Efficacy Of Gemcitabine Research Articles

Phase 2 trial of avelumab in combination with gemcitabine in advanced leiomyosarcoma as a second-line treatment (EAGLES, Korean Cancer Study Group UN18-09).

In this single-arm, multicenter, phase 2 trial, the authors evaluated the efficacy and safety of avelumab plus gemcitabine in patients with leiomyosarcoma (LMS) who failed on first-line chemotherapy. Patients with advanced LMS received avelumab 10 mg/kg on days 1 and 15 (for up to 24 months) plus gemcitabine 1000 mg/m2 on days 1, 8, and 15 of a 28-day cycle until they developed disease progression or intolerable toxicity. The primary end point was the objective response rate (ORR). In total, 38 patients were enrolled. Of these, 35 patients were evaluable, and the ORR was 20% (95% confidence interval; [CI], 8%-37%). The disease control rate was 71%, and the median duration of response was 21.8 months (range, 7.6 to ≥43.3 months). The median progression free-survival was 5.6 months (95% CI, 4.5-6.8 months), and the median overall survival was 27.5 months (95% CI, 20.4-34.6 months). Grade 3-4 adverse events occurred in 70% of patients, of which neutropenia was the most common (54%). Immune-mediated adverse events occurred in five patients (14%; hypothyroidism, n=3; hepatitis, n=2). Patients who had a higher density of tumor-infiltrating lymphocytes (greater than the median) exhibited better ORR (35% vs. 8%; p=.104), progression-free survival (median, 7.3 vs. 3.3 months; p=.024), and overall survival (median, not reached vs. 21.5 months; p=.027). The combination of avelumab and gemcitabine demonstrated promising efficacy and manageable safety in patients with advanced LMS who progressed on first-line therapy. Tumor-infiltrating lymphocyte density may be an important factor in predicting the response to combining immunotherapy with chemotherapy.

A phase 2 trial of gemcitabine plus toripalimab for cisplatin-ineligible patients with recurrent or metastatic nasopharyngeal carcinoma

Cisplatin is a cornerstone chemotherapy for nasopharyngeal carcinoma (NPC); however, certain patients are ineligible for cisplatin-based regimens. This phase 2 trial (NCT04405622) evaluated the efficacy and safety of gemcitabine and toripalimab in previously untreated patients with recurrent or metastatic NPC who were either ineligible for cisplatin or had experienced severe adverse events from prior cisplatin-based treatments. Patients received gemcitabine (1,000mg/m2) and toripalimab (240mg) every three weeks for six cycles, followed by toripalimab monotherapy for up to two years. The primary endpoint was the incidence of grade ≥3 adverse events, while secondary endpoints included objective response rate (ORR) and overall survival (OS). Of 30 screened patients, 21 were enrolled. No treatment-related fatalities occurred, with the most frequent adverse events being headache and nausea. The ORR was 61.9%, coupled with a disease control rate of 100%. Overall, gemcitabine plus toripalimab demonstrated low toxicity and promising efficacy for this specific patient cohort.

Flurbiprofen inhibits cAMP transport by MRP4/ABCC4 increasing the potency of gemcitabine treatment in PDAC cell models

Pancreatic ductal adenocarcinoma (PDAC) remains a highly malignant cancer with a grim prognosis due to its early metastasis and resistance to current chemotherapies, such as Gemcitabine (GEM). We have previously demonstrated that cAMP exclusion by MRP4 is critical for PDAC cell proliferation, establishing this transporter as a promising prognostic marker and therapeutic target. In search for novel therapeutic options to improve GEM efficacy, we conducted a drug repositioning screening to identify potential inhibitors of cAMP transport by MRP4. Several non-steroidal anti-inflammatory drugs (NSAIDs) can inhibit the transport of certain MRP4 substrates. In this study, we assessed the efficacy of sixteen NSAIDs in inhibiting cAMP transport mediated by MRP4, identifying seven potent inhibitors based on their IC50 values. The most potent inhibitors were further tested for their effect on cell proliferation and migration. Flurbiprofen emerged as the most potent inhibitor of both MRP4-mediated cAMP transport and cell proliferation. Overexpression of MRP4 in BxPC-3 cells significantly increased GEM resistance, and co-administration of flurbiprofen with GEM markedly enhanced the latter's potency inhibiting PDAC cells proliferation. These findings position flurbiprofen as a potent inhibitor of cAMP transport by MRP4 and a promising adjunctive therapy to enhance GEM effectiveness in PDAC treatment.

