Comparative analysis of recurrence rates between intravesical gemcitabine and bacillus Calmette-Guérin induction therapy following transurethral resection of bladder tumors in patients with intermediate- and high-risk bladder cancer: A retrospective multicenter study.

PURPOSE: This study investigated the efficacy of intravesical gemcitabine as an alternative to bacillus Calmette-Guérin (BCG) therapy. MATERIALS AND METHODS: Data were retrospectively collected across seven institutions from February 1999 to May 2023. Inclusion criteria included patients with intermediate- or high-risk non-muscle invasive bladder cancer (NMIBC) who underwent transurethral resection of bladder tumors (TURBT) and received at least four sessions of intravesical gemcitabine or BCG induction therapy. Patient characteristics, complete remission (CR), occurrence, and progression rates were compared. RESULTS: In total, 149 patients were included in this study (gemcitabine, 63; BCG, 86). No differences were apparent between the two groups in baseline characteristics, except for the follow-up period (gemcitabine, 9.2±5.9 months vs. BCG, 43.9±41.4 months, p<0.001). There were no consistent significant differences observed between the two groups in the 3-month (gemcitabine, 98.4% vs. BCG, 95.3%; p=0.848), 6-month (94.9% vs. 90.0%, respectively; p=0.793) and 1-year CR rates (84.2% vs. 83.3%, respectively; p=0.950). Also, there was no significant statistical difference in progression-free survival between the two groups (p=0.953). The occurrence rates of adverse events were similar between the groups (22.2% vs. 22.1%; p=0.989); however, the rate of Clavien-Dindo grade 2 or higher was significantly higher in the BCG group (1.6% vs. 16.3%, respectively; p<0.001). CONCLUSIONS: Intravesical gemcitabine demonstrated efficacy comparable to BCG therapy for the first year in patients with intermediate- and high-risk NMIBC. However, long-term follow-up studies are warranted.

Effect of immune-modulating metronomic capecitabine as an adjuvant therapy in locoregionally advanced nasopharyngeal carcinoma.

INTRODUCTION: Metronomic capecitabine used as an adjuvant therapy improves survival in patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC). This therapeutic approach may also contribute to improving immune function, consequently enhancing overall therapeutic efficacy. AIM: We aimed to evaluate the effect of metronomic capecitabine as adjuvant therapy on immune function and survival in cases of LA-NPC. SUBJECTS AND METHODS: 28 patients with LA-NPC were enrolled in the study and equally assigned to two groups of 14 each: experimental and control group. The experimental group received induction chemotherapy + concurrent chemotherapy + adjuvant chemotherapy as well as oral capecitabine at a dose of 650 mg/m² of body surface area twice daily for 1 year, with the option to discontinue in case of intolerance. The control group did not receive additional chemotherapy or targeted drugs after the induction chemotherapy + concurrent chemoradiotherapy; however, they were followed up regularly. Changes in immune function and survival were compared between the two groups. RESULTS: The median follow-up time was 43.5 months. One year after adjuvant chemotherapy, the experimental group showed higher levels of CD8 + cells, CD28 + CD8 + cells, and activated CD8 + cells compared to the control group (P < 0.05). The CD4/CD8 ratio and proportion of monocyte-derived dendritic cells were also higher in the experimental group than in the control group, but the difference was not statistically significant (P ≥ 0.05). Comparisons of 3-year overall survival, local-regional recurrence-free survival, progression-free survival, and distant metastasis-free survival between the two groups showed percentages of 92.9% vs. 78.6%, 92.9% vs. 92.9%, 78.6% vs. 71.4%, and 85.7% vs. 0.78 0.6% respectively, but these differences were not significant (P > 0 0.05 ). CONCLUSION: Metronomic capecitabine chemotherapy was observed to induce an immunomodulatory effect in LA-NPC. TRIAL REGISTRATION: NCT02958111, date of registration 04-11-2016.

Oral azacitidine compared with standard therapy in patients with relapsed or refractory follicular helper T-cell lymphoma (ORACLE): an open-label randomised, phase 3 study.

