Search Results (861)

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. It is characterized by the clonal proliferation of mature B cells. The tumor microenvironment (TME) seems to play a crucial role in the survival and proliferation of tumor cells. Multiple new classes of drugs had been approved for the management of patients with CLL, reshaping the treatment paradigm. The most important classes are Bruton’s tyrosine kinase (BTK) inhibitors and BCL-2 inhibitors. Both of them are approved as a first-line treatment in patients with CLL requiring treatment. The role of BTK and BCL-2 in the signaling pathways of the TME is very important. The aim of this review is to summarize the major components of the TME and the available data regarding targeted therapies in CLL. Full article

Acute myeloid leukemia (AML), a heterogeneous and aggressive clonal disease, is predominantly observed in older individuals, with a median age at diagnosis of 68–69 years. With the aging population, there is a significant increase in the occurrence of some genetic alterations, including detrimental gene mutations and cytogenetic abnormalities, and a higher incidence of secondary AML (s-AML) and therapy-related AML (t-AML), compared to younger AML patients. Outcomes of AML patients and their response to therapy are associated with the molecular features of AML subtypes and with individual variables. The current criteria for risk classification predict outcomes in younger AML patients treated with intensive chemotherapy but are less predictive for older AML patients treated with lower-intensity treatments. Thus, this review analyzes and discusses the development of new risk stratification models adapted to the study of older AML patients and how these new criteria may significantly contribute to a more rational classification and treatment of older AML patients. Full article

Cellular senescence is a state of the durable cell cycle arrest of dysfunctional cells, which has been associated with the promotion of tumor cell reprogramming into a stem cell state. We previously reported that the mixed lineage kinase (MLK) inhibitor CEP-1347 promotes the differentiation of glioma stem cells (GSCs)—key contributors to glioblastoma recurrence and therapy resistance—into non-stem tumor cells. However, we also noted that CEP-1347–treated GSCs exhibited a morphological change suggestive of senescence. Therefore, we herein investigated whether CEP-1347 induces senescence in GSCs and, consequently, if senescent GSCs may be eliminated using senolytics. Cell death induced by CEP-1347 in combination with senolytic agents or with the knockdown of anti-apoptotic BCL2 family genes, as well as the effects of CEP-1347 on the expression of senescence markers and anti-apoptotic Bcl-2 family proteins, were examined. The results obtained showed that CEP-1347 induced senescence in GSCs accompanied by the increased expression of Bcl-xL. Among the panel of senolytic agents tested, navitoclax, a BH3 mimetic, efficiently induced cell death in GSCs when combined with CEP-1347 at concentrations clinically achievable in the brain. The knockdown of Bcl-xL resulted in more pronounced GSC death in combination with CEP-1347 than that of Bcl-2. These results suggest that combining CEP-1347 with the targeting of Bcl-xL, the expression of which increases with CEP-1347-induced senescence, is a rational approach to ensure the elimination of GSCs, thereby improving the outcomes of glioblastoma treatment. Full article

Cancer remains one of the most formidable challenges to human health; hence, developing effective treatments is critical for saving lives. An important strategy involves reactivating tumor suppressor genes, particularly p53, by targeting their negative regulator MDM2, which is essential in promoting cell cycle arrest and apoptosis. Leveraging a drug repurposing approach, we screened over 24,000 clinically tested molecules to identify new MDM2 inhibitors. A key innovation of this work is the development and application of a selective cleaning algorithm that systematically filters assay data to mitigate noise and inconsistencies inherent in large-scale bioactivity datasets. This approach significantly improved the predictive accuracy of our machine learning model for pIC₅₀ values, reducing RMSE by 21.6% and achieving state-of-the-art performance (R² = 0.87)—a substantial improvement over standard data preprocessing pipelines. The optimized model was integrated with structure-based virtual screening via molecular docking to prioritize repurposing candidate compounds. We identified two clinical CB1 antagonists, MePPEP and otenabant, and the statin drug atorvastatin as promising repurposing candidates based on their high predicted potency and binding affinity toward MDM2. Interactions with the related proteins MDM4 and BCL2 suggest these compounds may enhance p53 restoration through multi-target mechanisms. Quantum mechanical (ONIOM) optimizations and molecular dynamics simulations confirmed the stability and favorable interaction profiles of the selected protein–ligand complexes, resembling that of navtemadlin, a known MDM2 inhibitor. This multiscale, accuracy-boosted workflow introduces a novel data-curation strategy that substantially enhances AI model performance and enables efficient drug repurposing against challenging cancer targets. Full article

