Administration Of Gemcitabine Research Articles

The combination of gemcitabine plus an anti-FGFR inhibitor can have a synergistic antitumor effect on FGF-activating cholangiocarcinoma

Anti-FGFR treatment for cholangiocarcinoma (CCA) with fibroblast growth factor receptor (FGFR) alteration is a promising treatment option. Since the antitumor mechanisms of anti-FGFR inhibitors and conventional cytotoxic drugs differ, synergistic effects can be possible. This study aimed to evaluate the efficacy of the combined administration of gemcitabine (GEM) and pemigatinib in CCA cells with FGFR2 alterations. To simulate the treatment for patients with 3 kinds of CCA, chemonaïve CCA with activation of the FGF pathway, chemo-resistant CCA with activation of the FGF pathway, and CCA without FGF pathway activation (as controls), we evaluated 3 different CCA cell lines, CCLP-1 (with a FGFR2 fusion mutation), CCLP-GR (GEM-resistant cells established from CCLP-1), and HuCCT1 (without FGFR mutations). There was no significant difference between CCLP-1 and HuCCT1 in GEM suspensibility (IC50 = 19.3, 22.6 mg/dl, p = 0.1187), and the drug sensitivity to pemigatinib did not differ between CCLP-1 and CCLP-GR (IC50 = 7.18,7.60 nM, p = 0.3089). Interestingly, only CCLP-1 showed a synergistic effect with combination therapy consisting of GEM plus pemigatinib in vitro and in vivo. In a comparison of the reaction to GEM exposure, only CCLP-1 cells showed an increase in the activation of downstream proteins in the FGF pathway, especially FRS2 and ERK. In association with this reaction, cell cycle and mitosis were increased with GEM exposure in CCLP-1, but HuCCT1/CCLP-GR did not show this reaction. Our results suggested that combination therapy with GEM plus pemigatinib is a promising treatment for chemonaïve patients with CCA with activation of the FGF pathway.

Continuous iontronic chemotherapy reduces brain tumor growth in embryonic avian in vivo models

Local and long-lasting administration of potent chemotherapeutics is a promising therapeutic intervention to increase the efficiency of chemotherapy of hard-to-treat tumors such as the most lethal brain tumors, glioblastomas (GBM). However, despite high toxicity for GBM cells, potent chemotherapeutics such as gemcitabine (Gem) cannot be widely implemented as they do not efficiently cross the blood brain barrier (BBB). As an alternative method for continuous administration of Gem, we here operate freestanding iontronic pumps – “GemIPs” – equipped with a custom-synthesized ion exchange membrane (IEM) to treat a GBM tumor in an avian embryonic in vivo system. We compare GemIP treatment effects with a topical metronomic treatment and observe that a remarkable growth inhibition was only achieved with steady dosing via GemIPs. Daily topical drug administration (at the maximum dosage that was not lethal for the embryonic host organism) did not decrease tumor sizes, while both treatment regimes caused S-phase cell cycle arrest and apoptosis. We hypothesize that the pharmacodynamic effects generate different intratumoral drug concentration profiles for each technique, which causes this difference in outcome. We created a digital model of the experiment, which proposes a fast decay in the local drug concentration for the topical daily treatment, but a long-lasting high local concentration of Gem close to the tumor area with GemIPs. Continuous chemotherapy with iontronic devices opens new possibilities in cancer treatment: the long-lasting and highly local dosing of clinically available, potent chemotherapeutics to greatly enhance treatment efficiency without systemic side-effects. Significance statementIontronic pumps (GemIPs) provide continuous and localized administration of the chemotherapeutic gemcitabine (Gem) for treating glioblastoma in vivo. By generating high and constant drug concentrations near the vascularized growing tumor, GemIPs offer an efficient and less harmful alternative to systemic administration. Continuous GemIP dosing resulted in remarkable growth inhibition, superior to daily topical Gem application at higher doses. Our digital modelling shows the advantages of iontronic chemotherapy in overcoming limitations of burst release and transient concentration profiles, and providing precise control over dosing profiles and local distribution. This technology holds promise for future implants, could revolutionize treatment strategies, and offers a new platform for studying the influence of timing and dosing dependencies of already-established drugs in the fight against hard-to-treat tumors.

Clinical efficacy and safety of erlotinib combined with chemotherapy in the treatment of advanced pancreatic cancer: A meta-analysis.

