PD-1 inhibitor combined with chemotherapy for first-line treatment of esophageal squamous cell carcinoma patients with distant metastasis: a real-world retrospective study.

Background: The aim of this study was to evaluate whether the efficacy and safety of PD-1 inhibitors combined with chemotherapy in the treatment of patients with esophageal squamous cell carcinoma (ESCC) with distant metastasis in the real world are as effective and safe as in clinical trials. Patients and methods: From July 2019 to July 2023, a total of 422 patients with distant metastasis of ESCC were included and divided into the PD-1 inhibitor combined chemotherapy group (PC group) and the chemotherapy alone group (C group) according to the treatment regimen. There were 278 patients in the PC group and 144 patients in the C group. The primary endpoint of this study was progression-free survival (PFS), while secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety. Results: The objective response rate (ORR) and disease control rate (DCR) of the PC group were 44.60% (124/278) and 91.00% (253/278), respectively, which were 18.9% and 3.5% higher than those of the C group. The median PFS and median OS of the PC group were significantly better than those of the C group (median PFS: 6.5 vs. 5.5 months, P < 0.001; median OS: 16.6 vs. 13.9 months, P = 0.002). Further univariate and multivariate Cox analysis showed that the Eastern Cooperative Oncology Group performance status (ECOG PS) score and the number of metastatic sites were potential predictors of PFS in PC patients. The combination of PD-1 inhibitors with cisplatin and paclitaxel (TP) was more beneficial for patients with PFS compared to the combination of cisplatin and fluorouracil (PF). Furthermore, the presence of bone metastasis, body mass index (BMI), and lymphocyte-to-monocyte ratio (LWR) before treatment may be potential predictive factors for patient OS. The adverse reactions that occurred in the PC group can be tolerated or alleviated after both prevention and active treatment. Conclusions: The combination of PD-1 inhibitors and chemotherapy as first-line treatment for ESCC patients with distant metastasis still has good efficacy and safety compared to clinical trials in the real world.

Effects of bone marrow sparing radiotherapy on acute hematologic toxicity for patients with locoregionally advanced cervical cancer: a prospective phase II randomized controlled study.

OBJECTIVE: To evaluate effects of bone marrow sparing (BMS) radiotherapy on decreasing the incidence of acute hematologic toxicity (HT) for locoregionally advanced cervical cancer (LACC) patients treated by pelvic irradiation. MATERIALS AND METHODS: LACC patients were recruited prospectively from May 2021 to May 2022 at a single center and were evenly randomized into the BMS group and the control group. All patients received pelvic irradiation with concurrent cisplatin (40 mg/m2 weekly), followed by brachytherapy and BM V40 < 25% in the BMS group was additionally prescribed. Acute HT was assessed weekly. Binary logistic regression model and receiver operating characteristic (ROC) curve were used for predictive value analysis. The trial was registered with Chinese clinical trial registry (ChiCTR2200066485). RESULTS: A total of 242 patients were included in the analysis. Baseline demographic, disease and treatment characteristics were balanced between the two groups. In the intention-to-treat population, BMS was associated with a lower incidence of grade ≥ 2 and grade ≥ 3 acute HT, leukopenia and neutropenia s(72.70% v 90.90%, P < 0.001*; 16.50% vs. 65.30%, P < 0.001*; 66.10% vs. 85.10%, P = 0.001*; 13.20% vs. 54.50%, P < 0.001*; 37.20% vs. 66.10%, P < 0.001*; 10.70% vs. 43.80%, P < 0.001*). BMS also resulted in decreased dose delivered to the organs at risk (OARs) including rectum, bladder and left and right femoral head. Univariate and multivariate analyses showed that BM V40 was an independent risk factor for grade ≥ 3 acute HT (odds ratio [OR] = 2.734, 95% confidence interval [CI] = 1.959-3.815, P < 0.001*). Cutoff value was 25.036% and area under the curve (AUC) was 0.786. The nomogram was constructed, which was rigorously evaluated and internally cross-validated, showing good predictive performance. CONCLUSIONS: Receiving BMS pelvic irradiation could reduce the incidence of acute HT in LACC patients, and BM V40 < 25% may be a significant factor in reducing the risks of acute HT.

