Search Results (407)

The use of radiosensitizers is a beneficial approach in cancer radiotherapy treatment. However, the enhancement of radiation effects on cancer cells by radiosensitizers involves several different mechanisms, reflecting the chemical nature of the radiosensitizer. G-quadruplex (G4) DNA ligands have emerged in recent years as a potential new class of radiosensitizers binding to specific DNA sequences. Recently, we have shown that the Re(I) tricarbonyl complex PDF-Pz-Re and its pyrazolyl-diamine chelator PDF-Pz, carrying a N-methylated pyridostatin (PDF) derivative, act as G4 binders of various G4-forming DNA and RNA sequences. As described in this contribution, these features prompted us to evaluate PDF-Pz-Re and PDF-Pz as radiosensitizers of prostate cancer PC3 cells submitted to concomitant treatment with Co-60 radiation. The compound RHPS4 was also tested, as this G4 ligand was previously shown to exhibit strong radiosensitizing properties in other cancer cell lines. The assessment of the resulting radiobiological effects, namely through clonogenic cell survival, DNA damage, and ROS production assays, showed that PDF-Pz-Re and PDF-Pz were able to radiosensitize PC3 cells despite being less active than RHPS4. Our results corroborate that G4 DNA ligands are a class of compounds with potential interest as radiosensitizers, deserving further studies to optimize their radiosensitization activity and elucidate the mechanisms of action. Full article

Objectives: To investigate the efficacy and underlying mechanisms of IBCar’s biological activity in breast cancer models, both in cell culture and in mice, and to compare its effects on cancer versus normal cells. Methods: The cytotoxicity of IBCar was evaluated using the MTS assay to assess metabolic activity and the clonogenic assay to determine reproductive integrity. The impact of IBCar on microtubule integrity, mitochondrial function, and multiple signaling pathways was analyzed using Western blotting, microarray analysis, and live cell imaging. The therapeutic effectiveness of orally administered IBCar was assessed in a transgenic mouse model of Luminal B breast cancer and in mice implanted with subcutaneous triple-negative breast cancer xenografts. Results: IBCar demonstrated potent cytotoxicity across a diverse panel of breast cancer cell lines, including those with mutant or wild-type TP53, and cell lines with short and long doubling times. Comparative analysis revealed distinct responses between normal and cancer cells, including differences in IBCar’s effects on the mitochondrial membrane potential, endoplasmic reticulum stress and activation of cell death pathways. In breast cancer cells, IBCar was cytotoxic at nanomolar concentrations, caused irreversible microtubule depolymerization leading to sustained mitochondrial dysfunction, endoplasmic reticulum stress, and induced apoptosis. In normal cells, protective mechanisms included reversible microtubule depolymerization and activation of pro-survival signaling via the caspase-8 and riptosome pathways. The therapeutic potential of IBCar was confirmed in mouse models of Luminal B and triple negative BC, where it exhibited strong antitumor activity without detectable toxicity. Conclusions: These findings collectively support IBCar as a promising, effective, and safe therapeutic candidate for breast cancer treatment. Full article