Abstract C031: Keratin 17 promotes pancreatic cancer chemoresistance through mitochondrial translocation and stabilization of dihydroorotate dehydrogenase (DHODH)

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) has emerged as the third leading cause of cancer-related deaths in the U.S., in part, due to intrinsic resistance to main-line chemotherapeutic protocols. Our prior data showed that the upregulation of pyrimidine but not purine de novo biosynthesis is associated with shortened survival of patients whose tumors expresses high keratin 17 (K17). Furthermore, we reported that K17 expression confers chemoresistance by impacting the inner mitochondrial membrane protein, dihydroorotate dehydrogenase (DHODH), the rate-limiting enzyme in the de novo pyrimidine synthesis pathway1. Here, we explore the mechanisms through which K17 enters mitochondria, stabilizes DHODH, and thereby, enhances downstream de novo pyrimidine biosynthesis and chemoresistance. Methods: We generated a KPC K17 stably expressing cell line and a L3.6 K17 knockout cell line to assess the effects of K17 on cell viability and performed western blot, immunoprecipitation, mass spectrometry, immunofluorescence imaging, and cellular sub- fractionation. We also generated wild type K17, MLS mutant K17 and coil 2 deletion K17 overexpression in L3.6 K17 KO and KPC cell lines to study the importance of MLS and coil 2 domains. Results: Our previous studies suggested that K17 drives chemoresistance by increasing mitochondrial DHODH, elevating intracellular pyrimidines. In our current report, we identified by Mitoprot a mitochondria localization signal (MLS) of K17 with a probability of 86% and validated that it is required for K17 to enter the mitochondria and impact DHODH. Mechanistically, we found that K17 enters the mitochondria by specifically interacting with the translocase of the outer mitochondrial membrane complex (TOM20/TOM40). Additionally, we uncovered a coil 2 domain of K17 that mediates DHODH stability at the inner mitochondrial membrane. Our data showed that K17 with deletion of the coil 2 domain fails to interact with DHODH suggesting that this domain is critical for mediating interaction and DHODH stabilization. By contrast, MLS mutant K17 did not enter the mitochondria and promote DHODH stabilization, thus having no impact in altering the downstream de novo pyrimidine synthesis. Furthermore, we found that MLS mutant or coil 2 deleted K17 expressing cells have increased sensitivity towards gemcitabine, compared to wild type K17 expressing cells. Conclusions: We report for the first time that K17 encodes an MLS, enabling K17 to enter mitochondria, and that the coil 2 domain of K17 stabilizes DHODH at the inner mitochondrial membrane, thereby upregulating de novo pyrimidine biosynthesis and chemoresistance to gemcitabine. Further studies are warranted to explore whether a therapeutic strategy targeting K17 mitochondrial transport or interaction with DHODH could enhance the therapeutic efficacy of gemcitabine or other pyrimidine analog-based pharmacologic agents. 1. Pan et. al. Targeting keratin 17- mediated reprogramming of de novo pyrimidine biosynthesis to overcome chemoresistance in pancreatic cancer. bioRxiv, 2022 Citation Format: Yinghuan Lyu, Monisankar Ghosh, Chun-Hao Pan, Shayan Sarkar, Girish H Rajacharya, Bo Chen, Natalia Marchenko, Pankaj K Singh, Kenneth R. Shroyer, Luisa F. Escobar-Hoyos. Keratin 17 promotes pancreatic cancer chemoresistance through mitochondrial translocation and stabilization of dihydroorotate dehydrogenase (DHODH) [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C031.