CLL is the most prevalent adult leukemia in Western countries, characterized by the accumulation of monoclonal B lymphocytes. Over the past decade, the therapeutic landscape for CLL has undergone significant transformations, primarily due to the introduction of targeted small molecular therapies like BTK inhibitors and BCL-2 inhibitors, that have improved patient outcomes drastically. Despite significant advances, long-term disease management remains challenging for patients with double-refractory CLL, where responses with subsequent therapies are short-lived. Resistance to these therapies can arise through several mechanisms like kinase-altering BTK mutations, alterations in the BCL-2 pathway, and adaptations within the tumor microenvironment, necessitating the exploration of new therapeutic options. This review provides an in-depth overview of the promising novel treatment approaches under investigation in CLL, focusing on advanced cellular therapies (CAR T-cell therapy), T-cell engagers, new monoclonal antibodies, and various next-generation small molecule inhibitors including BTK degraders, PI3K inhibitors, MALT1 inhibitors, c-MYC inhibitors, CDK9 inhibitors, and agents targeting angiogenesis and DNA damage repair. In this review, we will discuss the novel therapeutic targets and agents as well as ongoing trials, emphasizing the potential of these treatments to overcome resistance and meet the unmet needs of patients, particularly those with double-refractory CLL. Full article

Background: The treatment landscape for multiple myeloma (MM) has significantly evolved in recent decades with novel therapies like proteasome inhibitors, immunomodulatory drugs and monoclonal antibodies. However, MM remains incurable, necessitating new pharmacological strategies. Mitotic kinases, such as Aurora proteins, have emerged as potential targets. Selective inhibitors of Aurora A and B,- alisertib (MLN8237) and barasertib (AZD1152), respectively, have shown anti-myeloma activity in preclinical studies, with alisertib demonstrating modest efficacy in early clinical trials. Methods and Results: This study investigated the mechanisms of action of alisertib and barasertib and their combination with antitumor agents in a panel of five MM cells lines. Both drugs induced cell cycle arrest phase and abnormal nuclear morphologies. Alisertib caused prolonged mitotic arrest, whereas barasertib induced transient arrest, both resulting in the activation of mitotic catastrophe. These findings revealed three potential outcomes: cell death, senescence, or polyploidy. High mitochondrial reactive oxygen species (mROS) were identified as possible drivers of cell death. Caspase inhibition reduced caspase-3 activation but did not prevent cell death. Interestingly, alisertib at low doses remained toxic to Bax/Bak^DKO cells, although mitochondrial potential disruption and cytochrome c release were observed. Sequential combinations of high-dose Aurora kinase inhibitors with BH3-mimetics, and in specific cases with panobinostat, showed a synergistic effect. Conversely, the simultaneous combination of alisertib and barasertib showed mostly antagonistic effects. Conclusions: Alisertib and barasertib emerge as potential in vitro candidates against MM, although further studies are needed to validate their efficacy and to find the best combinations with other molecules. Full article

Current systemic therapies for advanced colorectal cancer (CRC) have limited efficacy, so more effective strategies for the treatment and prevention of CRC are needed. The majority of colorectal cancers are initiated by mutations in Wnt signalling pathway genes, including mutations in the APC gene, which result in a truncated APC protein and lead to excess signalling from β-catenin and the formation of pre-cancerous adenomas. The aim of this study was to determine if targeting the Wnt pathway in combination with pro-apoptotic mimetics altered the proliferative capacity or viability of human colorectal adenoma cells. Patient-derived colorectal adenoma organoid cultures were established from colon adenoma tissue collected by colonoscopy and recapitulated the histopathology of primary colorectal adenoma tissue. The growth of colorectal adenoma organoids is inhibited by the Wnt-signalling antagonist pyrvinium pamoate (PP) and a pro-apoptotic inhibitor of BCL-XL but not BCL-2 (venetoclax) or MCL-1 inhibitors. At low concentrations, the PP and the BCL-XL inhibitor combination demonstrated potent synergy and induced apoptosis in APC-defective patient-derived adenoma organoids, even in the presence of oncogenic KRAS or BRAF mutations, providing a new strategy for colon cancer prevention. Full article

Background: Chronic lymphocytic leukemia (CLL) is a prevalent hematologic malignancy that predominantly affects elderly individuals, posing significant clinical challenges due to patient comorbidities and inherent resistance to conventional chemotherapy. The emergence of targeted therapies combining venetoclax, a selective inhibitor of the anti-apoptotic protein BCL-2, with anti-CD20 monoclonal antibodies has dramatically transformed the treatment landscape. Methods: This retrospective observational study analyzed the differential impacts of first-line venetoclax-obinutuzumab (VenO) and second-line venetoclax-rituximab (VenR) on immunoglobulin G (IgG) levels and absolute neutrophil count (ANC) in CLL patients. Results: Our findings indicate that during first-line VenO therapy, a significant improvement in ANC levels from baseline was observed, whereas patients undergoing second-line VenR therapy demonstrated limited impact on ANC and the decreasing tendency in IgG levels. Patients treated with VenR had a longer disease history and previous exposure to other treatment regimens, primarily chemoimmunotherapy, which could negatively influence immune recovery, making direct comparisons between these two treatment lines challenging. Although this observational study did not directly compare infection rates, the observed enhancement of ANC levels in patients receiving VenO suggests a potential for lower infection risk compared to pretreated VenR patients. Conclusions: These results underscore the clinical significance of considering both the treatment line and the patient’s prior therapeutic history when selecting venetoclax-based regimens for CLL. The potential association of first-line VenO with improved immunological parameters and the complex impact of prior therapies on immunological recovery with second-line VenR warrant further prospective investigation into the correlation between treatment regimen, patient history, immune function, and infectious complications. Full article