Colorectal cancer (CRC) remains a predominant cause of global cancer-related mortality, highlighting the pressing demand for innovative therapeutic strategies. Natural polysaccharides have emerged as promising candidates in cancer research due to their multifaceted anticancer mechanisms and tumor-suppressive potential across diverse malignancies. In this study, we enzymatically extracted a polysaccharide, named ERPP, from Ruditapes philippinarum and comprehensively evaluated its anti-colorectal cancer activity. We conducted in vitro assays, including CCK-8 proliferation, clonogenic survival, scratch wound healing, and Annexin V-FITC/PI apoptosis staining, and the results demonstrated that ERPP significantly inhibited HT-29 cell proliferation, suppressed colony formation, impaired migratory capacity, and induced apoptosis. JC-1 fluorescence assays provided further evidence of mitochondrial membrane potential (MMP) depolarization, as manifested by a substantial reduction in the red/green fluorescence ratio (from 10.87 to 0.35). These antitumor effects were further validated in vivo using a zebrafish HT-29 xenograft model. Furthermore, ERPP treatment significantly attenuated tumor angiogenesis and downregulated the expression of the vascular endothelial growth factor A (Vegfaa) gene in the zebrafish xenograft model. Mechanistic investigations revealed that ERPP primarily activated the mitochondrial apoptosis pathway. RT-qPCR analysis showed an upregulation of the pro-apoptotic gene Bax and a downregulation of the anti-apoptotic gene Bcl-2, leading to cytochrome c (CYCS) release and caspase-3 (CASP-3) activation. Additionally, ERPP exhibited potent antioxidant capacity, achieving an 80.2% hydroxyl radical scavenging rate at 4 mg/mL. ERPP also decreased reactive oxygen species (ROS) levels within the tumor cells, thereby augmenting anticancer efficacy through its antioxidant activity. Collectively, these findings provide mechanistic insights into the properties of ERPP, underscoring its potential as a functional food component or adjuvant therapy for colorectal cancer management. Full article

Background/Objectives: Alectinib, a second-generation tyrosine kinase inhibitor indicated for the treatment of non-small-cell lung cancer (NSCLC), exhibits suboptimal oral bioavailability, primarily attributable to its inherently low aqueous solubility and limited dissolution kinetics. This study aimed to enhance Alectinib’s solubility and therapeutic efficacy by formulating a G4-NH2-PAMAM dendrimer complex. Methods: The complex was prepared using the organic solvent evaporation method and characterized by DSC, FTIR, dynamic light scattering (DLS), and zeta potential measurements. A validated high-performance liquid chromatography (HPLC) method quantified the Alectinib. In vitro drug release studies compared free Alectinib with the G4-NH2-PAMAM dendrimer complex. Cytotoxicity against NSCLC cell line A549 was assessed using MTT assays, clonogenic assay, and scratch-wound assay. Xenograft effect was investigated in the H460 lung cell line. Pharmacokinetic parameters were evaluated in rats using LC–MS/MS. Results: Alectinib exhibited an encapsulation efficiency of 59 ± 5%. In vitro release studies demonstrated sustained drug release at pH 6.8 and faster degradation at pH 2.5. Anticancer activity in vitro showed comparable efficacy to free Alectinib, with 98% migration inhibition. In vivo tumor suppression studies revealed near-complete tumor regression (~100%) after 17 days of treatment, compared to 75% with free Alectinib. Pharmacokinetic analysis indicated enhanced absorption (shorter Tmax), prolonged systemic circulation (longer half-life), and higher bioavailability (increased AUC) for the dendrimer-complexed drug. Conclusions: These findings suggest that the G4-NH2-PAMAM dendrimer system significantly improves Alectinib’s pharmacokinetics and therapeutic potential, making it a promising approach for NSCLC treatment. Full article

Beyond its immunological role, colostrum has emerged as a promising, non-invasive source of bioactive factors, including mesenchymal stem/stromal cells (MSCs). This study represents the first attempt to isolate and characterize MSCs from equine colostrum (C-MSCs) to assess their potential use in veterinary regenerative medicine. Colostrum (n = 6) was collected from mares immediately after their delivery and centrifuged, and the recovered cells were cultured under standard conditions. The C-MSCs displayed plastic adherence and a heterogeneous morphology, including spindle-shaped and epithelial-like cells. The population doubling time (PDT) values varied among the samples, and four out of six showed rapid proliferation (<2 days). Colony-forming unit (CFU) assays confirmed their clonogenic potential, though significant inter-sample variability was observed (p < 0.05). Spheroid formation assays revealed differences in cell–cell adhesion: four out of six samples formed stable spheroids within four days. A migration assay showed significant variability (p < 0.05): one out of six achieved complete wound closure within 72 h, whereas five out of six reached ~30% at 96 h. All samples were positive for adipogenic, chondrogenic, and osteogenic differentiation as shown via staining. RT-PCR confirmed MSC marker expression, while hematopoietic markers were absent. MHC-I expression was weak in five out of six samples, whereas MHC-II was consistently negative. These findings support equine colostrum as a viable MSC source, though its variability requires further validation with larger samples. Additional research is needed to investigate C-MSCs’ immunomodulatory properties and therapeutic potential. Full article