The efficacy of gemcitabine and docetaxel chemotherapy for the treatment of relapsed and refractory osteosarcoma: A systematic review and pre-clinical study.

Osteosarcoma is the most common primary malignancy of the bone. There is a lack of effective treatments for patients who experience relapsed osteosarcoma. One treatment for relapsed patients is gemcitabine and docetaxel combination chemotherapy (GEMDOX). This systematic review aimed to establish the efficacy of this chemotherapy regimen, as well as identify the common severe toxicities that are associated with it. Resistant osteosarcoma cell lines developed from MG-63 and HOS-143B were used to represent relapsed osteosarcoma patients in a pre-clinical study. We identified 11 retrospective and Phase II studies that were suitable for inclusion in our review. 10.65% of patients had a response to gemcitabine and docetaxel combination therapy and the disease control rate was 35% (n = 197). 36%, 35.3% and 18.04% of patients experienced grade 3 or 4 neutropenia, thrombocytopenia and anaemia respectively (n = 133). Male patients (X2 = 9.14, p < 0.05) and those below the age of 18 (X 2 = 10.94, p < 0.05) responded better to GEMDOX treatment than females and patients older than 18 years. The resistant osteosarcoma cell lines remained sensitive to either single-agent gemcitabine, docetaxel, and the combination of both. Cisplatin-resistant models (MG-63/CISR8 & HOS-143B/CISR8) were the most responsive to GEMDOX treatment compared to doxorubicin, methotrexate, and triple-combination resistant models. GEMDOX treatment has potential efficacy in relapsed osteosarcoma patients especially those with cisplatin resistance. To directly compare the efficacy of GEMDOX therapy against other therapies randomised phase III clinical trials with adequate patient follow up must be performed to improve treatment options for osteosarcoma.

1530P Preliminary result of a phase Ib study: Efficacy and safety of FG-M108 plus gemcitabine and nab-paclitaxel in patients with Claudin18.2 positive locally advanced unresectable or metastaticpancreatic cancer

1530P Preliminary result of a phase Ib study: Efficacy and safety of FG-M108 plus gemcitabine and nab-paclitaxel in patients with Claudin18.2 positive locally advanced unresectable or metastaticpancreatic cancer

Anticancer effects of high-dose extracellular citrate treatment in pancreatic cancer cells under different glucose concentrations

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive solid tumor. Recently, the uptake of extracellular citrate by the sodium-dependent citrate transporter (NaCT), encoded by SLC13A5, has been demonstrated to exert profound effects on cancer cell metabolism. However, research on the function of extracellular citrate in PDAC pathogenesis and the relationship between NaCT expression and the tumor metabolic microenvironment is limited. Therefore, we aimed to evaluate the expression of citrate transporters across a spectrum of glucose concentrations in pancreatic cancer and systematically explore the effects of sodium citrate treatment on pancreatic cancer cells at different glucose concentrations. We observed a positive correlation between glucose concentration and NaCT expression in PDAC cell lines. Extracellular sodium citrate significantly reduced cell viability partially due to reduction in intracellular Ca2+ levels and decreased the migration of human PDAC cells. Furthermore, we observed a decrease in the levels of the stem cell marker prominin I (CD133) following sodium citrate treatment. Notably, the combination treatment of gemcitabine and extracellular sodium citrate exhibited a synergistic anticancer effect in both two-dimensional (2D) and three-dimensional (3D) culture systems. Additionally, we confirmed that pH slightly increased upon administration of sodium citrate, indicating that this could potentially augment the efficacy of gemcitabine. Altogether, these findings suggest that exogenous sodium citrate treatment, particularly in combination with gemcitabine, may represent a novel therapeutic strategy for treating PDAC. This approach holds promise for disrupting PDAC cell metabolism and inhibiting tumor progression.