Advanced pancreatic cancer is resistant to chemotherapeutic drugs, resulting in limited treatment efficacy and poor prognosis. Combined administration of the chemotherapeutic gemcitabine and erlotinib is considered a potential first-line treatment for advanced pancreatic cancer. However, their comparative benefits and potential risks remain unclear. To assess the clinical efficacy and safety of erlotinib combined with other chemotherapy regimens for the treatment of advanced pancreatic cancer. Literature on the clinical efficacy and safety of erlotinib combined with chemotherapy for advanced pancreatic cancer was retrieved through an online search. The retrieved literature was subjected to a methodological qualitative assessment and was analyzed using the RevMan 5.3 software. Ten randomized controlled trials involving 2444 patients with advanced pancreatic cancer were included in the meta-analysis. Compared with chemotherapeutic treatment, erlotinib combined with chemotherapy significantly prolonged the progression-free survival time of pancreatic cancer patients [hazard ratio (HR) = 0.78, 95%CI: 0.66-0.92, P = 0.003]. Meanwhile, the overall survival (HR= 0.99, 95%CI: 0.72-1.37, and P = 0.95) and disease control rate (OR = 0.93, 95%CI: 0.45-0.91, P = 0.84) were not significantly favorable. In terms of safety, the erlotinib and chemotherapy combination was associated with a significantly higher risk of diarrhea (OR = 3.59, 95%CI: 1.63-7.90, P < 0.05) and rash (OR = 3.63, 95%CI: 1.64-8.01, P < 0.05) compared with single-agent chemotherapy. Moreover, the risk of vomiting (OR = 1.27, 95%CI: 0.62-2.59, P = 0.51), regurgitation/anorexia (OR = 1.61, 95%CI: 0.25-10.31, P = 0.62), and infection (OR = 0.72, 95%CI: 0.28-1.87, P = 0.50) were not significant in either group. Compared with a single chemotherapeutic modality, erlotinib combined with gemcitabine can prolong progression-free survival in pancreatic cancer, but does not improve survival benefit or disease control rate, and can increase the risk of diarrhea and rash.

Abstract 3274: Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer

Abstract Background and Aims: Pancreatic cancer is one of the most lethal malignancies, partly due to resistance to conventional chemotherapy. The chemoresistance of malignant tumors is associated with epithelial-mesenchymal transition (EMT) and the stemness of cancer cells. The aim of this study is to investigate the availability and functional mechanisms of trefoil factor family 1 (TFF1), a tumor-suppressive protein in pancreatic carcinogenesis, to treat pancreatic cancer. Methods: To investigate the role of endogenous TFF1 in human and mice, specimens of human pancreatic cancer and genetically engineered mouse model of pancreatic cancer (KPC/TFF1KO; Pdx1-Cre/LSL-KRASG12D/LSL-p53R172H/TFF1−/−) were analyzed by immunohistochemistry (IHC). To explore the efficacy of extracellular administration of TFF1, recombinant and chemically synthesized TFF1 were administered to pancreatic cancer cell lines, a xenograft mouse model and a transgenic mouse model. Results: The deficiency of TFF1 was associated with increased EMT markers of cancer cells (Snail and Zeb1) in mouse models of pancreatic cancer, KPC. Analysis of the survival of patients who underwent chemotherapy for recurrent pancreatic cancer revealed that the expression of TFF1 in cancer cells was associated with better survival. Also, in the mouse model of pancreatic cancer, KPC mice showed improved survival when treated with gemcitabine, the KPC/TFF1KO mice did not. Pancreatic cancer cell lines were administered with gemcitabine and/or chemically synthesized TFF1, revealing that addition of TFF1 downregulated gemcitabine-induced EMT markers (Snail, Slug, ZEB1, and αSMA), Wnt pathway activation (β-catenin, TCF7, and EPHB3). In addition, TFF1 inhibited the expression of cancer stemness markers (CD133 and NANOG3) and the ability to form tumor sphere. Importantly, TFF1 accelerated the apoptosis of cancer cells induced by gemcitabine in vitro. In vivo, combined treatment of gemcitabine and subcutaneous administration of TFF1 arrested tumor growth in xenograft mouse model. Also, KPC mice with combined treatment showed the better survival rather than gemcitabine-alone treatment, with lower expression of CD133, high expression of ZEB1, and lower nuclear translocation of β-catenin. Conclusion: These results indicate that TFF1 can contribute to establishing a novel strategy to treat pancreatic cancer patients by enhancing chemosensitivity. Citation Format: Junpei Yamaguchi, Toshio Kokuryo, Yukihiro Yokoyama, Masaki Sunagawa, Taisuke Baba, Tomoki Ebata. Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3274.

Heparanase interacting BCLAF1 to promote the development and drug resistance of ICC through the PERK/eIF2α pathway.

Intrahepatic cholangiocarcinoma (ICC) is a primary epithelial carcinoma known for its aggressive nature, high metastatic potential, frequent recurrence, and poor prognosis. Heparanase (HPSE) is the only known endogenous β-glucuronidase in mammals. In addition to its well-established enzymatic roles, HPSE critically exerts non-catalytic function in tumor biology. This study herein aimed to investigate the non-enzymatic roles of HPSE as well as relevant regulatory mechanisms in ICC. Our results demonstrated that HPSE was highly expressed in ICC and promoted the proliferation of ICC cells, with elevated HPSE levels implicating a poor overall survival of ICC patients. Notably, HPSE interacted with Bcl-2-associated factor 1 (BCLAF1) to upregulate the expression of Bcl-2, which subsequently activated the PERK/eIF2α-mediated endoplasmic reticulum (ER) stress pathway to promote anti-apoptotic effect of ICC. Moreover, our in vivo experiments revealed that concomitant administration of gemcitabine and the Bcl-2 inhibitor navitoclax enhanced the sensitivity of ICC cells with highly expressed HPSE to chemotherapy. In summary, our findings revealed that HPSE promoted the development and drug resistance of ICC via its non-enzymatic function. Bcl-2 may be considered as an effective target with therapeutic potential to overcome ICC chemotherapy resistance induced by HPSE, presenting valuable insights into the development of novel therapeutic strategies against ICC.