Natural compounds remain a valuable source of anticancer agents due to their structural diversity and multi-targeted mechanisms of action. Roburic acid (RA), a tetracyclic triterpenoid, has been identified as a substance capable of inhibiting key NF-κB and MAPK signaling pathways through direct interaction with TNF-α, as well as preventing the production of inflammatory mediators and cancer progression. In this study, we evaluated the biological activity of RA against a panel of human cancer cell lines—DLD-1, HT-29, and HCT-116 (colorectal), PC-3 (prostate), and BxPC-3 (pancreatic)—as well as two non-malignant lines: WI-38 (fibroblasts) and CCD-841 CoN (colon epithelium). RA exhibited a concentration-dependent inhibitory effect on cancer cell metabolic activity, with colorectal cancer cells showing relatively higher sensitivity, particularly at shorter incubation times. To distinguish between cytotoxic and cytostatic effects, we performed trypan blue exclusion combined with a cell density assessment, clonogenic assay, and BrdU incorporation assay. The results from these complementary assays confirmed that RA acts primarily through an antiproliferative mechanism rather than by inducing cytotoxicity. In addition, NF-κB reporter assays demonstrated that RA attenuates TNF-α-induced transcriptional activation at higher concentrations, supporting its proposed anti-inflammatory properties and potential to modulate pro-tumorigenic signaling. Finally, our in silico studies predicted that RA may interact with proteins such as CAII, CES1, EGFR, and PLA2G2A, implicating it in the modulation of pathways related to proliferation and cell survival. Collectively, these findings suggest that RA may serve as a promising scaffold for the development of future anticancer agents, particularly in the context of colorectal cancer. Full article

Background/Objectives: Cancer remains a major global health challenge, driving the search for novel chemotherapeutic agents. This study aimed to evaluate the structural and biological properties of a series of Pd(II) complexes containing triphenylphosphine and thiosemicarbazone ligands, in order to assess their potential as anticancer agents. Methods: Six Pd(II) complexes with the general formula [PdCl(PPh₃)(TSC)] were synthesized and fully characterized by NMR (¹H, ¹³C, ³¹P), FTIR, mass spectrometry, and X-ray diffraction. Their cytotoxic effects were investigated through in vitro assays using 2D and 3D cancer cell models, including clonogenic, wound healing, cell cycle, and apoptosis assays via flow cytometry. Results: Complexes from the B family demonstrated significantly higher cytotoxicity than those from the C family, particularly against ovarian (IC₅₀ < 1 µM) and breast (IC₅₀~2 µM) cancer cell lines. These compounds exhibited superior potency and selectivity compared to cisplatin, with high selectivity indices toward non-tumor cells. Mechanistic studies revealed both cytotoxic and cytostatic effects depending on structural variations, with apoptosis identified as the primary mechanism of cell death. PdB1, in particular, induced a marked increase in late apoptotic populations and maintained its cytotoxic activity in 3D spheroid models by promoting disintegration, loss of cell adhesion, and nuclear fragmentation. Conclusions: The findings underscore the therapeutic promise of Pd(II) complexes, especially PdB1, as potent and selective antineoplastic agents capable of acting effectively in complex tumor environments and potentially overcoming chemoresistance. Full article