1523P Efficacy of gemcitabine plus nab-paclitaxel in second-line treatment of metastatic pancreatic cancer

1523P Efficacy of gemcitabine plus nab-paclitaxel in second-line treatment of metastatic pancreatic cancer

Clinical utility of BRCA and ATM mutation status in circulating tumour DNA for treatment selection in advanced pancreatic cancer.

Identification of homologous recombination deficiency (HRD) remains a challenge in advanced pancreatic cancer (APC). We investigated the utility of circulating tumour DNA (ctDNA) profiling in the assessment of BRCA1/2 and ATM mutation status and treatment selection in APC. We analysed clinical and ctDNA data of 702 patients with APC enroled in GOZILA, a ctDNA profiling study using Guardant360. Inactivating BRCA1/2 and ATM mutations were detected in 4.8% (putative germline, 3.7%) and 4.4% (putative germline, 0.9%) of patients, respectively. Objective response (63.2% vs. 16.2%) and PFS (HR 0.55, 95% CI 0.32-0.93) on platinum-containing chemotherapy were significantly better in patients with putative germline BRCA1/2 (gBRCA) mutation than those without. In contrast, putative gBRCA mutation had no impact on the efficacy of gemcitabine plus nab-paclitaxel. In 2 patients treated with platinum-containing therapy, putative BRCA2 reversion mutations were detected. Three of seven patients with somatic BRCA mutations responded to platinum-containing therapy, while only one of four with putative germline ATM mutations did. One-third of somatic ATM mutations were in genomic loci associated with clonal haematopoiesis. Comprehensive ctDNA profiling provides clinically relevant information regarding HRD status. It can be a practical, convenient option for HRD screening in APC.

Inhibition of MSH6 augments the antineoplastic efficacy of cisplatin in non-small cell lung cancer as autophagy modulator

The altered response to chemotherapeutic agents predominantly stems from heightened single-point mutations within coding regions and dysregulated expression levels of genes implicated in drug resistance mechanisms. The identification of biomarkers based on mutation profiles and expression levels is pivotal for elucidating the underlying mechanisms of altered drug responses and for refining combinatorial therapeutic strategies in the field of oncology. Utilizing comprehensive bioinformatic analyses, we investigated the impact of eight mismatch repair (MMR) genes on overall survival across 23 cancer types, encompassing more than 7500 tumors, by integrating their mutation profiles. Among these genes, MSH6 emerged as the most predictive biomarker, characterized by a pronounced mutation frequency and elevated expression levels, which correlated with poorer patient survival outcomes.The wet lab experiments disclosed the impact of MSH6 in mediating altered drug responses. Cytotoxic assays conducted revealed that the depletion of MSH6 in H460 non-small lung cancer cells augmented the efficacy of cisplatin, carboplatin, and gemcitabine. Pathway analyses further delineated the involvement of MSH6 as a modulator, influencing the delicate equilibrium between the pro-survival and pro-death functions of autophagy.Our study elucidates the intricate interplay between MSH6, autophagy, and cisplatin efficacy, highlighting MSH6 as a potential therapeutic target to overcome cisplatin resistance. By revealing the modulation of autophagy pathways by MSH6 inhibition, our findings offer insights into novel approaches for enhancing the efficacy of cisplatin-based cancer therapy through targeted interventions.