FAM120A deficiency improves resistance to cisplatin in gastric cancer by promoting ferroptosis.

The occurrence of chemoresistance is an inescapable obstacle affecting the clinical efficacy of cisplatin in gastric cancer (GC). Exploring the regulatory mechanism of cisplatin resistance will help to provide potential effective targets for improving the prognosis of gastric cancer patients. Here, we find that FAM120A is upregulated in GC tissues and higher in cisplatin-resistant GC tissues, and its high expression is positively correlated with the poor outcome of GC patients. Functional studies indicate that FAM120A confers chemoresistance to GC cells by inhibiting ferroptosis. Mechanically, METTL3-induced m6A modification and YTHDC1-induced stability of FAM120A mRNA enhance FAM120A expression. FAM120A inhibits ferroptosis by binding SLC7A11 mRNA and enhancing its stability. FAM120A deficiency enhances cisplatin sensitivity by promoting ferroptosis in vivo. These results reveal the function of FAM120A in chemotherapy tolerance and targeting FAM120A is an effective strategy to alleviate cisplatin resistance in GC.

Evaluation of a new score associated with acute kidney injury in patients treated with cisplatin based EXTREME regimen.

BACKGROUND: This study evaluates the association of diuresis and hydration through a new monitoring indicator called U sen and the risk of acute kidney injury in patients treated with cisplatin based-EXTREME regimen. METHODS: We retrospectively reviewed all the cycles of patients with recurrent and/or metastatic head and neck cancer who received cisplatin based-EXTREME regimen from June 2008 to July 2022. Hydration regimen, urine output and concomitant treatments data were collected on the day of cisplatin infusion and the following day of each course received. RESULTS: Of the 110 courses received by 46 patients, 38 (34.5%) results in AKI. No patient characteristics showed a significant difference between AKI (70%) and non-AKI (30%) group. In univariate analysis, dose reduction of cisplatin (odds ratio = 0.166 [0.04; 0.75], p = 0.01)) and U sen >8 (odds ratio = 0.316 [0.133; 0.755], p = 0.015) and cardiac treatments (odds ratio = 3.24 [1.26; 8.52], p = 0.02) were significantly associated with AKI risk. In multivariate analysis, cisplatin dose reduction (odds ratio = 0.129 [0.0241; 0.687], p = 0.016) and U sen >8 (odds ratio = 0.184 [0.0648; 0.523], p = 0.0015) were associated with a risk reduction of cisplatin-related AKI. Concomitant administration of cardiac treatments (odds ratio = 3.18 [1.1; 9.22], p = 0.033) showed an increased risk of cisplatin-related AKI. CONCLUSION: The combination of diuresis and i.v. hydration through the U sen composite score was shown to be associated with cisplatin-induced AKI risk in patients treated with cisplatin based EXTREME regimen. It could be used as a practical indicator to trigger specific clinical management to limit the risk of cisplatin induced AKI.

PRMT4 interacts with NCOA4 to inhibit ferritinophagy in cisplatin-induced acute kidney injury.

Cisplatin-induced acute kidney injury (AKI) is commonly seen in the clinical practice, and ferroptosis, a type of non-apoptotic cell death, plays a pivotal role in it. Previous studies suggested that protein arginine methyltransferase 4 (PRMT4) was incorporated in various bioprocesses, but its role in renal injuries has not been investigated. Our present study showed that PRMT4 was highly expressed in renal proximal tubular cells, and it was downregulated in cisplatin-induced AKI. Besides, genetic disruption of PRMT4 exacerbated, while its overexpression attenuated, cisplatin-induced redox injuries in renal proximal epithelia. Mechanistically, our work showed that PRMT4 interacted with NCOA4 to inhibit ferritinophagy, a type of selective autophagy favoring lipid peroxidation to accelerate ferroptosis. Taken together, our study demonstrated that PRMT4 interacted with NCOA4 to attenuate ferroptosis in cisplatin-induced AKI, suggesting that PRMT4 might present as a new therapeutic target for cisplatin-related nephropathy.

A phase II/III randomized clinical trial of CisPlatin plUs Gemcitabine and Nabpaclitaxel (GAP) as pReoperative chemotherapy versus immediate resection in patIents with resecTable BiliarY Tract Cancers (BTC) at high risk for recurrence: PURITY study.