The resistance of breast cancer cells to therapeutic antibodies such as anti-HER2 trastuzumab can be overcome by engaging natural killer (NK) cells for killing antibody-binding tumor cells via antibody-dependent cellular cytotoxicity (ADCC). Here, we investigated how autophagy modulation affects trastuzumab-mediated ADCC in HER2-positive JIMT1 breast cancer cells and NK cells. Autophagy inducers (rapamycin and resveratrol) had no significant impact, but the inhibitor bafilomycin nearly abolished ADCC. Protection occurred when either cancer or NK cells were pretreated, indicating dual effects. Bafilomycin reduced phosphatidylserine externalization, the loss of plasma membrane integrity, caspase-3/7 activity, and DNA fragmentation. It downregulated pro-apoptotic BAK1 and BAX without altering BCL-2. Additionally, bafilomycin decreased HER2 surface expression, impairing trastuzumab binding, and modulated immune regulators (STAT1, CD95, and PD-L1) in NK and/or in the cancer cells. Bafilomycin disrupted HER2 trafficking and induced HER2 internalization, leading to its accumulation in cytoplasmic vesicles. These findings show that autophagy inhibition by bafilomycin confers ADCC resistance by altering apoptosis, immune signaling, and HER2 dynamics. The study underscores autophagy’s role in antibody-based cancer therapy efficacy. Full article

Ovarian cancer cells overexpress HDAC6, and selective HDAC6 inhibitors have been considered potential new drugs for ovarian cancer either alone or in combination with other anticancer agents. We screened 46 potential novel HDAC6 inhibitors in ES-2 ovarian cancer cells and showed that compound 25253 demonstrated the most potent anti-proliferative activity and effective synergy with paclitaxel, which was also validated in TOV21G ovarian cancer cells. The combination of 25253 and paclitaxel significantly induced subG1 and apoptotic cells, revealed by PI staining assay and Annexin V-FITC/PI double staining assay, respectively. Western blot analysis showed downregulation of Bcl-2 and Bcl-XL, and upregulation of Bax and Bak, indicating that apoptosis was mediated through the intrinsic pathway. The combination increased γ-H2AX and p-p53 protein levels, suggesting the induction of DNA damage. Furthermore, HDAC6 was downregulated and acetylated α-tubulin was profoundly increased. Compound 25253 enhanced the inhibitory effect of paclitaxel on cell migration and invasion, possibly due to the extensive accumulation of acetylated α-tubulin, which affected microtubule dynamics. Taken together, the combination of 25253 and paclitaxel synergistically inhibited the growth, migration, and invasion of ovarian cancer cells and induced apoptosis, providing supporting evidence that the combination of HDAC6 inhibitors and paclitaxel may be a promising treatment strategy for ovarian cancer. Full article

Background/Objectives: Vancomycin-induced nephrotoxicity (VIN) remains a significant clinical challenge, with no effective nephroprotective agent currently established. This study aimed to evaluate the protective effects of the sodium–glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin (DAPA) against VIN in a Wistar albino rat model. Methods: Rats were randomly assigned to four groups: control, VA (vancomycin), DAPA (dapagliflozin), and VA+DAPA. Renal function was assessed by measuring serum urea and creatinine. Oxidative stress markers [malondialdehyde (MDA), total oxidant status (TOS), and myeloperoxidase (MPO)], antioxidant enzyme activities [total antioxidant status (TAS), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD)], apoptotic mediators (Bax, Bcl-2, and caspase-3), and pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6)] were evaluated. Histopathological and immunohistochemical analyses of kidney tissues were also performed. Results: Administration of VA led to significant renal dysfunction, increased oxidative stress, heightened apoptotic activity, and notable histopathological damage. Co-administration of DAPA with VA significantly reduced serum urea and creatinine levels and decreased caspase-3 activity and was associated with a trend toward reduction in both MDA levels and TNF-α expression, as well as the amelioration of histopathological renal injury. However, reductions in IL-1β and IL-6 levels were not statistically significant. Overall, these findings indicate that DAPA exerts nephroprotective effects against VIN by modulating oxidative stress, inflammation, and apoptotic pathways. Conclusions: Dapagliflozin may serve as a potential protective agent against vancomycin-induced nephrotoxicity. Further long-term and large-scale clinical studies are warranted to validate these preclinical findings and explore their therapeutic implications. Full article