Enhancement of gemcitabine sensitivity in intrahepatic cholangiocarcinoma through Saikosaponin-a mediated modulation of the p-AKT/BCL-6/ABCA1 axis

BackgroundIntrahepatic cholangiocarcinoma (ICC) remains a significant challenge in cancer therapy, especially due to its resistance to established treatments like Gemcitabine, necessitating novel therapeutic approaches. MethodsThis study utilized Gemcitabine-resistant cell lines, patient-derived organotypic tumor spheroids (PDOTs), and patient-derived xenografts (PDX) to evaluate the effects of Saikosaponin-a (SSA) on ICC cellular proliferation, migration, apoptosis, and its potential synergistic interaction with Gemcitabine. Techniques such as transcriptome sequencing, Luciferase reporter assays, and molecular docking were employed to unravel the molecular mechanisms. ResultsSSA exhibited antitumor effects in both in vitro and PDX models, indicating its considerable potential for ICC treatment. SSA markedly inhibited ICC progression by reducing cellular proliferation, enhancing apoptosis, and decreasing migration and invasion. Crucially, it augmented Gemcitabine's efficacy by targeting the p-AKT/BCL6/ABCA1 signaling pathway. This modulation led to the downregulation of p-AKT and suppression of BCL6 transcriptional activity, ultimately reducing ABCA1 expression and enhancing chemosensitivity to Gemcitabine. Additionally, ABCA1 was validated as a predictive biomarker for drug resistance, with a direct correlation between ABCA1 expression levels and the IC50 values of various small molecule drugs in ICC gene profiles. ConclusionThis study highlights the synergistic potential of SSA combined with Gemcitabine in enhancing therapeutic efficacy against ICC and identifies ABCA1 as a key biomarker for drug responsiveness. Furthermore, the introduction of the novel PDOTs microfluidic model provides enhanced insights into ICC research. This combination strategy may provide a novel approach to overcoming treatment challenges in ICC.

Targeting Pancreatic Cancer with Novel Nicolaioidesin C Derivatives: Molecular Mechanism, In Vitro, and In Vivo Evaluations.

Pancreatic cancer, one of the deadliest cancers with the lowest 5-year survival rate, often develops resistance to gemcitabine-based chemotherapies. The hypovascular nature of pancreatic tumors forces cancer cells to adapt to nutrient-depleted tumor microenvironments. Conventional anticancer agents targeting rapidly dividing cancer cells under nutrient-rich conditions are largely ineffective against adapted pancreatic cancer cells. Thus, targeting cancer cells under nutrient starvation, termed the "antiausterity strategy", may be effective for pancreatic cancer. This study examined nicolaioidesin C (Nic-C) derivatives as antiausterity agents. Among the 32 derivatives, Nic-15 (4n) exhibited superior cytotoxicity against MIA PaCa-2 and PANC-1 pancreatic cancer cells, inhibited MIA PaCa-2 cell migration and colony formation, and modulated the PI3K/Akt/mTOR pathway, while reducing the ER stress markers induced by gemcitabine. Nic-15 was found to inhibit tumor growth and enhance the efficacy of gemcitabine in an in vivo xenograft model. Nic-15 in combination with gemcitabine may be an effective strategy for the treatment of pancreatic cancer.

Bazedoxifene Inhibits Cell Viability, Colony-Forming Activity, and Cell Migration in Human Non-Small Cell Lung Cancer Cells and Improves the Treatment Efficacy of Paclitaxel and Gemcitabine.

Bazedoxifene is a third-generation selective estrogen receptor modulator that inhibits the IL6/IL6R/GP130 signaling pathway by inhibiting IL6-induced homodimerization of GP130. Considering that the IL6/IL6R/GP130 signaling pathway is important in tumorigenesis and metastasis, bazedoxifene is thought to have an antitumor effect, which has been proven preliminarily in breast cancer and pancreatic cancer but has not yet been studied in non-small cell lung cancer (NSCLC). This study is aimed at evaluating the antitumor effect of bazedoxifene in NSCLC. A549 and H1299 NSCLC cell lines were employed and exposed to various concentrations of bazedoxifene, paclitaxel, gemcitabine, and their combinations for cell viability, colony formation, and wound healing assays to demonstrate the antitumor effect of bazedoxifene with or without paclitaxel or gemcitabine. MTT cell viability, colony formation, and wound healing assays showed that bazedoxifene was capable of inhibiting cell viability, colony formation, and cell migration in a dose-dependent manner. In addition, bazedoxifene was capable of working with paclitaxel or gemcitabine synergistically to inhibit cell viability, colony formation, and cell migration. This study demonstrated the potential antitumor effect of bazedoxifene and its ability to improve the treatment efficacy of paclitaxel and gemcitabine.