Background: Breast cancer (BC) is the most common cancer in women worldwide. Much progress has been made to improve treatment options for patients suffering from the disease, including a novel therapy—Poly (ADP-ribose) polymerase inhibitor (PARPi) that specifically targets tumors with deficiencies in the Homologous Recombination (HR) DNA repair pathway. To benefit better from conventional therapy, many patients seek alternative supplementation, with 20–30% of cancer patients using herbal medication on top of their regular treatment. An example of such easily available over-the-counter supplements is curcumin, a natural compound derived from turmeric (Curcuma longa). Various studies reported the potential HR deficiency (HRD) inducing effect of curcumin in cancer cells. Methods: Eight BrC and three normal cell lines and a BrC PDX model were used to evaluate the effect of curcumin on RAD51 ionizing radiation-induced focus (IRIF) formation. Three breast BrC cell lines underwent further analysis using the BRCA2 Western blot technique. To assess cell survival after treatment with curcumin and/or PARPi, a clonogenic survival assay was performed on both normal and cancerous cell lines. Results: Curcumin treatment led to a reduction in RAD51 IRIF formation capacity across all tested models. A decrease in BRCA2 levels was observed in the tested cell lines. Our findings demonstrate that HRD can be induced in both cancerous and normal cells, suggesting that curcumin treatment may increase the risk of toxicity when combined with PARPi therapy. Conclusions: The use of curcumin in combination with certain anti-cancer treatments should not be implemented without extensive monitoring for deleterious side effects. Full article

The treatment of choice for prostate cancer is androgen deprivation (ADT) and novel hormonal agents such as Abiraterone, Enzalutamide, or Apalutamide. Initially, this therapy is highly effective, but a significant challenge arises as most patients eventually develop resistance, resulting in castration-resistant prostate cancer (CRPC). Furthermore, the sequential use of these drugs can lead to cross-resistance, diminishing their efficacy. Tumor heterogeneity plays a pivotal role in the development of resistance to different treatments. This study utilized cellular models of CRPC to assess the response to Apalutamide when it was administered as a second- or third-line treatment. Functional and genetic analyses were conducted in various CRPC cell models exposed to Apalutamide. These analyses included real-time cell monitoring assays, flow cytometry, clonogenicity assays, and RT-qPCR. CRPC cell models were capable of continued proliferation, maintained cell cycle profiles similar to those of untreated cells, and retained their clonogenic potential. Cross-resistance to Apalutamide in models of ADT, ADT plus Enzalutamide, or Abiraterone resistance did not correlate with the expression levels of AR-V7 and AR-V9 variants. Gene expression analysis of resistant prostate cancer cell lines revealed that treatment with Apalutamide induced the emergence of more aggressive phenotypes, including cancer stem cells or neuroendocrine differentiation profiles. Most CRPC cell models developed cross-resistance to Apalutamide and were able to proliferate and retain their clonogenic capability. Apalutamide resistance was not linked to the expression of AR-V7 or AR-V9 variants but was instead associated to bypass of AR signaling pathway and the emergence of more aggressive expression profiles. Full article

Purpose: The development of acquired resistance to arginine deprivation therapy (ADT) is a major barrier to its efficacy. This study aimed to elucidate the possible mechanisms underlying the resistance to ADT. Methods: We applied repeated ADT and established a subline SAS-R9 of the human head and neck squamous cell carcinoma (HNSCC) cells semi-resistant to arginine (Arg) deprivation in vitro. This subline was compared to the parental SAS cell lines for its relative clonogenic proliferation, aggregation, adhesion, and migration capacities. The transcriptomic changes were assessed by RNA sequencing. Signaling pathway alterations were confirmed by RT-PCR and Western blotting. Relative cell radioresistance was analyzed by radiobiological clonogenic survival assay. DNA double-strand break (DSB) repair was assessed by γH2A.X foci analysis. Results: SAS-R9 cells showed higher survival in response to ADT and radiotherapy, elevated clonogenic proliferation rate, cell–cell aggregation, and cell–matrix adhesion, along with increased epithelial–mesenchymal transition (EMT) markers and enhanced DNA DSB repair, potentially related to a more aggressive and therapy-resistant phenotype. Conclusions: While acute ADT has radiosensitizing potential, this new study suggests that long-term, repeated ADT is associated with cell selection and reprogramming, resulting in resistance to radiotherapy-induced DNA damage and higher tumor cell aggressiveness. Full article