BACKGROUND: Biliary tract cancers (BTCs) are rare and lethal cancers, with a 5-year survival inferior to 20%(1-3). The only potential curative treatment is surgical resection. However, despite complex surgical procedures that have a remarkable risk of postoperative morbidity and mortality, the 5-year survival rate after radical surgery (R0) is 20-40% and recurrence rates are up to ~ 75%(4-6). Up to ~ 40% of patients relapse within 12 months after resection, and half of these patient will recur systemically(4-6). There is no standard of care for neoadjuvant chemotherapy (NAC) in resectable BTC, but retrospective reports suggest its potential benefit (7, 8). METHODS: PURITY is a no-profit, multicentre, randomized phase II/III trial aimed at evaluating the efficacy of the combination of gemcitabine, cisplatin and nabpaclitaxel (GAP) as neoadjuvant treatment in patients with resectable BTC at high risk for recurrence. Primary objective of this study is to evaluate the efficacy of neoadjuvant GAP followed by surgery as compared to upfront surgery, in terms of 12-month progression-free survival for the phase II part and of progression free survival (PFS) for the phase III study. Key Secondary objectives are event free survival (EFS), relapse-free survival, (RFS), overall survival (OS), R0/R1/R2 resection rate, quality of life (QoL), overall response rate (ORR), resectability. Safety analyses will include toxicity rate and perioperative morbidity and mortality rate. Exploratory studies including Next-Generation Sequencing (NGS) in archival tumor tissues and longitudinal ctDNA analysis are planned to identify potential biomarkers of primary resistance and prognosis. DISCUSSION: Considering the poor prognosis of resected BTC experiencing early tumor recurrence and the negative prognostic impact of R1/R2 resections, PURITY study is based on the rationale that NAC may improve R0 resection rates and ultimately patients' outcomes. Furthermore, NAC should allow early eradication of microscopic distant metastases, undetectable by imaging but already present at the time of diagnosis and avoid mortality and morbidity associated with resection for patients with rapid progression or worsening general condition during neoadjuvant therapy. The randomized PURITY study will evaluate whether patients affected by BTC at high risk from recurrence benefit from a neoadjuvant therapy with GAP regimen as compared to immediate surgery. TRIAL REGISTRATION: PURITY is registered at ClinicalTrials.gov (NCT06037980) and EuCT(2023-503295-25-00).

Galectin-3 and Autophagy in Renal Acute Tubular Necrosis.

Acute kidney injury (AKI) is a public health burden with increasing morbidity and mortality rates and health care costs. Acute tubular necrosis (ATN) is the most common cause of AKI. Cisplatin (CIS) is a platinum-based chemotherapeutic agent used in the treatment of a wide variety of malignancies such as lung, breast, ovary, testis, bladder, cervix, and head and neck cancers. Autophagy plays an important role in AKI. Galectin-3 (Gal-3) is significantly increased in renal tubules in AKI; however, its role in autophagy is not well understood. Male C57B6/J and B6.Cg-Lgals3 /J Gal-3 knockout (KO) mice were used to induce AKI using a CIS mouse model of ATN. Renal Gal-3 and autophagy proteins' expression were measured using standard histologic, immunofluorescent, and enzyme-linked immunosorbent assay techniques. The data were presented as the mean ± S.E. Statistically significant differences (p < 0.05) were calculated between experimental groups and corresponding control groups by one-way analysis of variance. There was a significant increase in renal concentrations of Gal-3 in the Gal-3 wild-type CIS-treated mice when compared with sham control mice. There were significantly higher concentrations of renal LC3B, ATG13, Ulk-1, Beclin, ATG5, ATG12, ATG9A, and p-AMPK in the CIS-treated Gal-3 KO mice than in the Gal-3 wild-type CIS-treated mice. Further, there were significantly higher concentrations of mTOR, p- NF-κB, beta-catenin, and p62 in the kidneys of the Gal-3 wild-type CIS-treated mice than in the Gal-3 KO CIS-treated mice. Our findings affirm the connection between Gal-3 and autophagy, revealing its central role as a connector with prosurvival signaling proteins. Gal-3 plays a pivotal role in orchestrating cellular responses by interacting with prosurvival signal pathways and engaging with autophagy proteins. Notably, our observations highlight that the absence of Gal-3 can enhance autophagy in CIS-induced ATN.