Phase II study of nab-paclitaxel with gemcitabine for relapsed/refractory small cell lung cancer.

Patients with small cell lung cancer (SCLC) often respond to first-line chemoimmunotherapy. However, relapse is inevitable and is associated with a poor prognosis. Treatments for relapsed SCLC, such as lurbinectedin and topotecan, are limited by modest efficacy and significant hematologic adverse events, leaving a need for newer therapeutic agents or regimens. The combination of gemcitabine and nab-paclitaxel is active and safe in other types of malignancies, such as pancreatic cancer. We conducted a phase II trial evaluating the efficacy and safety of gemcitabine and nab-paclitaxel in patients with relapsed/refractory SCLC. The primary endpoint was objective response rate (ORR), defined as the proportion of patients with confirmed complete or partial response. Secondary endpoints included time to progression (TTP), progression-free survival (PFS), overall survival (OS), and safety. Between October 2016 and May 2021, 32 patients were enrolled. Patients were followed for a median of 9.3 months (range 1.8-65.2). Median age was 65 years (range 48-81). Fifty percent of patients were female. Fifty-three percent of patients had platinum-resistant/refractory relapsed SCLC. The ORR was 28.1% (95% confidence interval [CI] 15.5-100%). Median PFS was 2.9 months (95% CI 2.4-3.6), and median OS was 9.3 months (95% CI 5.2-12.4). Seven patients (21.9%) developed grade 3 or 4 neutropenia. Our study showed that the combination of gemcitabine and nab-paclitaxel led to encouraging outcomes in relapsed/refractory SCLC. Further studies are needed to compare this combination with other treatments used for relapsed SCLC, including lurbinectedin, temozolomide, and topotecan. https://clinicaltrials.gov/study/NCT02769832?cond=NCT02769832&rank=1, identifier NCT02769832.

Treatment of locally advanced pancreatic cancer using localized trans-arterial micro perfusion of gemcitabine: combined analysis of RR1 and RR2.

Locally advanced pancreatic cancer (LAPC) comprises 40% of pancreatic cancer diagnoses and has a relatively poor prognosis. Trans-arterial micro perfusion (TAMP)-mediated chemotherapy delivery to the primary tumor is a novel approach worthy of investigation. The RR1 (dose escalation) and RR2 (observational) studies examined the safety and preliminary efficacy of TAMP-delivered gemcitabine for LAPC. RR1 and RR2 data were pooled. Both studies enrolled patients with LAPC with histologically confirmed adenocarcinoma. Participant data, including age, sex, race, stage, previous treatments, toxicity, disease progression, and death, were collected. Median number of cycles and average treatment dosage were calculated. Overall survival (OS) was determined for the whole group and separately for patients who received and did not receive previous treatments. Aims of the analysis were to assess procedure safety, OS, and evaluate factors associated with OS. The median age of the 43 patients enrolled in RR1 and RR2 was 72 years (range, 51-88 years). Median OS for the 35 eligible patients with stage III disease was 12.6 months (95% CI, 2.1-54.2 months). Previous chemoradiation was associated with significantly longer OS [27.1 months (95% CI, 8.4-40.6 months)] compared to previous systemic chemotherapy [14.6 months (95% CI, 6.4-54.2 months)] or no prior treatment [7.0 months (95% CI, 2.1-35.4 months)] (P < .001). The most common adverse events were GI related (abdominal pain, emesis, and vomiting); the most common grade 3 toxicity was sepsis. Study results indicate that TAMP-mediated gemcitabine delivery in patients with LAPC is potentially safe, feasible, and provides potential clinical benefits. NCT02237157 (RR1) and NCT02591082 (RR2).