BACKGROUND: Follicular helper T-cell lymphomas (TFHL) harbour frequent alterations in genes that regulate DNA methylation. Preliminary reports suggest that treatment with 5-azacitidine has clinical activity in patients with relapsed or refractory TFHL. We aimed to compare the oral form of azacitidine with investigator's choice standard therapy (ICT; ie, gemcitabine, bendamustine, or romidepsin) in patients with relapsed or refractory TFHL. METHODS: Patients older than 18 years with relapsed or refractory TFHL (angioimmunoblastic T-cell lymphoma, follicular lymphoma, or nodal T-cell lymphoma with phenotype, ie, positive with two or more markers among CD10, BCL6, CXCL13, PD1, or ICOS) based on the 2017 WHO classification of haematological neoplasms, with an Eastern Cooperative Oncology Group performance status score of 0-3, were recruited in university hospitals from five European countries and from Japan. Patients were randomly assigned 1:1 to treatment with either azacitidine given at a dose of 300 mg once a day (200 mg in Japanese patients) for 14 days in a 28-day cycle or gemcitabine, bendamustine, or romidepsin according to the investigator's choice. Random assignment was stratified by the number of previous lines of therapy and by the presence of previous or concomitant myeloid malignancy. The primary endpoint was investigator-assessed progression-free survival, presented in the intention-to-treat population. This Article is the final analysis of this trial, registered at ClinicalTrials.gov (Europe NCT03593018 and Japan NCT03703375). FINDINGS: 86 patients (median age 69 years [IQR 62-76], 50 patients were male, 36 were female) were enrolled between Nov 9, 2018, to Feb 22, 2021; 42 in the azacitidine group and 44 in the ICT group. With a median follow-up of 27·4 months (IQR 20·2-32·9), the median progression-free survival was 5·6 months (95% CI 2·7 -8·1) in the azacitidine group versus 2·8 months (1·9-4·8) in the ICT group (hazard ratio of 0·63 (95% CI 0·38-1·07); 1-sided p=0·042). Grade 3-4 adverse events were reported in 32 (76%) of 42 patients in the azacitidine group versus 42 (98%) of 43 patients in the ICT group. The most adverse grade 3 or worse adverse events were haematological (28 [67%] of 42 patients vs 40 [93%] of 43 patients), infection (8 [19%] and 14 [33%]), and gastrointestinal (5 [12%] vs 1 [2%] for azacitidine and ICT, respectively). There were two treatment-related deaths in the azacitidine group (one endocarditis and one candidiasis) and three in the ICT group (one heart failure, one COVID-19, and one cause unknown). INTERPRETATION: Although the pre-specified primary outcome of the trial was not met, the favourable safety profile suggests that azacitidine could add to the treatment options in these difficult to treat diseases especially in combination with other drugs. Trials with combination are in preparation in a platform trial. FUNDING: Bristol-Myers Squibb. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

The double life of a chemotherapy drug: Immunomodulatory functions of gemcitabine in cancer.

Although the development of immunotherapies has been revolutionary in the treatment of several cancers, many cancer types remain unresponsive to immune-based treatment and are largely managed by chemotherapy drugs. However, chemotherapeutics are not infallible and are frequently rendered ineffective as resistance develops from prolonged exposure. Recent investigations have indicated that some chemotherapy drugs have additional functions beyond their normative cytotoxic capacity and are in fact immune-modifying agents. Of the pharmaceuticals with identified immune-editing properties, gemcitabine is well-studied and of interest to clinicians and scientists alike. Gemcitabine is a chemotherapy drug approved for the treatment of multiple cancers, including breast, lung, pancreatic, and ovarian. Because of its broad applications, relatively low toxicity profile, and history as a favorable combinatory partner, there is promise in the recharacterization of gemcitabine in the context of the immune system. Such efforts may allow the identification of suitable immunotherapeutic combinations, wherein gemcitabine can be used as a priming agent to improve immunotherapy efficacy in traditionally insensitive cancers. This review looks to highlight documented immunomodulatory abilities of one of the most well-known chemotherapy agents, gemcitabine, relating to its influence on cells and proteins of the immune system.

Assessing outcomes of topical 5-fluorouracil as primary and adjuvant therapy for squamous cell carcinoma in-situ.