Enhanced Anti-tumor Effect of Flavopiridol in Combination With Gemcitabine in Pancreatic Cancer.

The efficacy of current chemotherapies for pancreatic ductal adenocarcinoma (PDAC) is still unsatisfactory. Flavopiridol inhibits multiple cyclin-dependent kinases, causing cell cycle arrest and inducing cancer cell apoptosis. This study aimed to evaluate the anti-tumor effect of flavopiridol and gemcitabine in PDAC in vitro and in vivo. PANC-1 and MIA PaCa-2 cell lines were treated with gemcitabine and flavopiridol alone, in combination, and sequentially, and cell proliferation, apoptosis, and the cell cycle were evaluated. Proteins related to cell cycle progression (cyclin A, CDK2, E2F-1, and p53) were quantified using western blotting. A xenograft mouse model was generated, and the effects of gemcitabine and flavopiridol, administered alone or in combination, were evaluated by measuring tumor volume and apoptosis degree using the TUNEL assay. Sequential administration of gemcitabine and flavopiridol suppressed PDAC cell proliferation and induced apoptosis. Flavopiridol treatment led to an increase in the number of cells in the S and a decrease in those in the G0/G1 phases. Gemcitabine increased and decreased the number of S- and G2/M-phase cells, respectively. Furthermore, flavopiridol treatment decreased cyclin A and CDK2 expression and increased E2F-1 expression. In a xenograft mouse model, the combined administration of gemcitabine and flavopiridol demonstrated the most significant reduction in tumor volume and induction of apoptosis. Flavopiridol potentiates the anti-tumor activity of gemcitabine by inducing cell cycle arrest and apoptosis. Its synergistic inhibition of PDAC cell proliferation, when combined with gemcitabine, positions flavopiridol as a promising candidate for cancer treatment.

A drug delivery platform using engineered MUC1‐targeting exosomes enhances chemosensitivity and immunogenic cell death in pancreatic ductal adenocarcinoma

AbstractExosomes, a specific subset of extracellular vesicles, have diverse functions in various biological processes. In the field of cancer research, there has been a growing interest in the potential of exosomes to act as versatile vehicles for targeted tumor imaging and therapy. In this study, we constructed a targeted delivery platform using hypoimmunogenic exosomes by genetically modifying β2‐microglobulin knocking‐out HEK‐293F cells to express a fusion protein, referred to as αMUC1‐Exo, which comprises the exosomal membrane‐enriched platelet‐derived growth factor receptor, intracellular nanoluciferase, and extracellular anti‐MUC1 single‐chain variable fragment. The findings of this study indicate that αMUC1‐Exos exhibited notable drug delivery properties toward MUC1‐positive pancreatic cancer cells, resulting in a substantial inhibition of tumor growth. Moreover, these exosomes demonstrated a high level of biosafety and the absence of any adverse effects. The application of engineered exosomes as a vehicle for drug delivery holds promise for enhancing the immunogenicity of neoplastic cells following treatment, thereby inducing antitumor immune memory in mice with intact immune systems, and also improving the response to anti‐PD1 therapy. This approach utilizing engineered exosomes for Gemcitabine administration holds promise as a potential strategy for overcoming drug resistance in pancreatic carcinoma thereby improving the overall treatment efficacy.

Drug-repurposing by virtual and experimental screening of PFKFB3 inhibitors for pancreatic cancer therapy

Pancreatic cancer (PC) is the most frequently occurring cancer, with few effective treatments and a 5-year survival rate of only about 11%. It is characterized by stiff interstitium and pressure on blood vessels, leading to an increased glycolytic metabolism. PFKFB3 plays an important role in glycolysis, and its products (fructose-2,6-bisphosphate), which are allosteric PFK1 activators, limit the glycolytic rate. In this study, 14 PFKFB3 inhibitors were obtained by virtually screening the FDA-approved compound library. Subsequently, the in-vitro investigations confirmed that Lomitapide and Cabozantinib S-malate exhibit the excellent potential to inhibit PFKFB3. The combined administration of Lomitapide and Gemcitabine at a certain molar ratio indicated an enhanced anti-tumor effect in Orthotopic Pancreatic Cancer (OPC) models. This investigation provides a new treatment strategy for PC therapy.