Comparing efficacy and safety of in-house gemcitabine to mitomycin for bladder instillation in intermediate-risk NMIBC

IntroductionIntermediate-risk (IR) Non-Muscle Invasive Bladder Cancer (NMIBC) is associated with a high rate of tumor recurrence. To improve patient outcomes, it is recommended to use adjuvant intravesical therapy, by mitomycin C (MMC) or Bacillus Calmette Guerin (BCG). Gemcitabine (GMC) is a known molecule used in urothelial cancer. We aimed to study the efficacy and safety profile of a gemcitabine solution, compared to mitomycin C, in the treatment of IR NMIBC. MaterialIn this retrospective study, patients with IR NMIBC treated between 2016 and 2020 were selected from two participating centers using either gemcitabine (center A) as the intravesical chemotherapy regimen or mitomycin C (center B). The primary endpoint was recurrence rate and secondary end points were treatment interruption and its causes. ResultsIn our cohort of 102 IR NMIBC patients, 49 patients received GMC and 53 MMC with a median follow-up of 30 months. Overall recurrence rate was 42.1% with 22.4% in the GMC group and 60.3% in the MMC group (P<0.01). This difference was also found in the multifactorial analysis. Course interruption was observed in 14.7% of all patients, primarily attributed to adverse events (46.6%), without difference between groups. ConclusionAdjuvant intravesical gemcitabine in patients with IR NMIBC seems to be an interesting option associated with a lower tumor recurrence rate and a favorable tolerance profile when compared to MMC. Larger scale prospective randomized trials are needed to validate our findings. Level of evidenceIII.

SIRT7 knockdown promotes gemcitabine sensitivity of pancreatic cancer cell via upregulation of GLUT3 expression

Gemcitabine serves as a first-line chemotherapeutic treatment for pancreatic cancer (PC), but it is prone to rapid drug resistance. Increasing the sensitivity of PC to gemcitabine has long been a focus of research. Fasting interventions may augment the effects of chemotherapy and present new options. SIRT7 is known to link metabolism with various cellular processes through post-translational modifications. We found upregulation of SIRT7 in PC cells is associated with poor prognosis and gemcitabine resistance. Cross-analysis of RNA-seq and ATAC-seq data suggested that GLUT3 might be a downstream target gene of SIRT7. Subsequent investigations demonstrated that SIRT7 directly interacts with the enhancer region of GLUT3 to desuccinylate H3K122. Our group's another study revealed that GLUT3 can transport gemcitabine in breast cancer cells. Here, we found GLUT3 KD reduces the sensitivity of PC cells to gemcitabine, and SIRT7 KD-associated gemcitabine-sensitizing could be reversed by GLUT3 KD. While fasting mimicking induced upregulation of SIRT7 expression in PC cells, knocking down SIRT7 enhanced sensitivity to gemcitabine through upregulating GLUT3 expression. We further confirmed the effect of SIRT7 deficiency on the sensitivity of gemcitabine under fasting conditions using a mouse xenograft model. In summary, our study demonstrates that SIRT7 can regulate GLUT3 expression by binding to its enhancer and altering H3K122 succinylation levels, thus affecting gemcitabine sensitivity in PC cells. Additionally, combining SIRT7 knockdown with fasting may improve the efficacy of gemcitabine. This unveils a novel mechanism by which SIRT7 influences gemcitabine sensitivity in PC and offer innovative strategies for clinical combination therapy with gemcitabine.

