic resistance, and EMT, our findings suggest that clinically achievable and safe doses of DMSO may be able to suppress the metastatic properties of PC cells [56,57].
Indeed, DMSO has also been identified as an inducer of cell differentiation in embryonic stem cells [58] and cancer cell models [59], suggesting multiple mechanisms of DMSO action on cancer cells. DMSO has been shown to inhibit cell proliferation as well as glycosaminoglycan synthesis and secretion in rat prostate adenocarcinoma cells in culture [41]. Interestingly, these investigators observed that the cells that survived the initial exposure to 2.5% DMSO showed reversible indications of increased differentiation, such as decreased growth rate and saturation density. Since our findings show that even a single exposure to safe doses of DMSO can precipitate antiproliferative, antimetastatic, and AR-suppressive effects, it is likely that chronic exposure to low-dose DMSO may also have greater benefits, which need to be tested in the future.
The novel mechanisms via which low-dose DMSO, a small molecule organosulfur compound, can rapidly and potently downregulate both AR-FL and AR-V7 need to be more extensively studied at the molecular level. In our previously published studies using another organosulfur compound, SFN, we showed similar inhibitory effects on AR-FL expression in C4-2B cells [23] and on both AR-FL and AR-V7 expression in 22Rv1 cells [24]. Our molecular investigations also showed that SFN downregulated AR expression at both the mRNA and protein levels. In addition, exposure to SFN increased proteasomal activity and AR degradation, which was validated by using the proteasomal inhibitor MG132 [23,24]. The mechanism by which DMSO suppresses both AR-FL and AR-V7 in several PC cell lines may be similar to our published findings using SFN and may involve a multimodal action. We plan to perform these experiments in our future molecular mechanistic studies using low-dose DMSO. Interestingly, in addition to SFN, several other sulfur-containing compounds, including phenethyl isothiocyanate [60,61,62], n-acetyl cysteine [63], diallyl sulfides [64,65], and hydrogen sulfide [66], have shown anticancer effects in PC cells, and were found to function via the suppression of AR levels in CRPC cells. Hence, the mechanism(s) associated with this therapeutic effect of sulfur-containing compounds need to be thoroughly investigated.
Our immunoblot studies also documented that DMSO treatment potently downregulated the expression of hnRNPH1. Indeed, the suppressive effects of DMSO on hnRNPH1 protein levels were seen even at the lower DMSO concentrations used. One recent study on prostate tumor progression reported abnormal expression of both AR and hnRNPH1, along with the downregulation of microRNA 212 (miR-212) [50]. When miR-212 was ectopically overexpressed, these investigators demonstrated the downregulation of hnRNPH1 and decreased levels of both AR and AR-V7. Most notably, hnRNPH1 was also shown to physically interact with AR and steroid receptor coactivator-3 (SRC-3), facilitating the activation of androgen-regulated genes in both ligand-dependent and ligand-independent manner [50,51]. Furthermore, prostate tumorigenesis was inhibited in vivo, and PC cells became sensitive to bicalutamide treatment when hnRNPH1 was silenced using short-interfering RNAs (siRNA). These previous studies recognized the multiple actions of hnRNPH1 as a splicing factor, an oncogene, and a secondary AR coregulator, and suggested that targeted therapeutic inhibition of hnRNPH1 may lead to the disruption of the hnRNPH1–AR axis. Additionally, numerous other splicing regulatory proteins for AR, such as DDX23, NONO, PSF, and SF3B2 [67], may be associated with a potent suppression of AR-FL and AR-V7, and the effect of DMSO on these AR-regulatory splicing factors will need to be tested. In our current study, we demonstrated that the clinically tested concentrations of DMSO can significantly reduce the expression of hnRNPH1 and may be one of the underlying mechanisms by which DMSO suppresses both AR-FL and AR-V7.
Despite its multiple beneficial effects, the use of DMSO in clinical settings has been limited due to its possible adverse reactions [31,32,33]. Importantly, a 2019 systematic review on the adverse reactions of DMSO in humans included all 109 original studies with five or more participants [35]. This systematic review concluded that the adverse reactions to DMSO are often mild and transient (without the need for intervention) and do not qualify as serious adverse events. Gastrointestinal and skin reactions were the most reported adverse reactions to DMSO. Cardiovascular and respiratory adverse reactions were more common with intravenous administration of DMSO, whereas dermatological reactions occurred mostly with transdermal administration of DMSO. Thus, a correlation was observed between the dose of DMSO and the occurrence of adverse reactions, indicating that DMSO is likely safe when used in low doses. Notably, in another study [40], where the infusion of DMSO and sodium bicarbonate (pH buffer) was used to treat 18 patients with metastatic PC for palliative care and pain relief, no significant side effects were apparent. In another study by the same authors, a combination of DMSO–sodium bicarbonate infusion and S-adenosyl-L-methionine (SAM) oral supplementation was used as palliative pharmacotherapy in nine patients with advanced, nonresectable, biliary tract carcinomas [47], which resulted in a 6-month progression-free survival for all the patients. In both the above studies, the patients showed significant pain control as well as improvement in clinical symptoms, blood and biochemistry tests, and quality of life. Furthermore, no major side effects were reported. Therefore, the AR-suppressive effects of low-dose DMSO may be exploited as a novel treatment in patients with refractory PC to suppress CRPC outgrowth.
Similar to our findings using multiple PC cell lines, a number of past studies have demonstrated the in vitro anticancer effects of DMSO in multiple other cancers, such as breast cancer [42,43], lung cancer [43], skin cancer [44,45], and colon cancer [46]. DMSO was reported to inhibit the metabolic activity of melanoma cells [44]. DMSO at higher concentrations (up to 10%) was not shown to cause significant cell damage in colon tumor cells [46]. Additionally, DMSO has been reported as a potent oral radioprotective agent, providing radioprotection of hematopoietic stem and progenitor cells independent of apoptosis [68]. DMSO treatment dramatically increased drug metabolism activity in Huh7 hepatoma cells [69]. Also, as an adjuvant agent, DMSO enhanced the efficacy of co-administered drugs due to its penetration-enhancing capability [70]. DMSO treatment increased the efficacy of photodynamic therapy by enhancing penetration and production of photosensitizers (5-aminolevulinic acid-induced porphyrins) in basal cell carcinoma (BCC) [71]. The application of topical DMSO was also shown to improve the remission rate in BCC [72]. Enhanced skin penetration of finasteride-loaded DMSO liposomes has been reported for the treatment of androgenic alopecia, compared to conventional liposomes [73]. Past evidence has shown that DMSO can be safely used at low concentrations and may have anticancer effects due to its multimodal actions against aggressive tumor cells. These findings underscore the significance of our current findings, showing that low concentrations of DMSO (≤2.5%) can suppress AR protein levels in multiple CRPC cell lines and thus may suppress both their proliferative potential and metastatic abilities.