A Phase II Study of Chidamide Plus R-GDP Salvage Chemotherapy in Relapsed/Refractory Diffuse Large B-Cell Lymphoma Ineligible for Autologous Transplantation: Efficacy and Safety Analysis

Background: A significant subset of Diffuse large B-cell lymphoma (DLBCL) patients (30%-40%) face treatment failure, necessitating effective salvage chemotherapy. We conducted a phase II study evaluating the efficacy and safety of chidamide plus R-GDP (rituximab, gemcitabine, dexamethasone, cisplatin) in relapsed/refractory (r/r) DLBCL patients. Methods: This open-label, single-arm study included 27 patients with r/r DLBCL who were ineligible for autologous stem cell transplantation. Prior to the induction monotherapy phase, chidamide was administered orally at a dose of 30 mg twice a week for one week. The combination therapy phase consisted of oral chidamide at a dose of 20 mg twice a week for two weeks, with a one-week discontinuation period, along with intravenous administration of rituximab, gemcitabine, dexamethasone, and cisplatin on a 21-day cycle. Results: A total of 27 patients received at least one dose of Chidamide plus R-GDP and were evaluated for safety. The median follow-up period was 17.0 months (range: 3.5 to 55 months). Radiological response assessment was available for 24 patients, who constituted the efficacy population. Fourteen patients completed six cycles of chidamide plus R-GDP (per-protocol population), while 10 patients discontinued treatment at the data cutoff. The baseline characteristics of enrolled patients included a median age of 67 years, predominantly older than 65 years. Approximately half of the patients exhibited elevated lactate dehydrogenase levels. All patients had received prior therapy with R-CHOP or equivalent chemoimmunotherapy. The majority of cases were classified as stage III/IV and non-germinal center B-cell-like (non-GCB) type by immunohistochemistry. Refractory or relapsed DLBCL within 1 year since the last treatment was observed in 74.0% of patients. Efficacy Outcomes: The investigator-assessed best objective response rate (ORR) was 79.2% (95% CI: 75.1% to 83.3%), with a complete response (CR) rate of 45.8% (95% CI: 41.6% to 49.9%) and a partial response (PR) rate of 33.3% (95% CI: 29.3% to 37.4%). The median time to response was 1.2 months, and the median time to CR or CRu (unconfirmed complete response) was 3.9 months. The best disease control rate was 87.5%. Among the patients who completed six cycles of chidamide plus R-GDP, the best ORR was 100%, with 71.4% achieving CR and 28.6% PR. Kaplan-Meier plots reveal that the median investigator-assessed progression-free survival (PFS) for the efficacy population was 5.9 (95% CI, 3.1 to 12.4) months. The median overall survival was 48.3 (95% CI, 13.1 to not reach (NR)) months. Safety Outcomes: A total of 13 patients (48.1%) required treatment interruption, primarily due to adverse events (22.2%) and disease progression (18.5%). Among patients who completed six cycles of chidamide plus R-GDP, 57.1% required a chidamide dose reduction. The most frequent treatment-emergent adverse event was anemia, occurring in all patients. Thrombocytopenia was the most common grade ≥3 adverse event leading to treatment interruption or dose reduction, affecting 48.1% of patients. Non-hematologic events included hypocalcemia (59.3%), hyponatremia (55.6%), and hypokalemia (44.4%). Three patients experienced grade 3 pneumonitis, and one patient had grade 3 skin rash. Conclusion: Chidamide plus R-GDP salvage chemotherapy demonstrated promising efficacy (ORR: 79.2%; CR rate: 45.8%) in r/r DLBCL patients. Adverse events were manageable but necessitated monitoring. Larger trials are needed to validate these findings and establish chidamide plus R-GDP as a potential treatment option for this challenging population. Keywords: relapsed/refractory DLBCL, salvage chemotherapy, chidamide, R-GDP, efficacy, safety

SIRT3-dependent mitochondrial redox homeostasis mitigates CHK1 inhibition combined with gemcitabine treatment induced cardiotoxicity in hiPSC-CMs and mice.

Administration of CHK1-targeted anticancer therapies is associated with an increased cumulative risk of cardiac complications, which is further amplified when combined with gemcitabine. However, the underlying mechanisms remain elusive. In this study, we generated hiPSC-CMs and murine models to elucidate the mechanisms underlying CHK1 inhibition combined with gemcitabine-induced cardiotoxicity and identify potential targets for cardioprotection. Mice were intraperitoneally injected with 25mg/kg CHK1 inhibitor AZD7762 and 20mg/kg gemcitabine for 3weeks. hiPSC-CMs and NMCMs were incubated with 0.5uM AZD7762 and 0.1uM gemcitabine for 24h. Both pharmacological inhibition or genetic deletion of CHK1 and administration of gemcitabine induced mtROS overproduction and pyroptosis in cardiomyocytes by disrupting mitochondrial respiration, ultimately causing heart atrophy and cardiac dysfunction in mice. These toxic effects were further exacerbated with combination administration. Using mitochondria-targeting sequence-directed vectors to overexpress CHK1 in cardiomyocyte (CM) mitochondria, we identified the localization of CHK1 in CM mitochondria and its crucial role in maintaining mitochondrial redox homeostasis for the first time. Mitochondrial CHK1 function loss mediated the cardiotoxicity induced by AZD7762 and CHK1-knockout. Mechanistically, mitochondrial CHK1 directly phosphorylates SIRT3 and promotes its expression within mitochondria. On the contrary, both AZD7762 or CHK1-knockout and gemcitabine decreased mitochondrial SIRT3 abundance, thus resulting in respiration dysfunction. Further hiPSC-CMs and mice experiments demonstrated that SIRT3 overexpression maintained mitochondrial function while alleviating CM pyroptosis, and thereby improving mice cardiac function. In summary, our results suggest that targeting SIRT3 could represent a novel therapeutic approach for clinical prevention and treatment of cardiotoxicity induced by CHK1 inhibition and gemcitabine.