ZDHHC9-mediated Bip/GRP78 S-palmitoylation inhibits unfolded protein response and promotes bladder cancer progression

Recent studies have highlighted palmitoylation, a novel protein post-translational modification, as a key player in various signaling pathways that contribute to tumorigenesis and drug resistance. Despite this, its role in bladder cancer (BCa) development remains inadequately understood. In this study, ZDHHC9 emerged as a significantly upregulated oncogene in BCa. Functionally, ZDHHC9 knockdown markedly inhibited tumor proliferation, promoted tumor cell apoptosis, and enhanced the efficacy of gemcitabine (GEM) and cisplatin (CDDP). Mechanistically, SP1 was found to transcriptionally activate ZDHHC9 expression. ZDHHC9 subsequently bound to and palmitoylated the Bip protein at cysteine 420 (Cys420), thereby inhibiting the unfolded protein response (UPR). This palmitoylation at Cys420 enhanced Bip's protein stability and preserved its localization within the endoplasmic reticulum (ER). ZDHHC9 might become a novel therapeutic target for BCa and could also contribute to combination therapy with GEM and CDDP.

Curcumin synergistically enhances the efficacy of gemcitabine against gemcitabine-resistant cholangiocarcinoma via the targeting LAT2/glutamine pathway

Cholangiocarcinoma (CCA) is often diagnosed late, leading to incomplete tumor removal, drug resistance and reduced chemotherapy efficacy. Curcumin has the potential for anti-cancer activity through various therapeutic properties and can improve the efficacy of chemotherapy. We aimed to investigate the synergistic effect of a combination of curcumin and gemcitabine against CCA, targeting the LAT2/glutamine pathway. This combination synergistically suppressed proliferation in gemcitabine-resistant CCA cells (KKU-213BGemR). It also resulted in a remarkable degree of CCA cell apoptosis and cell cycle arrest, characterized by a high proportion of cells in the S and G2/M phases. Knockdown of SLC7A8 decreased the expressions of glutaminase and glutamine synthetase, resulting in inhibited cell proliferation and sensitized CCA cells to gemcitabine treatment. Moreover, in vivo experiments showed that a combination curcumin and gemcitabine significantly reduced tumor size, tumor growth rate and LAT2 expression in a gemcitabine-resistant CCA xenograft mouse model. Suppression of tumor progression in an orthotopic CCA hamster model provided strong support for clinical application. In conclusion, curcumin synergistically enhances gemcitabine efficacy against gemcitabine-resistant CCA by induction of apoptosis, partly via inhibiting LAT2/glutamine pathway. This approach may be an alternative strategy for the treatment of gemcitabine-resistant in CCA patients.

Efficacy and safety of dose-dense gemcitabine plus cisplatin as neoadjuvant chemotherapy for muscle-invasive bladder cancer.

The objective of this study was to evaluate the efficacy and safety of dose-dense gemcitabine and cisplatin (ddGC) as neoadjuvant chemotherapy for muscle-invasive bladder cancer (MIBC). Patients with locally advanced MIBC (cT2aN0M0-cT4N1M0) who received ddGC between December 2017 and December 2023 were included. Regimens of ddGC with pegfilgrastim were administered every 2 weeks for 4 cycles, followed by radical cystectomy. The pathological complete response (CR) (pT0N0) and objective response (OR) (<pT2N0) rates were evaluated in patients who underwent radical cystectomy. Tolerability was assessed using relative dose intensity (RDI). Adverse events (AEs) were documented according to the Common Terminology Criteria for Adverse Events in all patients who received ddGC. Disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method. A total of 45 patients (cT2N0, 60%; cT3N0, 22%; cT4N0, 9%; and cTanyN1, 9%) were included. Of the 41 who underwent cystectomy, 38 (92.7%) completed all planned cycles, with a median RDI of 0.96 (interquartile range [IQR], 0.89-1.00). Overall, CR and OR were achieved in 12 (29.3%) and 17 (41.5%) patients, respectively, increasing to 32.4% and 45.9%, respectively, in cN0 patients. Severe AEs (grade ≥ 3) were observed in eight patients (17.8%), including four hematological toxicities. At a median follow-up of 31 months, 2-year DFS and OS were 70.8% and 89.2%, respectively. Neoadjuvant ddGC demonstrated good tolerability, efficacy, and safety, suggesting its potential as a treatment option for MIBC.