Fraxetin pretreatment alleviates cisplatin-induced kidney injury by antagonizing autophagy and apoptosis via mTORC1 activation.

Cisplatin-induced kidney injury (CKI) is a common complication of chemotherapy. Fraxetin, derived from Fraxinus bungeana A. DC. bark, has antioxidant, anti-inflammatory, and anti-fibrotic effects. This study aims to investigate fraxetin's effects on CKI and its underlying mechanism in vivo and in vitro. Tubular epithelial cells (TECs) and mice were exposed to cisplatin with and without fraxetin preconditioning assess fraxetin's role in CKI. TECs autophagy was observed using transmission electron microscopy. Apoptosis levels in animal tissues were measured using TUNEL staining. The protective mechanism of fraxetin was explored through pharmacological and genetic regulation of mTORC1. Molecular docking was used to identify potential binding sites between fraxetin and mTORC1. The results indicated that fraxetin pretreatment reduced cisplatin-induced kidney injury in a time- and concentration-dependent way. Fraxetin also decreased autophagy in TECs, as observed through electron microscopy. Tissue staining confirmed that fraxetin pretreatment significantly reduced cisplatin-induced apoptosis. Inhibition of mTORC1 using rapamycin or siRNA reversed the protective effects of fraxetin on apoptosis and autophagy in cisplatin-treated TECs, while activation of mTORC1 enhanced fraxetin's protective effect. Molecular docking analysis revealed that fraxetin can bind to HEAT-repeats binding site on mTORC1 protein. In  summary, fraxetin pretreatment alleviates CKI by antagonizing autophagy and apoptosis via mTORC1 activation. This provides evidence for the potential therapeutic application of fraxetin in CKI.

SF3A2 promotes progression and cisplatin resistance in triple-negative breast cancer via alternative splicing of MKRN1.

Triple-negative breast cancer (TNBC) is the deadliest subtype of breast cancer owing to the lack of effective therapeutic targets. Splicing factor 3a subunit 2 (SF3A2), a poorly defined splicing factor, was notably elevated in TNBC tissues and promoted TNBC progression, as confirmed by cell proliferation, colony formation, transwell migration, and invasion assays. Mechanistic investigations revealed that E3 ubiquitin-protein ligase UBR5 promoted the ubiquitination-dependent degradation of SF3A2, which in turn regulated UBR5, thus forming a feedback loop to balance these two oncoproteins. Moreover, SF3A2 accelerated TNBC progression by, at least in part, specifically regulating the alternative splicing of makorin ring finger protein 1 (MKRN1) and promoting the expression of the dominant and oncogenic isoform, MKRN1-T1. Furthermore, SF3A2 participated in the regulation of both extrinsic and intrinsic apoptosis, leading to cisplatin resistance in TNBC cells. Collectively, these findings reveal a previously unknown role of SF3A2 in TNBC progression and cisplatin resistance, highlighting SF3A2 as a potential therapeutic target for patients with TNBC.

miR-125b reverses cisplatin resistance by regulating autophagy via targeting RORA/BNIP3L axis in lung adenocarcinoma.

The platinum-based chemotherapy is one of the most frequently used treatment protocols for lung adenocarcinoma (LUAD), and chemoresistance, however, usually results in treatment failure and limits its application in the clinic. It has been shown that microRNAs (miRNAs) play a significant role in tumor chemoresistance. In this study, miR-125b was identified as a specific cisplatin (DDP)-resistant gene in LUAD, as indicated by the bioinformatics analysis and the real-time quantitative PCR assay. The decreased serum level of miR-125b in LUAD patients was correlated with the poor treatment response rate and short survival time. MiR-125b decreased the A549/DDP proliferation, and the multiple drug resistance- and autophagy-related protein expression levels, which were all reversed by the inhibition of miR-125b. In addition, xenografts of human tumors in nude mice were suppressed by miR-125b, demonstrating that through autophagy regulation, miR-125b could reverse the DDP resistance in LUAD cells, both in vitro and in vivo. Further mechanistic studies indicated that miR-125b directly repressed the expression levels of RORA and its downstream BNIP3L, which in turn inhibited autophagy and reversed chemoresistance. Based on these findings, miR-125b in combination with DDP might be an effective treatment option to overcome DDP resistance in LUAD.