Early Assessment of Radiation Treatment at Clinical Field Strength by D2O Administration and Deuterium MRI

An accurate and non-invasive assessment of tumor response following treatment is essential. Traditional anatomical imaging techniques are insufficient before a significant morphological change can be observed. Metabolic imaging of molecular processes in the living body is also used. In recent years, deuterium magnetic resonance spectroscopic (MRS) imaging has been demonstrated as an alternative for cancer metabolic imaging by high-field (4-11T) MRI using deuterium-labeled molecules as a contrast agent. The study aim was to evaluate the feasibility of using deuterium MRI 1.5T for tumor visualization and early assessment of the efficacy of three anticancer treatment strategies (radiation and anticancer drugs) in pancreatic cancer model mice given heavy water (D2O) to induce deuterium (2H)-tissue labeling. A MIA PaCa-2 pancreatic cancer model of six BALB/c-nu mice was prepared, and repeated deuterium MRI was performed during the first 10 days after starting free drinking of 30% D2O. We also evaluated 2H accumulation in the tumor after irradiation, bevacizumab administration, or gemcitabine administration of other 20 mice. Additional confirmatory proton MRI, ex vivo metabolic hyperpolarization 13C-MRS and histopathology were performed. The mouse's whole-body distribution of 2H was visible 1 day after drinking, and the signal intensity increased daily. Although the tumor size did not change 1 and 3 days after irradiation, the amount of 2H in the tumor decreased significantly. The 2H image intensity of the tumor also significantly decreased after the administration of bevacizumab or gemcitabine. Metabolic hyperpolarization 13C-MRS, proton MRI and 2H-NMR spectroscopy confirmed the efficacy of the anticancer treatments. Deuterium MRI at 1.5T proved feasibility to track 2H distribution throughout mouse tissues during D2O administration and revealed a higher 2H accumulation in the tumor xenografts. This research demonstrated a promising successful method for early assessment of radiotherapy and chemotherapy of pancreatic cancer.

Deuterium Magnetic Resonance Imaging Using Deuterated Water-Induced 2H-Tissue Labeling Allows Monitoring Cancer Treatment at Clinical Field Strength.

An accurate and noninvasive assessment of tumor response following treatment other than traditional anatomical imaging techniques is essential. Deuterium magnetic resonance spectroscopic (MRS) imaging has been demonstrated as an alternative for cancer metabolic imaging by high-field MRI using deuterium-labeled molecules. The study aim was to use 2H tissue labeling and deuterium MRI at clinical field strength for tumor visualization and assessment of three anticancer therapies in pancreatic cancer model mice. MIA PaCa-2 pancreatic carcinoma and C26 colorectal carcinoma models of BALB/c-nu mice was prepared, and repeated deuterium MRI was performed during the first 10 days of free drinking of 30% D2O to track 2H distribution in tissues. 2H accumulation in the tumor after irradiation, bevacizumab administration, or gemcitabine administration was also measured in MIA PaCa-2-bearing mice. Confirmatory proton MRI, ex vivo metabolic hyperpolarization 13C-MRS, and histopathology were performed. The mouse's whole-body distribution of 2H was visible 1 day after drinking, and the signal intensity increased daily. Although the tumor size did not change 1 and 3 days after irradiation, the amount of 2H decreased significantly. The 2H image intensity of the tumor also significantly decreased after the administration of bevacizumab or gemcitabine. Metabolic hyperpolarization 13C-MRS, proton MRI, and 2H-NMR spectroscopy confirmed the efficacy of the anticancer treatments. Deuterium MRI at 1.5T proved feasible to track 2H distribution throughout mouse tissues during D2O administration and revealed a higher 2H accumulation in the tumor xenografts. This research demonstrated a promising successful method for preliminary assessment of radiotherapy and chemotherapy of cancer.

Unveiling a Rare Complication: Gemcitabine-Induced Cardiomyopathy in Ovarian Serous Adenocarcinoma

Gemcitabine is a nucleoside analogue and pyrimidine antimetabolite authorized for the treatment of ovarian cancer. It is generally considered safe and well-tolerated, with only a few reported cases of cardiac adverse effects. However, we present a case of gemcitabine-induced dilated cardiomyopathy in a 33-year-old female receiving gemcitabine as second-line therapy for ovarian serous adenocarcinoma. The patient had no history of hypertension or significant cardiac issues. She presented with clinical symptoms, laboratory abnormalities, and imaging findings consistent with congestive cardiac failure, along with a Left Ventricular Ejection Fraction (LVEF) of 25-30%. Gemcitabine administration was immediately discontinued, and treatment with Furosemide, ACE inhibitors, and Beta-blocker agents was initiated. Subsequently, the patient’s condition improved, with the resolution of symptoms and normalization of cardiac findings upon discontinuation of gemcitabine. This is the first reported case demonstrating objective evidence of gemcitabine-induced dilated cardiomyopathy in a patient with ovarian serous adenocarcinoma without a significant cardiac history. Although rare, it is crucial to promptly diagnose gemcitabine-induced cardiomyopathy to initiate appropriate management protocols.