Cutaneous squamous cell carcinoma in-situ (SCCis) is an intraepithelial tumor with a good prognosis. Standard treatment includes both surgical and non-surgical interventions. We determined the clearance rate for SCCis and residual SCCis identified on frozen section during Mohs micrographic surgery (MMS) after treatment with topical fluorouracil 5% cream (5-FU). All MMS cases were initiated for biopsy-proven invasive squamous cell carcinoma (SCC). A retrospective chart review was conducted from January 2017-February 2024 at Columbia University Irving Medical Center (CUIMC) to identify patients with SCCis who were treated with topical 5-FU as primary therapy or adjuvant therapy (AT) for residual SCCis post-MMS for invasive SCC. 41 patients were included (80% males, 70.1 ± 11.8 years). The average follow-up time for the primary therapy group was 25.4 ± 12.8 months, and for the post-MMS AT group 22.5 ± 11.1 months. In the group treated with topical 5-FU as primary therapy (n = 28), 27 patients (96.43%, 95% confidence interval: 81.65-99.91%) achieved complete clearance. One patient had recurrence at 8 months post-treatment. Of the patients in the post-MMS adjuvant treatment group (n = 13), 12 (92.3% clearance, 95% confidence interval 63.97-99.81%) achieved complete clearance. One patient had recurrence at 8 months post-treatment. This study found that topical 5-FU cream is effective as both primary therapy for SCCis and as adjuvant therapy for residual SCCis following MMS of invasive SCC.

WNT3 promotes chemoresistance to 5-Fluorouracil in oral squamous cell carcinoma via activating the canonical ß-catenin pathway.

BACKGROUND: 5-Fluorouracil (5FU) is a primary chemotherapeutic agent used to treat oral squamous cell carcinoma (OSCC). However, the development of drug resistance has significantly limited its clinical application. Therefore, there is an urgent need to determine the mechanisms underlying drug resistance and identify effective targets. In recent years, the Wingless and Int-1 (WNT) signaling pathway has been increasingly studied in cancer drug resistance; however, the role of WNT3, a ligand of the canonical WNT signaling pathway, in OSCC 5FU-resistance is not clear. This study delved into this potential connection. METHODS: 5FU-resistant cell lines were established by gradually elevating the drug concentration in the culture medium. Differential gene expressions between parental and resistant cells underwent RNA sequencing analysis, which was then substantiated via Real-time quantitative PCR (RT-qPCR) and western blot tests. The influence of the WNT signaling on OSCC chemoresistance was ascertained through WNT3 knockdown or overexpression. The WNT inhibitor methyl 3-benzoate (MSAB) was probed for its capacity to boost 5FU efficacy. RESULTS: In this study, the WNT/ß-catenin signaling pathway was notably activated in 5FU-resistant OSCC cell lines, which was confirmed through transcriptome sequencing analysis, RT-qPCR, and western blot verification. Additionally, the key ligand responsible for pathway activation, WNT3, was identified. By knocking down WNT3 in resistant cells or overexpressing WNT3 in parental cells, we found that WNT3 promoted 5FU-resistance in OSCC. In addition, the WNT inhibitor MSAB reversed 5FU-resistance in OSCC cells. CONCLUSIONS: These data underscored the activation of the WNT/ß-catenin signaling pathway in resistant cells and identified the promoting effect of WNT3 upregulation on 5FU-resistance in oral squamous carcinoma. This may provide a new therapeutic strategy for reversing 5FU-resistance in OSCC cells.

Pharmacogenomics, Race, and Treatment Outcome in Pediatric Acute Myeloid Leukemia.