Reducing renal function assessment prior to platinum-based chemotherapy: a real-world evaluation.

BACKGROUND: Platinum-based chemotherapy, a widely used backbone of systemic cytotoxic anticancer treatment, is associated with nephrotoxicity. Currently, renal function is generally assessed prior to each administration of cisplatin or carboplatin, but there is no guideline regarding the frequency of renal function determination. OBJECTIVE: The primary objective was to determine the median time to a clinically relevant dosage adjustment (>10%) due to change in renal function in patients treated with cisplatin and carboplatin. Secondly, variables influencing changes in renal function were assessed. METHODS: We conducted a retrospective analysis of serial renal function assessments in platinum-treated patients with cancer in two academic medical centers, using a query to extract data from the electronic health records between 2017 and 2019. RESULTS: In total, 512 patients receiving cisplatin and 628 patients receiving carboplatin were included. In total, 15% of all cisplatin-treated patients were found to have a renal function less than 60 mL/min at least once during treatment, with a median time to renal function decline of 67 days (range 5-96 days), which did not differ between treatment regimens. For carboplatin 21% of patients were found to have had a dosage variation of more than 10% at least once during treatment, with a median time-to-event period of 64 days (range 5-100 days). INTERPRETATION: Dose adjustments during platinum-based chemotherapy resulting from renal function decline occur after a median time of ≥64 days. Our data provide substantiated guidance to recommend renal function assessment during platinum-based chemotherapy in clinically stable patients to once every 3 weeks.

Babaodan overcomes cisplatin resistance in cholangiocarcinoma via inhibiting YAP1.

CONTEXT: Cholangiocarcinoma with highly heterogeneous, aggressive, and multidrug resistance has a poor prognosis. Although babaodan (BBD) combined with cisplatin improved non-small cell lung cancer efficacy, its impact on overcoming resistance in cholangiocarcinoma remains unexplored. OBJECTIVE: This study explored the role and mechanism of BBD on cisplatin resistance in cholangiocarcinoma cells (CCAs). MATERIALS AND METHODS: Cisplatin-resistant CCAs were exposed to varying concentrations of cisplatin (25-400 µg/mL) or BBD (0.25-1.00 mg/mL) for 48 h. IC50 values, inhibition ratios, apoptosis levels, DNA damage, glutathione (GSH) levels, oxidized forms of GSH, total GSH content, and glutaminase relative activity were evaluated using the cell counting kit 8, flow cytometry, comet assay, and relevant assay kits. RESULTS: BBD-reduced the cisplatin IC50 in CCAs from 118.8 to 61.83 µg/mL, leading to increased inhibition rate, apoptosis, and DNA damage, and decreased expression of B-cell lymphoma-2, p-Yes-associated protein 1/Yes-associated protein 1, solute carrier family 1 member 5, activating transcription factor 4, and ERCC excision repair 1 in a dose-dependent manner with maximum reductions of 78.97%, 51.98%, 54.03%, 56.59%, and 63.22%, respectively; bcl2-associated X and gamma histone levels were increased by 0.43-115.77% and 22.15-53.39%. The impact of YAP1 knockdown on cisplatin-resistant CCAs resembled BBD. GSH, oxidized GSH species, total GSH content, and glutaminase activity in cisplatin-resistant CCAs with BBD treatment also decreased, while YAP1 overexpression countered BBD's effects. DISCUSSION AND CONCLUSION: This study provides a scientific basis for BBD clinical application and provides a new direction for BBD biological mechanism research.

Endometrial stem cells alleviate cisplatin-induced ferroptosis of granulosa cells by regulating Nrf2 expression.