Gemcitabine effects on tumor microenvironment of pancreatic ductal adenocarcinoma: Special focus on resistance mechanisms and metronomic therapies

Pancreatic ductal adenocarcinoma (PDAC) is considered one of the deadliest malignancies, with dismal survival rates and extremely prevalent chemoresistance. Gemcitabine is one of the primary treatments used in treating PDACs, but its benefits are limited due to chemoresistance, which could be attributed to interactions between the tumor microenvironment (TME) and intracellular processes. In preclinical models, certain schedules of administration of gemcitabine modulate the TME in a manner that does not promote resistance. Metronomic therapy constitutes a promising strategy to overcome some barriers associated with current PDAC treatments. This review will focus on gemcitabine's mechanism in treating PDAC, combination therapies, gemcitabine's interactions with the TME, and gemcitabine in metronomic therapies.

Comprehensive analysis identifies novel targets of gemcitabine to improve chemotherapy treatment strategies for colorectal cancer.

Gemcitabine (GEM) is a second-line anticancer drug of choice for some colorectal cancer (CRC) patients, and GEM inability to be commonly available in the clinic due to the lack of clarity of the exact action targets. The half maximal inhibitory concentration (IC50) of GEM treatment for 42 CRC cell lines were accessed from the Genomics of Drug sensitivity in Cancer (GDSC) database. High-throughput sequencing data of CRC patients were captured in The Cancer Genome Atlas (TCGA) and Weighted correlation network analysis (WGCNA) was conducted. Pearson correlations were derived for GEM potency-related genes. Differential analysis was conducted in the TCGA cohort to obtain CRC development-related genes (CDRGs), and univariate COX model analysis was performed on CDRGs overlapping with GEM potency-related genes to obtain CDRGs affecting CRC prognosis. Hub genes affecting GEM potency were identified by Spearman correlation. CALB2 and GPX3 were identified as potential targets for GEM treatment of CRC via prognostic analysis, which we also observed to be elevated with elevated clinical stage in CRC patients. The enhanced expression of CALB2 and GPX3 genes identified in the pathway analysis might inhibit the body metabolism as well as activate immune and inflammation related pathways. In addition, we found that CALB2 and GPX3 could also be considered as prognostic biomarkers in pan-cancer. Finally, we found that CALB2 and GPX3 were remarkably associated with the drug sensitivity of MG-132, Dasatinib, Shikonin, Midostaurin, MS-275, and Z-LNle-CHO, which were expected to be the drugs of choice for GEM combination. CALB2 and GPX3 represent prognostic biomarkers for CRC and they might be potential action targets for GEM. Our study offered innovative ideas for GEM administration strategies.

Gemcitabine plus nab-paclitaxel for pancreatic cancer and interstitial lung disease: A nationwide longitudinal study.

Interstitial lung disease (ILD) is an adverse event associated with gemcitabine administration. Gemcitabine plus nab-paclitaxel, which is now a first-line chemotherapy regimen for pancreatic cancer (PC), may increase the risk of ILD; however, large-scale clinical data on this are limited. Thus, this study aimed to elucidate the incidence and risk factors of ILD in patients with PC receiving gemcitabine plus nab-paclitaxel. Through the Diagnosis Procedure Combination database, a Japanese nationwide inpatient database with outpatient data, we identified consecutive patients with PC who received gemcitabine-based chemotherapy between July 2010 and March 2019 at 205 hospitals. Competing-risk analysis was used to examine the cumulative incidence and risk factors of ILD. Among the 6163 patients who received gemcitabine plus nab-paclitaxel, we documented 168 patients (2.7%) who developed ILD with cumulative incidence rates (95% confidence intervals [CIs]) of 2.0% (1.6%-2.4%), 2.7% (2.2%-3.1%), and 3.1% (2.6%-3.6%) at 3, 6, and 12 months, respectively. Compared with patients with PC who received gemcitabine monotherapy, those who received gemcitabine plus nab-paclitaxel had an adjusted subdistribution hazard ratio (SHR) for ILD of 1.93 (95% CI: 1.51-2.47). Older age was associated with a high risk of ILD in patients receiving gemcitabine plus nab-paclitaxel (adjusted SHR comparing ≥75 to ≤74 years, 1.61; 95% CI: 1.16-2.24). In conclusion, this study demonstrated the clinical course of gemcitabine plus nab-paclitaxel-associated ILD in patients with PC. When gemcitabine plus nab-paclitaxel is administered to elderly patients with PC, symptoms associated with ILD must be monitored.

Thymoquinone affects the gemcitabine sensitivity of pancreatic cancer by regulating collagen via hypoxia inducible factor-1α.