Importance: Disparities in outcomes exist between Black and White patients with acute myeloid leukemia (AML), with Black patients experiencing poorer prognosis compared with their White counterparts. Objective: To assess whether varying intensity of induction therapy to treat pediatric AML is associated with reduced disparities in treatment outcome by race. Design, Setting, and Participants: A comparative effectiveness analysis was conducted of 86 Black and 359 White patients with newly diagnosed AML who were enrolled in the AML02 trial from 2002 to 2008 or the AML08 trial from 2008 to 2017. Statistical analysis was conducted from July 2023 through January 2024. Interventions: Patients in AML02 were randomly assigned to receive standard low-dose cytarabine-based induction therapy or augmented high-dose cytarabine-based induction therapy, whereas patients in AML08 received high-dose cytarabine-based therapy. Main Outcomes and Measures: Cytarabine pharmacogenomic 10-single-nucleotide variant (ACS10) scores were evaluated for association with outcome according to race and treatment arm. Results: This analysis included 86 Black patients (mean [SD] age, 8.8 [6.5] years; 54 boys [62.8%]; mean [SD] leukocyte count, 52 600 [74 000] cells/µL) and 359 White patients (mean [SD] age, 9.1 [6.2] years; 189 boys [52.6%]; mean [SD] leukocyte count, 54 500 [91 800] cells/µL); 70 individuals with other or unknown racial and ethnic backgrounds were not included. Among all patients without core binding factor AML who received standard induction therapy, Black patients had significantly worse outcomes compared with White patients (5-year event-free survival rate, 25% [95% CI, 9%-67%] compared with 56% [95% CI, 46%-70%]; P = .03). By contrast, among all patients who received augmented induction therapy, there were no differences in outcome according to race (5-year event-free survival rate, Black patients, 50% [95% CI, 38%-67%]; White patients, 48% [95% CI, 42%-55%]; P = .78). Among patients who received standard induction therapy, those with low ACS10 scores had a significantly worse 5-year event-free survival rate compared with those with high scores (42.4% [95% CI, 25.6%-59.3%] and 70.0% [95% CI, 56.6%-83.1%]; P = .004); however, among patients who received augmented induction therapy, there were no differences in 5-year event-free survival rates according to ACS10 score (low score, 60.6% [95% CI, 50.9%-70.2%] and high score, 54.8% [95% CI, 47.1%-62.5%]; P = .43). Conclusions and Relevance: In this comparative effectiveness study of pediatric patients with AML treated in 2 consecutive clinical trials, Black patients had worse outcomes compared with White patients after treatment with standard induction therapy, but this disparity was eliminated by treatment with augmented induction therapy. When accounting for ACS10 scores, no outcome disparities were seen between Black and White patients. Our results suggest that using pharmacogenomics parameters to tailor induction regimens for both Black and White patients may narrow the racial disparity gap in patients with AML.

Detailed analysis of metastatic colorectal cancer patients who developed cardiotoxicity on another fluoropyrimidine and switched to S-1 treatment (subgroup analysis of the CardioSwitch-study).

BACKGROUND AND PURPOSE: The CardioSwitch-study demonstrated that patients with solid tumors who develop cardiotoxicity on capecitabine or 5-fluorouracil (5-FU) treatment can be safely switched to S-1, an alternative fluoropyrimidine (FP). In light of the European Medicines Agency approval of S-1 in metastatic colorectal cancer (mCRC), this analysis provides more detailed safety and efficacy information, and data regarding metastasectomy and/or local ablative therapy (LAT), on the mCRC patients from the original study. MATERIALS AND METHODS: This retrospective cohort study was conducted at 12 European centers. The primary endpoint was recurrence of cardiotoxicity after switch. For this analysis, safety data are reported for 78 mCRC patients from the CardioSwitch cohort (N = 200). Detailed efficacy and outcomes data were available for 66 mCRC patients. RESULTS: Data for the safety of S-1 in mCRC patients were similar to the original CardioSwitch cohort and that expected for FP-based treatment, with no new concerns. Recurrent cardiotoxicity (all grade 1) with S-1-based treatment occurred in 4/78 (5%) mCRC patients; all were able to complete FP treatment. Median progression-free survival from initiation of S-1-based treatment was 9.0 months and median overall survival 26.7 months. Metastasectomy and/or LAT was performed in 33/66 (50%) patients, and S-1 was successfully used in recommended neoadjuvant/conversion or adjuvant-like combination regimens and schedules as for standard FPs. INTERPRETATION: S-1 is a safe and effective FP alternative when mCRC patients are forced to discontinue 5-FU or capecitabine due to cardiotoxicity and can be safely used in the standard recommended regimens, settings, and schedules.

Hand-foot syndrome in cancer patients on capecitabine: examining prevalence, impacts, and associated risk factors at a cancer centre in Malaysia.