BACKGROUND: Premature ovarian failure (POF) caused by cisplatin is a severe and intractable sequela for young women with cancer who received chemotherapy. Cisplatin causes the dysfunction of granulosa cells and mainly leads to but is not limited to its apoptosis and autophagy. Ferroptosis has been also reported to participate, while little is known about it. Our previous experiment has demonstrated that endometrial stem cells (EnSCs) can repair cisplatin-injured granulosa cells. However, it is still unclear whether EnSCs can play a repair role by acting on ferroptosis. METHODS: Western blotting and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) were applied to detect the expression levels of ferroptosis-related genes. CCK-8 and 5-Ethynyl-2'-deoxyuridine (EdU) assays were used to evaluate cell viability. Transmission electron microscopy (TEM) was performed to detect ferroptosis in morphology. And the extent of ferroptosis was assessed by ROS, GPx, GSSG and MDA indicators. In vivo, ovarian morphology was presented by HE staining and the protein expression in ovarian tissue was detected by immunohistochemistry. RESULTS: Our results showed that ferroptosis could occur in cisplatin-injured granulosa cells. Ferroptosis inhibitor ferrostatin-1 (Fer-1) and EnSCs partly restored cell viability and mitigated the damage of cisplatin to granulosa cells by inhibiting ferroptosis. Moreover, the repair potential of EnSCs can be markedly blocked by ML385. CONCLUSION: Our study demonstrated that cisplatin could induce ferroptosis in granulosa cells, while EnSCs could inhibit ferroptosis and thus exert repair effects on the cisplatin-induced injury model both in vivo and in vitro. Meanwhile, Nrf2 was validated to participate in this regulatory process and played an essential role.

MicroRNA Expression Profiles in Human Samples and Cell Lines Revealed Nine miRNAs Associated with Cisplatin Resistance in High-Grade Serous Ovarian Cancer.

Metastasis and drug resistance are major contributors to cancer-related fatalities worldwide. In ovarian cancer (OC), a staggering 70% develop resistance to the front-line therapy, cisplatin. Despite proposed mechanisms, the molecular events driving cisplatin resistance remain unclear. Dysregulated microRNAs (miRNAs) play a role in OC initiation, progression, and chemoresistance, yet few studies have compared miRNA expression in OC samples and cell lines. This study aimed to identify key miRNAs involved in the cisplatin resistance of high-grade-serous-ovarian-cancer (HGSOC), the most common gynecological malignancy. MiRNA expression profiles were conducted on RNA isolated from formalin-fixed-paraffin-embedded human ovarian tumor samples and HGSOC cell lines. Nine miRNAs were identified in both sample types. Targeting these with oligonucleotide miRNA inhibitors (OMIs) reduced proliferation by more than 50% for miR-203a, miR-96-5p, miR-10a-5p, miR-141-3p, miR-200c-3p, miR-182-5p, miR-183-5p, and miR-1206. OMIs significantly reduced migration for miR-183-5p, miR-203a, miR-296-5p, and miR-1206. Molecular pathway analysis revealed that the nine miRNAs regulate pathways associated with proliferation, invasion, and chemoresistance through PTEN, ZEB1, FOXO1, and SNAI2. High expression of miR-1206, miR-10a-5p, miR-141-3p, and miR-96-5p correlated with poor prognosis in OC patients according to the KM plotter database. These nine miRNAs could be used as targets for therapy and as markers of cisplatin response.

Transcriptomic Changes in Cisplatin-Resistant MCF-7 Cells.

Breast cancer is a leading cause of cancer-related deaths among women. Cisplatin is used for treatment, but the development of resistance in cancer cells is a significant concern. This study aimed to investigate changes in the transcriptomes of cisplatin-resistant MCF7 cells. We conducted RNA sequencing of cisplatin-resistant MCF7 cells, followed by differential expression analysis and bioinformatic investigations to identify changes in gene expression and modified signal transduction pathways. We examined the size and quantity of extracellular vesicles. A total of 724 genes exhibited differential expression, predominantly consisting of protein-coding RNAs. Notably, two long non-coding RNAs (lncRNAs), NEAT1 and MALAT, were found to be dysregulated. Bioinformatic analysis unveiled dysregulation in processes related to DNA synthesis and repair, cell cycle regulation, immune response, and cellular communication. Additionally, modifications were observed in events associated with extracellular vesicles. Conditioned media from resistant cells conferred resistance to wild-type cells in vitro. Furthermore, there was an increase in the number of vesicles in cisplatin-resistant cells. Cisplatin-resistant MCF7 cells displayed differential RNA expression, including the dysregulation of NEAT1 and MALAT long non-coding RNAs. Key processes related to DNA and extracellular vesicles were found to be altered. The increased number of extracellular vesicles in resistant cells may contribute to acquired resistance in wild-type cells.