Objective: To clarify the potential therapeutic effects of thymoquinone (TQ) on pancreatic cancer and its gemcitabine (GEM) sensitivity. Methods: The expression levels of hypoxia inducible factor-1α (HIF-1α), collagens (COL1A1, COL3A1, and COL5A1), and transforming growth factor-β1 (TGFβ1) in pancreatic cancer and para-carcinoma tissues were compared using immunohistochemical methods, and their relationships with TNM staging were analyzed. The effects of TQ on apoptosis, migration, invasion, and GEM sensitivity of pancreatic cancer cells were assessed using in vitro and in vivo experiments. Western blot and immunohistochemistry were used to detect the expression levels of HIF-1α, extracellular matrix (ECM) production pathway-related proteins, and TGFβ/Smad signaling pathway-related proteins. Results: The expression levels of HIF-1α, COL1A1, COL3A1, COL5A1, and TGFβ1 in pancreatic cancer tissues were significantly higher than those in para-carcinoma tissues and correlated with TNM staging (p < 0.05). TQ and GEM administration inhibited the migration and invasion of the human pancreatic cancer cell line PANC-1 and promoted the apoptosis of PANC-1 cells. The combination of TQ and GEM was more effective than GEM alone. Western blot analysis showed that the expression levels of HIF-1α, ECM production pathway-related proteins, and TGFβ/Smad signaling pathway-related proteins were significantly decreased when TQ was used to treat PANC-1 cells (p < 0.05), and the expression levels of these proteins in the TQ + GEM group were significantly more decreased than those in the GEM group. Overexpression or knockdown of HIF-1α in PANC-1 cells showed the same effects as those induced by TQ administration. In vivo experiments showed that in PANC-1 tumor-bearing mice, tumor volume and tumor weight in mice treated with GEM and TQ were significantly lower than those in control or GEM-treated mice, whereas cell apoptosis was significantly increased (p < 0.05). Western blot and immunohistochemistry results showed that the levels of HIF-1α, ECM production pathway-related proteins, and TGFβ/Smad signaling pathway-related proteins in the GEM + TQ treatment group were further decreased compared to the control group or the GEM treatment group (p < 0.05). Conclusion: In pancreatic cancer cells, TQ can promote apoptosis, inhibit migration, invasion, and metastasis, and enhance the sensitivity to GEM. The underlying mechanism may involve the regulation of ECM production through the TGFβ/Smad pathway, in which HIF-1α plays a key role.

Abstract 3998: Metronomic gemcitabine plus neratinib effectively inhibits the growth of human Her-2 positive breast cancer cells intracranially implanted into immunodeficient mice

Abstract Metastatic breast cancer is a major cause of death for women in the US, and breast cancers that metastasize to the brain have a particularly poor prognosis. To treat brain metastases of Her-2 positive breast cancers a number of Her-2 targeting drugs are now clinically available, including lapatinib, neratinib and tucatinib, among others. However, in part as a consequence of poor penetration of many drugs into the brain, combinations of standard chemotherapy plus targeted agent have only modest impact on progression free survival for such patients. We have developed preclinical models of human Her-2 positive breast cancer brain metastases to help address these issues. We selected human MDA-MD-361 and BT474 breast cancer cells lines by in vivo passaging in SCID mice, followed by molecular tagging of the derived variants (MDA361R and BT474R respectively), and then the stereotactic implantation of such cells into the brain of female SCID mice. Using luciferase-tagged BT474R we implanted 75,000 cells into the brains of the mice, and thereafter confirmed by luminescence the growth of the cells, which allowed for randomization of the mice to receive control saline (n=7), metronomic gemcitabine (100mg/kg/3days; i.p.; n=8), neratinib (40mg/kg/3 days; p.o.; n=7), or the combination of gemcitabine plus neratinib (n=8), which continued for 5 months largely in the absence of overt toxicity. The gemcitabine plus neratinib combination prolonged survival over the controls (150 days vs 65 days, p&amp;lt;0.5), although eventually all mice succumbed to disease. Tumors cells have been isolated from these therapy-administered mice for further characterization. Neratinib alone did not result in an increase in survival compared to controls, whereas metronomic gemcitabine improved survival but was inferior to the combination. We confirmed these findings using MDA361R tagged with human chorionic gonadotropin (hCG), which allows for the growth of cells to be monitored by assessment of hCG in the mouse urine, and these cells were implanted intracranially into female SCID mice. After urine hCG levels confirmed the presence of growing cells in the brain, the mice were randomized to the above 4 therapies (n=4/group), which showed an increase in survival of the combination compared to controls. These results point to intriguing effects of chemotherapy when used at continuous low (metronomic) doses, that in these studies involved gemcitabine administration every 3 days, and which in these models can be effectively combined with neratinib to suppress the growth of Her-2 positive breast cancer cells implanted into the mouse brain. These results highlight promising combination that could be used to suppress Her-2 positive breast cancer brain metastatic growth, and the developed models should facilitate the study of this subset of breast cancers. Citation Format: Serina Batson, Alejandro Sanchez, Hector M. Padilla, Diana L. Prospero, Brenda Lugo, Valeria V. Lopez, Daniella E. Estrada, Nydia De Avila, Saeedeh Darvishi, Arlene Levario, Shan Man, Ping Xu, Robert S. Kerbel, Guido Bocci, Giulio Francia. Metronomic gemcitabine plus neratinib effectively inhibits the growth of human Her-2 positive breast cancer cells intracranially implanted into immunodeficient mice. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3998.