INTRODUCTION: Hand-foot syndrome (HFS) significantly impacts quality of life in cancer patients undergoing capecitabine treatment. This study assessed capecitabine-associated HFS prevalence, its impacts on chemotherapy treatment, and identified risk factors in multiracial Malaysian patients. METHODS: We included adult cancer patients receiving capecitabine at Sarawak General Hospital for at least two cycles from April 1, 2021 to June 30, 2022. HFS rates, time to HFS, and proportions of HFS-related treatment modifications were determined. Characteristics between patients with and without HFS were compared and multivariable logistic regression was used to identify risk factors for all-grade HFS and grade ≥2. RESULTS: Among 369 patients, 185 (50.1%) developed HFS, with 14.6% experiencing grade ≥2 and 21.6% (40/185) underwent treatment modifications. Risk factors for all-grade HFS include older age (OR 1.03 95%CI 1.01, 1.06), prior chemotherapy (OR 2.09 95%CI 1.22, 3.58), higher capecitabine dose (OR 2.96 95%CI 1.62, 5.38), prolonged treatment (OR 1.36 95%CI 1.21, 1.51), folic acid intake (OR 3.27 95%CI 1.45, 7.35) and lower neutrophil count (OR 0.77 95%CI 0.66, 0.89). For HFS grade ≥2, older age (OR 1.04 95%CI 1.01, 1.08), female sex (OR 2.10 95%CI 1.05, 4.18), Chinese race (OR 2.10 95%CI 1.06, 4.18), and higher capecitabine dose (OR 2.62 95%CI 1.28, 5.35) are significant risk factors. Use of calcium channel blockers were associated with reduced risks of all-grade HFS (OR 0.27, 95%CI 0.12, 0.60) and grade ≥2 (OR 0.21 95%CI 0.06, 0.78). CONCLUSION: This study provides real-world data on capecitabine-induced HFS in Malaysian patients and identifies risk factors that may offer insights into its understanding and management.

Gene Expression and DNA Methylation Profiling Suggest Potential Biomarkers for Azacitidine Resistance in Myelodysplastic Syndrome.

Myelodysplastic syndrome/neoplasm (MDS) comprises a group of heterogeneous hematopoietic disorders that present with genetic mutations and/or cytogenetic changes and, in the advanced stage, exhibit wide-ranging gene hypermethylation. Patients with higher-risk MDS are typically treated with repeated cycles of hypomethylating agents, such as azacitidine. However, some patients fail to respond to this therapy, and fewer than 50% show hematologic improvement. In this context, we focused on the potential use of epigenetic data in clinical management to aid in diagnostic and therapeutic decision-making. First, we used the F-36P MDS cell line to establish an azacitidine-resistant F-36P cell line. We performed expression profiling of azacitidine-resistant and parental F-36P cells and used biological and bioinformatics approaches to analyze candidate azacitidine-resistance-related genes and pathways. Eighty candidate genes were identified and found to encode proteins previously linked to cancer, chronic myeloid leukemia, and transcriptional misregulation in cancer. Interestingly, 24 of the candidate genes had promoter methylation patterns that were inversely correlated with azacitidine resistance, suggesting that DNA methylation status may contribute to azacitidine resistance. In particular, the DNA methylation status and/or mRNA expression levels of the four genes (AMER1, HSPA2, NCX1, and TNFRSF10C) may contribute to the clinical effects of azacitidine in MDS. Our study provides information on azacitidine resistance diagnostic genes in MDS patients, which can be of great help in monitoring the effectiveness of treatment in progressing azacitidine treatment for newly diagnosed MDS patients.

Analysis of chemoresistance characteristics and prognostic relevance of postoperative gemcitabine adjuvant chemotherapy in pancreatic cancer.

AIM: To investigate the relationship between chemoresistance in pancreatic cancer patients receiving postoperative gemcitabine adjuvant therapy and specific clinical/pathological characteristics, as well as its impact on patient prognosis. METHODS: From June 2018 to June 2021, clinical and pathological data of 148 pancreatic cancer patients were collected, and 101 patients were followed up for tumor recurrence/metastasis and survival status. The correlation between chemoresistance and specific clinical/pathological characteristics or patient prognosis was retrospectively analyzed. RESULTS: Of the 148 patients, 78 were in the chemoresistance group and 70 in the non-chemoresistance group. Univariate analysis showed that the development of chemoresistance may be related to patient age, combined diabetes, preoperative CA19-9 level, tumor size, AJCC stage, vascular invasion, and positive lymph node ratio. Furthermore, subsequent multivariate analysis incorporating these variables indicated that tumor size may be a key factor influencing chemoresistance (p < 0.001, OR = 1.584). Log-rank test showed patients in the chemoresistance group had worse overall survival (OS) (HR = 2.102, p = 0.018) and progression free survival (PFS) (HR = 3.208, p = 0.002) than patients in the non-chemoresistance group; and patients with smaller size tumors (diameter ≤3 cm) had significantly better OS (HR = 2.923, p < 0.001) and PFS (HR = 2.930, p = 0.003) than those with larger size tumors (diameter >3 cm). CONCLUSIONS: Patients with pancreatic cancer receiving postoperative gemcitabine adjuvant therapy are more likely to develop chemoresistance when their tumor sizes are larger (diameter >3 cm). Development of chemoresistance exacerbates the prognosis of patients with pancreatic cancer, and larger tumor size is also a risk factor for poor prognosis in these patients.