A Stem-like Patient-Derived Ovarian Cancer Model of Platinum Resistance Reveals Dissociation of Stemness and Resistance.

To understand chemoresistance in the context of cancer stem cells (CSC), a cisplatin resistance model was developed using a high-grade serous ovarian cancer patient-derived, cisplatin-sensitive sample, PDX4. As a molecular subtype-specific stem-like cell line, PDX4 was selected for its representative features, including its histopathological and BRCA2 mutation status, and exposed to cisplatin in vitro. In the cisplatin-resistant cells, transcriptomics were carried out, and cell morphology, protein expression, and functional status were characterized. Additionally, potential signaling pathways involved in cisplatin resistance were explored. Our findings reveal the presence of distinct molecular signatures and phenotypic changes in cisplatin-resistant PDX4 compared to their sensitive counterparts. Surprisingly, we observed that chemoresistance was not inherently linked with increased stemness. In fact, although resistant cells expressed a combination of EMT and stemness markers, functional assays revealed that they were less proliferative, migratory, and clonogenic-features indicative of an underlying complex mechanism for cell survival. Furthermore, DNA damage tolerance and cellular stress management pathways were enriched. This novel, syngeneic model provides a valuable platform for investigating the underlying mechanisms of cisplatin resistance in a clinically relevant context, contributing to the development of targeted therapies tailored to combat resistance in stem-like ovarian cancer.

The Catalytic Activity of Human REV1 on Undamaged and Damaged DNA.

Eukaryotic REV1 serves as a scaffold protein for the coordination of DNA polymerases during DNA translesion synthesis. Besides this structural role, REV1 is a Y-family DNA polymerase with its own distributive deoxycytidyl transferase activity. However, data about the accuracy and efficiency of DNA synthesis by REV1 in the literature are contrasting. Here, we expressed and purified the full-length human REV1 from Saccharomyces cerevisiae and characterized its activity on undamaged DNA and a wide range of damaged DNA templates. We demonstrated that REV1 carried out accurate synthesis opposite 8-oxoG and O6-meG with moderate efficiency. It also replicated thymine glycol surprisingly well in an error-prone manner, but was blocked by the intrastrand 1,2-GG cisplatin crosslink. By using the 1,N6-ethenoadenine and 7-deaza-adenine lesions, we have provided biochemical evidence of the importance for REV1 functioning of the Hoogsteen face of template A, the second preferable template after G.

Folate-modified liposomes mediate the co-delivery of cisplatin with miR-219a-5p for the targeted treatment of cisplatin-resistant lung cancer.

Cisplatin (DDP) resistance, often leading to first-line chemotherapy failure in non-small cell lung cancer (NSCLC), poses a significant challenge. MiR-219a-5p has been reported to enhance the sensitivity of human NSCLC to DDP. However, free miR-219a-5p is prone to degradation by nucleases in the bloodstream, rendering it unstable. In light of this, our study developed an efficient nanodrug delivery system that achieved targeted delivery of DDP and miR-219a-5p by modifying liposomes with folate (FA). Based on the results of material characterization, we successfully constructed a well-dispersed and uniformly sized (approximately 135.8 nm) Lipo@DDP@miR-219a-5p@FA nanodrug. Agarose gel electrophoresis experiments demonstrated that Lipo@DDP@miR-219a-5p@FA exhibited good stability in serum, effectively protecting miR-219a-5p from degradation. Immunofluorescence and flow cytometry experiments revealed that, due to FA modification, Lipo@DDP@miR-219a-5p@FA could specifically bind to FA receptors on the surface of tumor cells (A549), thus enhancing drug internalization efficiency. Safety evaluations conducted in vitro demonstrated that Lipo@DDP@miR-219a-5p@FA exhibited no significant toxicity to non-cancer cells (BEAS-2B) and displayed excellent blood compatibility. Cellular functional experiments, apoptosis assays, and western blot demonstrated that Lipo@DDP@miR-219a-5p@FA effectively reversed DDP resistance in A549 cells, inhibited cell proliferation and migration, and further promoted apoptosis. In summary, the Lipo@DDP@miR-219a-5p@FA nanodrug, through specific targeting of cancer cells and reducing their resistance to DDP, significantly enhanced the anti-NSCLC effects of DDP in vitro, providing a promising therapeutic option for the clinical treatment of NSCLC.