Background: Lung cancer is the leading cause of cancer-related death in the male sex worldwide. Non-small cell lung cancer (NSCLC) is the most prevalent type, accounting for 80–85% of cases, and lung adenocarcinoma is the most common and lethal NSCLC subtype, being responsible for ca. 50% of deaths. Despite new therapeutic strategies, lung cancer mortality rates remain high, highlighting the need for the development of new drugs. Objectives: We investigated the pharmacological potential of a series of curcumin-like compounds using two lung adenocarcinoma cell lines as models. Methods and Results: Cell viability assay led to the identification of PQM-214 as the hit compound, and other methodologies were employed to investigate the mechanisms underlying its antitumor potential, including cell cycle analysis, mitotic index determination, assessment of clonogenic capacity, senescence-associated β-galactosidase and annexin V assays, quantitative PCR, and Western blot analyses. The mechanism of action of PQM-214 was investigated in A549 cells, revealing that it effectively inhibits cell proliferation by inducing cell cycle arrest, apoptosis, or senescence. Cell cycle key regulators were significantly modulated by PQM-214, with cyclin E2, MYC, and FOXM1 being downregulated, while senescence markers such as cyclin D1, CDKN1A (p21), IL-8, TIMP1, and TIMP2 were upregulated. Moreover, Western blot results revealed upregulation of cyclin D1 and p21 in PQM-214-treated samples, with a downregulation of cyclin B. Conclusions: PQM-214 seems to act on different molecular targets in lung adenocarcinoma cells, inhibiting cell proliferation and inducing apoptosis. Further studies will be conducted to explore whether PQM-214 can also act as a senolytic agent, which would reinforce its anticancer potential. Full article

Ferruginol, tanshinones and carnosol are considered privileged natural products due to their demonstrated diverse biological activities with relevance to cancer research. Globally, cancer continues to be a major contributor to mortality rates, making these compounds potentially valuable molecular scaffolds for further development as potential anticancer agents. In this work, a focused library of ferruginol, tanshinone IIA, and carnosol analogues was studied to examine their effectiveness against various solid tumor models. The compounds were efficiently synthesized from either methyl 12-hydroxy-dehydroabietate or 12-hydroxydehydroabietylamine in 1–3 step processes with good chemical yields. The compounds that were synthesized underwent a methodical evaluation using multiple biological tests (including viability assays, clonogenic assays, and mitochondrial membrane polarization measurements) to determine their ability to inhibit in vitro the growth of three breast cancer cell linages. It was determined that while most compounds exhibited biological activity, compounds 10 and 11 demonstrated significant efficacy against triple negative breast cancer cells. These compounds continue to show promising biological activity, suggesting that additional studies to understand their mechanisms of action would be valuable. Full article