A pharmacodynamic assay to monitor treatment with the hypomethylating cytosine analogs, decitabine and azacitidine.

Hypomethylating therapies using decitabine or azacitidine are actively investigated to treat acute myeloid leukemia, myelodysplastic syndromes, as maintenance therapy after allogenic stem cell transplant and hemoglobinopathies. The therapeutic mechanism is to de-repress genes that have been turned off through oncogenesis or development via methylation. The therapy can be non-cytotoxic at low dosage, sparing healthy stem cells and operating on committed precursors. Because the methods of determining maximum tolerated dose are not well suited to this paradigm, and because the mechanism of action, which is depletion of DNA methylase 1 (DNMT1), is complex and dependent on passing through a cell cycle, a pharmacodynamic assay that measures DNMT1 can inform clinical trials aimed at establishing and improving therapy. Herein, we provide an assay that measures DNMT1 relative levels in circulating T cells of peripheral blood.

Correlation between relative dose intensity of adjuvant S-1 chemotherapy and psoas muscle mass volume and survival after resection of pancreatic ductal adenocarcinoma: A retrospective study.

This study aimed to investigate the prognostic relationship between relative dose intensity (RDI) of adjuvant S-1 chemotherapy and psoas muscle mass volume (PMV) in patients with resected pancreatic ductal adenocarcinoma. We enrolled 105 patients with histologically confirmed pancreatic ductal adenocarcinoma who had undergone pancreatectomy. Adjuvant S-1 chemotherapy was administered to 72 (68.6%) of the 105 patients and not to the remaining 33 patients. Patients who received adjuvant S-1 chemotherapy were stratified into high- and low-RDI groups by the cutoff value for RDI. Five-year overall survival (OS) and relapse-free survival (RFS) rates were significantly higher in the high- than in the low-RDI group. Similarly, both the 5-year OS and RFS rates were significantly greater among patients in the high-PMV group than among patients in the low-PMV group. The RDI was an independent prognostic factor in our study patients. Furthermore, patients who received adjuvant S-1 chemotherapy were stratified into 3 groups: those with both high RDI and high-PMV, Group A; those with either high RDI or high PMV (but not both), Group B; and those with both low RDI and low-PMV, group C. There were statistically significant differences in 5-year OS and RFS between 3 patient groups (5-year overall survival: P = .023, 5-year relapse-free survival: P = .001). The area under the curve for the combination of RDI and PMV (0.674) was greater than that for RDI alone (0.645). A sufficient dosage of adjuvant S-1 chemotherapy is important in improving survival of patients with resected pancreatic ductal adenocarcinoma. A combination of RDI and PMV may predict the prognosis of patients with resected pancreatic ductal adenocarcinoma more effective than RDI alone.

Contribution of aldehyde oxidase to methotrexate-induced hepatotoxicity: in vitro and pharmacoepidemiological approaches.

BACKGROUND: Methotrexate (MTX) is partially metabolized by aldehyde oxidase (AOX) in the liver and its clinical impact remains unclear. In this study, we aimed to demonstrate how AOX contributes to MTX-induced hepatotoxicity in vitro and clarify the relationship between concomitant AOX inhibitor use and MTX-associated liver injury development using the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS). METHODS: We assessed intracellular MTX accumulation and cytotoxicity using HepG2 cells. We used the FAERS database to detect reporting odds ratio (ROR)-based MTX-related hepatotoxicity event signals. RESULTS: AOX inhibition by AOX inhibitor raloxifene and siRNA increased the MTX accumulation in HepG2 cells and enhanced the MTX-induced cell viability reduction. In the FAERS analysis, the ROR for MTX-related hepatotoxicity increased with non-overlap of 95% confidence interval when co-administered with drugs with higher Imax, u (maximum unbound plasma concentration)/IC50 (half-maximal inhibitory concentration for inhibition of AOX) calculated based on reported pharmacokinetic data. CONCLUSION: AOX inhibition contributed to MTX accumulation in the liver, resulting in increased hepatotoxicity. Our study raises concerns regarding MTX-related hepatotoxicity when co-administered with drugs that possibly inhibit AOX activity at clinical concentrations.