5. Conclusions

Our in vitro findings in two aggressive CRPC cell lines show that low-dose DMSO may have significant AR inhibitory effects and can decrease both cell growth and migration of these cells. Safe concentrations of DMSO may be used either alone or in conjunction with conventional anticancer therapy, both at the onset of PC when cells express only AR-FL and during the later stages when CRPC cells that express the constitutively active AR-V7 have emerged. Therefore, the clinical utility of low-dose DMSO and its repositioning as an agent against PC may be of great significance to the scientific and medical community.

Author Contributions

Conceptualization, N.K., D.M. and S.C.S.; Methodology, N.K., H.K., T.K., S.K. and A.B.; Software, N.K.; Validation, N.K., D.M. and S.C.S.; Formal analysis, N.K., D.M. and S.C.S.; Investigation, N.K., D.M. and S.C.S.; Resources, D.M. and S.C.S.; Data curation, N.K., D.M. and S.C.S.; Writing—N.K.; Writing—review and editing, N.K., D.M. and S.C.S.; Visualization, N.K., D.M. and S.C.S.; Supervision, D.M., A.B.A.-M. and S.C.S.; Project administration, D.M. and S.C.S.; Funding acquisition, D.M. and S.C.S. All authors have read and agreed to the published version of the manuscript.

Funding

This study was supported by research funds of Tulane University’s Department of Urology and Department of Pharmacology, awarded to S.C.S. and D.M.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data on search results, study selection, data collection, and quality assessment are available on request.