Prostate cancer cell lines are particularly clinically homogenous, mostly representing metastatic states rather than localized disease. While there has been significant work in the development of additional models, few have been created without oncogenic transformation. We derived a primary prostate cancer cell line from a patient with localized Gleason 7 prostate cancer—designated CaB34—which spontaneously immortalized. We leveraged CaB34 to generate a paired radioresistant subline, CaB34-CF, using a clinically relevant fractionated radiotherapy schedule. These two paired cell lines were investigated extensively to determine their molecular characteristics and therapy responses. Both CaB34 and CaB34-CF express prostate-specific markers, including KRT18, NKX3.1, and AMACR. Multi-omic analyses using RNAseq and shotgun proteomics identified NNMT as the most significantly dysregulated component in CaB34-CF. A bioinformatic analysis determined that NNMT was more abundant within prostate tumors compared to benign prostate, suggesting a role in tumor progression. Knockdown studies of NNMT demonstrated significant radiosensitization of CaB34-CF cells, which was largely a result of increased radiation-induced cellular senescence. Growth as 3D organoids was significantly higher in the CaB34-CF line, and demonstrated a less structured pattern of expression of cytokeratin markers. Radiosensitization with NNMT siRNA was recapitulated in a 3D organoid clonogenic assay in CaB34-CF cells. Our research provides a paired primary model of treatment-naïve and radioresistant disease to address mechanisms of therapy resistance, while expanding the repertoire of localized prostate cancer cell lines for the research community. In addition, our findings present NNMT as a potential therapeutic target for sensitization of radioresistant disease. Full article

Background/objectives: Brain cancer remains difficult to treat, with survival statistics stagnant for decades. The resistance of glioblastoma brain tumours can greatly challenge the effectiveness of conventional cancer radiotherapy. However, high dose rate radiotherapy has unique effects that allow for normal tissue sparing whilst maintaining tumour control. The addition of targeted radiosensitisers, such as the chemotherapeutic drug methotrexate (MTX) or the high-Z halogenated pyrimidine drug iododeoxyuridine (IUdR), can improve radiotherapy outcomes. Combining these radiosensitiser agents with ultra-high dose rate (UHDR) synchrotron X-rays can bear synergistic effects to enhance the efficacy of these multi-modal UHDR therapies, providing a means to overcome the radioresistance of brain cancer. Methods: Here, we use controlled in vitro assays following treatment, including a clonogenic assay to determine long-term cell survival and γH2AX immunofluorescent confocal microscopy to quantify double-strand DNA breaks (DSBs). Results: We find significant enhancement for highly synergistic combinations of IUdR+MTX with synchrotron X-rays. Cell survival results demonstrate 5.4 times increased 9L gliosarcoma cell killing when these agents are combined with UHDR synchrotron X-rays compared with conventional X-rays alone at the same 5 Gy dose. The underlying mechanisms are unveiled using γH2AX imaging and reveal significant increases in DSBs and dying cells following exposure to UHDR radiation. Conclusions: Our results demonstrate that highly synergistic combination treatments using UHDR synchrotron radiation can yield significantly improved brain cancer killing compared with conventional radiotherapy. We anticipate that these additive, multi-modal combination therapies will provide options for more targeted and effective use of radiotherapies for the future treatment of brain cancer. Full article

Quantitative phosphoproteomics enables the comprehensive analysis of signaling pathways driven by overexpressed cancer receptors, revealing the molecular mechanisms that underpin tumor progression and therapy resistance. The glycoprotein L1 cell adhesion molecule (L1CAM) is overexpressed in high-grade serous ovarian carcinoma (HGSOC) and plays a crucial role in carcinogenesis by regulating cancer stem cell properties. Here, CRISPR–Cas9-mediated knockout of L1CAM in ovarian cancer OVCAR8 and OVCAR4 cells significantly impaired anchor-independent growth in soft agar assays and reduced clonogenic survival following external beam irradiation. In vivo, L1CAM knockout decreased cancer stem cell frequency and significantly decreased tumorigenicity. To uncover L1CAM-regulated signaling networks, we employed quantitative phosphoproteomics and proteomics. Bioinformatics analyses and validation studies revealed L1CAM-associated pathways that contribute to radioresistance through DNA repair processes and mammalian target or rapamycin complex 1 (mTORC1)-mediated signaling. In conclusion, our study established a link between L1CAM-dependent tumorigenesis and radioresistance, both hallmarks of cancer stemness, with phosphorylation of key proteins involved in DNA damage response. This study further emphasizes the value of quantitative phosphoproteomics in cancer research, showcasing its ability to enhance understanding of cancer progression and therapy resistance. Full article