Abstract 4801: Laurine acid enhances GEM-chemosensitivity targeting hypoxia-induced mitochondrial disfunction and stemness in pancreatic ductal adenocarcinoma

Abstract Hypoxia is a feature of the pancreatic ductal adenocarcinoma (PDA). Although gemcitabine (GEM) is widely used in chemotherapy for PDA, drug resistance restricts its clinical effectiveness. We have found that hypoxia contributes to chemoresistance, however the mechanism is still unclear. The aim of this study is to clarify the mechanism and to develop a new therapeutic strategy. First, we examined the effect of hypoxia to GEM sensitivity, stemness and energy metabolism in three human pancreatic ductal carcinoma cell lines. The inhibition rate by GEM was lower under CoCl2-induced chemical hypoxia than normoxia. Reactive oxygen species (ROS) after GEM was increased under normoxia but not under hypoxia. Flux analysis showed that both oxidative phosphorylation (OXPHOS) and glycolysis were suppressed under hypoxia, indicating a quiescent state. Next, we investigated the relationship between hypoxia and stemness. Hypoxia increased stem cell markers mRNA (C-Myc, Oct-3/4, CD24, CD44, CD133) expression and tumorsphere formation efficiency (TFE). In addition, hypoxia and GEM administration reduced sphere size but increased the number of spheres and TFE. This indicated that hypoxia and GEM suppressed proliferation, however promoted stemness. Second, to examine the mechanism of GEM resistance, we established two GEM-resistant cell lines from human PDA cells by continuous treatment with GEM and CoCl2-induced chemical hypoxia. One resistant cell line possessed reduced OXPHOS and decreased mitochondrial ROS levels, while the other resistant cell line possessed increased stemness. In both cell lines, ethidium bromide-stained mitochondrial DNA levels decreased, suggesting mitochondrial DNA damage. In addition, tetramethylrhodamine-stained mitochondrial membrane potential levels decreased, suggesting mitochondrial impairment. This indicated that long hypoxia and treatment with GEM induced mitochondrial impairment and acquisition of stemness, causing chemoresistance. We further investigated the effect of lauric acid (LAA), a medium-chain fatty acid, on GEM resistance. We have previously reported that LAA causes reprogramming of energy metabolism and induces cell death in cancer cells. Treatment with LAA restored GEM sensitivity in both GEM-resistant cell lines. Flux analysis showed that both OXPHOS and glycolysis were promoted, indicating displacement from quiescent state by LAA. These results suggest that decreased energy production, decreased mitochondrial ROS levels, and increased stemness associated with mitochondrial damage caused by GEM lead to GEM resistance, and that hypoxia may promote this process. Furthermore, forced activation of OXPHOS by LAA could be a tool to overcome GEM resistance. Citation Format: Tadataka Takagi, Hiroki Kuniyasu, Masayuki Sho, Rina Tani, Shiori Mori, Shingo Kishi, Yukiko Nishiguchi, Yudai Hojo. Laurine acid enhances GEM-chemosensitivity targeting hypoxia-induced mitochondrial disfunction and stemness in pancreatic ductal adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4801.

Abstract A015: Rationale for the use of pulsed rather than continual dosing of the novel Focal Adhesion Kinase inhibitor AMP945 in pancreatic cancer

Abstract Amplia Therapeutics Limited is developing AMP945, a highly selective inhibitor of Focal adhesion kinase (FAK) for the treatment of pancreatic cancer in combination with standard of care gemcitabine and nab-paclitaxel.1 FAK has been associated with the activity of myofibroblasts and collagen deposition and remodeling in PDAC. In preclinical studies, AMP945 displays potent anti-fibrotic activity in vitro and in vivo. In mouse models of PDAC, pulsed dosing of AMP945 added to gemcitabine and nab-paclitaxel inhibited collagen deposition and cross-linking and potentiated the effect of chemotherapy leading to increased survival.2A Phase 1 trial of AMP945 has been completed in which AMP945 showed excellent safety, tolerability, and pharmacokinetic properties as well as pharmacodynamic evidence of target engagement. Amplia’s recently initiated Phase 1b/2a clinical trial AMP945-PC-2013 (ACCENT) will assess a pulse dosing regimen of AMP945 in combination with gemcitabine and nab-paclitaxel as first-line therapy in patients with advanced pancreatic cancer. In ACCENT, patients will undergo a one-week oral loading dose of AMP945 and will be pulse dosed for four days prior to IV administration of gemcitabine and nab-paclitaxel, given according to a standard treatment schedule. Once daily oral dosing has anticipated benefits in terms of limitation of risk of acquired resistance, minimal potential for drug-drug interactions, adherence to therapy, and allows patients to self-administer AMP945 with the aim of potentiating response to standard of care chemotherapy. This abstract presentation will report on AMP945’s development status and the clinical rationale and status of the ACCENT trial. 1. Von Hoff et al., N Engl J Med 2013; 369:1691-1703 2. Murphy KJ et al. Sci Adv. 2021 Oct;7(40):eabh0363. 3. https://clinicaltrials.gov/ct2/show/NCT05355298 Citation Format: John Lambert, Mark Devine, Anthony Bishop. Rationale for the use of pulsed rather than continual dosing of the novel Focal Adhesion Kinase inhibitor AMP945 in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A015.