Nobiletin alleviates cisplatin-induced ototoxicity via activating autophagy and inhibiting NRF2/GPX4-mediated ferroptosis.

Nobiletin, a citrus polymethoxy flavonoid with antiapoptotic and antioxidative properties, could safeguard against cisplatin-induced nephrotoxicity and neurotoxicity. Cisplatin, as the pioneer of anti-cancer drug, the severe ototoxicity limits its clinical applications, while the effect of nobiletin on cisplatin-induced ototoxicity has not been identified. The current study investigated the alleviating effect of nobiletin on cisplatin-induced ototoxicity and the underlying mechanisms. Apoptosis and ROS formation were evaluated using the CCK-8 assay, Western blotting, and immunofluorescence, indicating that nobiletin attenuated cisplatin-induced apoptosis and oxidative stress. LC3B and SQSTM1/p62 were determined by Western blotting, qPCR, and immunofluorescence, indicating that nobiletin significantly activated autophagy. Nobiletin promoted the nuclear translocation of NRF2 and the transcription of its target genes, including Hmox1, Nqo1, and ferroptosis markers (Gpx4, Slc7a11, Fth, and Ftl), thereby inhibiting ferroptosis. Furthermore, RNA sequencing analysis verified that autophagy, ferroptosis, and the NRF2 signaling pathway served as crucial points for the protection of nobiletin against ototoxicity caused by cisplatin. Collectively, these results indicated, for the first time, that nobiletin alleviated cisplatin-elicited ototoxicity through suppressing apoptosis and oxidative stress, which were attributed to the activation of autophagy and the inhibition of NRF2/GPX4-mediated ferroptosis. Our study suggested that nobiletin could be a prospective agent for preventing cisplatin-induced hearing loss.

Anti-cancer effects of alpha lipoic acid, cisplatin and paclitaxel combination in the OVCAR-3 ovarian adenocarcinoma cell line.

BACKGROUND: Ovarian cancer is the leading cause of gynecological cancer deaths. One of the major challenges in treating ovarian cancer with chemotherapy is managing the resistance developed by cancer cells to drugs, while also minimizing the side effects caused by these agents In the present study, we aimed to examine the effects of a combination of alpha lipoic acid (ALA), with cisplatin and paclitaxel in ovarian cancer(OVCAR-3). METHODS: The cytotoxic effects of ALA, cisplatin and paclitaxel on OVCAR-3 cells were determined. Four groups were formed: Control, ALA, Cisplatin + Paclitaxel, ALA + Cisplatin + Paclitaxel. The effects of single and combined therapy on cell migration, invasion and colony formation were analyzed. Changes in the expression of genes related to apoptosis, cell adhesion and cell cycle were analyzed with Real-time polymerase chain reaction(RT-PCR). The oxidative stress index and The Annexin V test were performed. RESULTS: The reduction in rapamycin-insensitive companion of mTOR(RICTOR) expression in the ALA + Cisplatin + Paclitaxel group was found statistically significant(p < 0.05). The decrease in MMP-9 and - 11 expressions the ALA + Cisplatin + Paclitaxel group was statistically significant(p < 0.05). The lowest values for mitogen-activated protein kinase(MAPK) proteins were found in the ALA + Cisplatin + Paclitaxel group. No colony formation was observed in the Cisplatin + Paclitaxel and ALA + Cisplatin + Paclitaxel groups. The lowest wound healing at 24 h was seen in the ALA + Cisplatin + Paclitaxel group. CONCLUSIONS: This study is the first one to investigate the combined treatment of ALA, Cisplatin, Paclitaxel on OVCAR-3. While ALA alone was not effective, combined therapy with ALA, has been found to reduce cell invasion, especially wound healing in the first 24 h, along with tumor cell adhesion.