Head and neck squamous cell carcinoma (HNSCC) remains challenging to treat despite multimodal therapeutic approaches. Cisplatin treatment is effective and cost-efficient, although chemoresistance and disease recurrence limit its efficacy. Understanding the mechanisms of cisplatin resistance and the identification of compounds to target resistant tumor cells are critical for improving patient outcomes. We have demonstrated that cisplatin-induced senescent HN30 HNSCC cells can be eliminated by ABT-263 (navitoclax), a BCL-2/BCL-X_L inhibitor that has senolytic properties. Here, we report the development of a cisplatin-resistant cell line (HN30R) for the testing of ABT-263 and the PROTAC BET degraders ARV-825 and ARV-771. ABT-263 was ineffective in sensitizing HN30R cells to cisplatin, largely due to a lack of senescence induction. However, the BET degraders in combination with cisplatin promoted apoptotic cell death in both HN30 and HN30R cells. The effectiveness of ARV-825 did not appear to depend on the cells entering into senescence, indicating that it was not acting as a conventional senolytic. ARV-825 treatment downregulated BRD4 and its downstream targets, c-Myc and Survivin, as well as decreased the expression of RAD51, a DNA repair marker. These results suggest that the BET degraders ARV-825 and ARV-771 may be effective in improving the response of chemoresistant head and neck cancer to cisplatin treatment. Full article

Aberrant activation of the mitogen-activated protein kinase (MAPK) cascade promotes oncogenic transcriptomes. Despite efforts to inhibit oncogenic kinases, such as BRAFV600E, tumor responses in patients can be heterogeneous and limited by drug resistance mechanisms. Here, we describe patient tumors that acquired COP1 or DET1 mutations after treatment with the BRAF^V600E inhibitor vemurafenib. COP1 and DET1 constitute the substrate adaptor of the E3 ubiquitin ligase CRL4^COP1/DET1, which targets transcription factors, including ETV1, ETV4, and ETV5, for proteasomal degradation. MAPK-MEK-ERK signaling prevents CRL4^COP1/DET1 from ubiquitinating ETV1, ETV4, and ETV5, but the mechanistic details are still being elucidated. We found that patient mutations in COP1 or DET1 inactivated CRL4^COP1/DET1 in melanoma cells, stabilized ETV1, ETV4, and ETV5, and conferred resistance to inhibitors of the MAPK pathway. ETV5, in particular, enhanced cell survival and was found to promote the expression of the pro-survival gene BCL2A1. Indeed, the deletion of pro-survival BCL2A1 re-sensitized COP1 mutant cells to vemurafenib treatment. These observations indicate that the post-translational regulation of ETV5 by CRL4^COP1/DET1 modulates transcriptional outputs in ERK-dependent cancers, and its inactivation contributes to therapeutic resistance. Full article

This study investigates the role of melatonin in alleviating the oxidative stress and apoptosis of TM3 Leydig cells induced by 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), the primary active metabolite of Bisphenol A, and clarifies its potential mechanisms involving the SIRT1/PGC-1α pathway. We found that melatonin effectively mitigated MBP-induced cytotoxicity in TM3 cells (p < 0.05). The testosterone levels and steroid hormone synthesis proteins were significantly restored by melatonin. Furthermore, there was a significant reduction in apoptosis after melatonin treatment both in MBP-treated TM3 cells and Bisphenol A-treated testicular interstitial tissues (p < 0.05), along with a significant decrease in the pro-apoptotic markers Bax and cleaved caspase 3, and a significant increase in the anti-apoptotic Bcl-2 level and the Bcl-2/Bax ratio in TM3 cells (p < 0.05). Additionally, the mitochondrial membrane potential improved significantly, ROS and MDA levels were down-regulated, and ATP production was elevated following melatonin treatment in TM3 cells. Mechanistically, melatonin promoted PGC-1α expression and activated the SIRT1 signaling pathway in MBP-treated TM3 cells and Bisphenol A-treated testicular interstitial tissues. This leads to increased expression of NRF2 and its downstream antioxidant genes, mitochondrial respiratory chain complex-related genes, mitochondrial biogenesis genes, and mitochondrial fusion genes while significantly reducing mitochondrial fission genes (p < 0.05). The PGC-1α inhibitor SR-18292 reversed these protective effects, confirming the critical role of this pathway. Conclusively, melatonin exerts a protective effect against MBP-induced oxidative stress and apoptosis in TM3 cells through the SIRT1/PGC-1α pathway, indicating its potential as a therapeutic agent for improving male reproductive health compromised by environmental toxins. Full article