Acknowledgments

The authors wish to thank Scott Bailey, Department of Urology, Tulane University School of Medicine, for editing this manuscript.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 1. The clinically tested small molecule DMSO has a similar sulfone group as compared with the investigational anticancer phytochemical, sulforaphane.
Figure 1. The clinically tested small molecule DMSO has a similar sulfone group as compared with the investigational anticancer phytochemical, sulforaphane.
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Figure 2. Effect of DMSO on the cell viability of prostate cancer cells. 22Rv1 and C4-2B cells were treated with increasing concentrations of DMSO (0–2.5% v/v), and cell viability was determined at 96 h. The data (% of control) are expressed as the ± SEM of three independent experiments (n = 3) in both 22Rv1 and C4-2B cells. Significant differences between the groups are shown as * p < 0.05.
Figure 2. Effect of DMSO on the cell viability of prostate cancer cells. 22Rv1 and C4-2B cells were treated with increasing concentrations of DMSO (0–2.5% v/v), and cell viability was determined at 96 h. The data (% of control) are expressed as the ± SEM of three independent experiments (n = 3) in both 22Rv1 and C4-2B cells. Significant differences between the groups are shown as * p < 0.05.
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Figure 3. Effect of DMSO on AR levels in prostate cancer cells. 22Rv1 and C4-2B cells were treated with increasing concentrations of DMSO (0–2.5% v/v), and cell lysates were harvested at 24 h following treatment. Representative immunoblots of AR and GAPDH protein levels are shown for (A) 22Rv1 and (C) C4-2B cells. The normalized fold-change data are expressed as the ± SEM of three independent experiments (n = 3) in both (B) 22Rv1 and (D) C4-2B cells. Significant differences between groups are shown as * p < 0.05 and ** p < 0.005. Abbreviations: AR-FL, full-length androgen receptor; AR-V7, androgen receptor splice variant 7; GADPH, glyceraldehyde-3-phosphate dehydrogenase.
Figure 3. Effect of DMSO on AR levels in prostate cancer cells. 22Rv1 and C4-2B cells were treated with increasing concentrations of DMSO (0–2.5% v/v), and cell lysates were harvested at 24 h following treatment. Representative immunoblots of AR and GAPDH protein levels are shown for (A) 22Rv1 and (C) C4-2B cells. The normalized fold-change data are expressed as the ± SEM of three independent experiments (n = 3) in both (B) 22Rv1 and (D) C4-2B cells. Significant differences between groups are shown as * p < 0.05 and ** p < 0.005. Abbreviations: AR-FL, full-length androgen receptor; AR-V7, androgen receptor splice variant 7; GADPH, glyceraldehyde-3-phosphate dehydrogenase.
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Figure 4. Effect of DMSO on migration of prostate cancer cells. Cell migration was quantified by wound-healing assay. (A) A representative light microscope image of the wound at 0 and 72 h is shown for both untreated C4-2B cells and those treated with 1% and 2.5% DMSO. (B) Fold change in wound width is expressed as the mean ± SEM of two independent experiments (n = 2), and significant differences between groups are shown as p-values (* p < 0.05; ** p < 0.005).
Figure 4. Effect of DMSO on migration of prostate cancer cells. Cell migration was quantified by wound-healing assay. (A) A representative light microscope image of the wound at 0 and 72 h is shown for both untreated C4-2B cells and those treated with 1% and 2.5% DMSO. (B) Fold change in wound width is expressed as the mean ± SEM of two independent experiments (n = 2), and significant differences between groups are shown as p-values (* p < 0.05; ** p < 0.005).
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Figure 5. Effect of DMSO on HNRNPH1 levels in prostate cancer cells. 22Rv1 cells were treated with increasing concentrations of DMSO (0–2.5% v/v), and cell lysates were harvested 24 h after treatment. A representative immunoblot of hnRNPH1 and GAPDH protein levels is shown for 22Rv1 cells. The normalized densitometric values for hnRNPH1 are shown in the top panels. Abbreviations: hNRNPH1, heterogeneous nuclear ribonucleoprotein H1; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.
Figure 5. Effect of DMSO on HNRNPH1 levels in prostate cancer cells. 22Rv1 cells were treated with increasing concentrations of DMSO (0–2.5% v/v), and cell lysates were harvested 24 h after treatment. A representative immunoblot of hnRNPH1 and GAPDH protein levels is shown for 22Rv1 cells. The normalized densitometric values for hnRNPH1 are shown in the top panels. Abbreviations: hNRNPH1, heterogeneous nuclear ribonucleoprotein H1; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.
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MDPI and ACS Style

Khurana, N.; Kim, H.; Khan, T.; Kahhal, S.; Bukvic, A.; Abdel-Mageed, A.B.; Mondal, D.; Sikka, S.C. Low-Dose Dimethyl Sulfoxide (DMSO) Suppresses Androgen Receptor (AR) and Its Splice Variant AR-V7 in Castration-Resistant Prostate Cancer (CRPC) Cells. Therapeutics 2025, 2, 15. https://doi.org/10.3390/therapeutics2030015

AMA Style

Khurana N, Kim H, Khan T, Kahhal S, Bukvic A, Abdel-Mageed AB, Mondal D, Sikka SC. Low-Dose Dimethyl Sulfoxide (DMSO) Suppresses Androgen Receptor (AR) and Its Splice Variant AR-V7 in Castration-Resistant Prostate Cancer (CRPC) Cells. Therapeutics. 2025; 2(3):15. https://doi.org/10.3390/therapeutics2030015

Chicago/Turabian Style

Khurana, Namrata, Hogyoung Kim, Talal Khan, Shohreh Kahhal, Amar Bukvic, Asim B. Abdel-Mageed, Debasis Mondal, and Suresh C. Sikka. 2025. "Low-Dose Dimethyl Sulfoxide (DMSO) Suppresses Androgen Receptor (AR) and Its Splice Variant AR-V7 in Castration-Resistant Prostate Cancer (CRPC) Cells" Therapeutics 2, no. 3: 15. https://doi.org/10.3390/therapeutics2030015

APA Style

Khurana, N., Kim, H., Khan, T., Kahhal, S., Bukvic, A., Abdel-Mageed, A. B., Mondal, D., & Sikka, S. C. (2025). Low-Dose Dimethyl Sulfoxide (DMSO) Suppresses Androgen Receptor (AR) and Its Splice Variant AR-V7 in Castration-Resistant Prostate Cancer (CRPC) Cells. Therapeutics, 2(3), 15. https://doi.org/10.3390/therapeutics2030015

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