Expression of gemcitabine metabolizing enzymes and stromal components reveal complexities of preclinical pancreatic cancer models for therapeutic testing.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) poorly responds to antineoplastic agents. Discrepancies between preclinical success and clinical failure of compounds has been a continuous challenge and major obstacle in PDAC research. AIM: To investigate the association of the tumor microenvironment (TME) composition and gemcitabine metabolizing enzyme (GME) expression in vitro and several in vivo models. METHODS: mRNA expression and protein levels of GME (cytosolic 5'-nucleotidase 1 A; NT5C1A, cytidine deaminase; CDA, deoxycytidine kinase; DCK), gemcitabine transporters (ENT1, ENT2, RRM1, RRM2) and stromal components (hyaluroninc acid, podoplanin, masson trichrome, picrosirius) were assessed by qRT-PCR and immunohistochemistry in murine LSL-KrasG12D/+;LSL-Trp53R172 H/+; Pdx-1-Cre (KPC), orthotopically transplanted mice (OTM), human primary resected PDAC tissue (hPRT), corresponding patient-derived xenograft (PDX) mice, and KPC-SPARC-/- mice. mRNA expression of GME was analyzed in PDAC cell lines (Panc-1, MIA PaCa, BXPC3 and L3.6) upon incubation on collagen or pancreatic stellate cell (PSC) conditioned media by qRT-PCR. RESULTS: Endogenous KPC tumors exhibited significantly higher levels of GME compared to OTM. However, GME levels did not differ between hPRT and corresponding PDX mice. Using Kendalls Tau correlation coefficient we did not show a significant correlation of GME and components of the TME except for NT5C1A and hyaluronic acid in PDX mice (p=0.029). GME were not significantly altered upon SPARC depletion in vivo, and upon treatment with PSC-conditioned media or incubation on collagen plated dishes in vitro. CONCLUSIONS: Our findings suggest that the expression of GME is independent from the deposition of stromal components. KPC mice are most appropriate to study stromal composition whereas PDX mice maintain GME expression of the corresponding hPRT and could be best suited for pharmacokinetic studies.

Prolactin receptor potentiates chemotherapy through miRNAs-induced G6PD/TKT inhibition in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies, with a notoriously dismal prognosis. As a competitive inhibitor of DNA synthesis, gemcitabine is the cornerstone drug for treating PDAC at all stages. The therapeutic effect of gemcitabine, however, is often hindered by drug resistance, and the underlying mechanisms remain largely unknown. It is unclear whether their response to chemotherapeutics is regulated by endocrine regulators, despite the association between PDAC risk and endocrine deregulation. Here, we show that prolactin receptor (PRLR) synergizes with gemcitabine in both in vitro and in vivo treatment of PDAC. Interestingly, PRLR promotes the expression of miR-4763-3p and miR-3663-5p, two novel miRNAs whose functions are unknown. Furthermore, the analysis of transcriptome sequencing data of tumors from lactating mouse models enriches the PPP pathway, a multifunctional metabolic pathway. In addition to providing energy, the PPP pathway mainly provides a variety of raw materials for anabolism. We demonstrate that two key enzymes of the pentose phosphate pathway (PPP), G6PD and TKT, are directly targeted by miR-4763-3p and miR-3663-5p. Notably, miR-4763-3p and miR-3663-5p diminish the nucleotide synthesis of the PPP pathway, thereby increasing gemcitabine sensitivity. As a result, PRLR harnesses these two miRNAs to suppress PPP and nucleotide synthesis, subsequently elevating the gemcitabine sensitivity of PDAC cells. Also, PDAC tissues and tumors from LSL-KrasG12D/+, LSL-Trp53R172H/+, and PDX1-cre (KPC) mice exhibit downregulation of PRLR. Bisulfite sequencing of PDAC tissues revealed that PRLR downregulation is due to epigenetic methylation. In this study, we show for the first time that the endocrine receptor PRLR improves the effects of gemcitabine by boosting two new miRNAs that block the PPP pathway and nucleotide synthesis by inhibiting two essential enzymes concurrently. The PRLR-miRNAs-PPP axis may serve as a possible therapeutic target to supplement chemotherapy advantages in PDAC.

Lethal Capecitabine Toxicity in Patients With Complete Dihydropyrimidine Dehydrogenase Deficiency Due to Ultra-Rare DPYD Variants.

A DPD deficiency should be considered in case of severe toxicity even in the absence of common risk variants in DPYD.

Enhancing therapeutic efficacy: sustained delivery of 5-fluorouracil (5-FU) via thiolated chitosan nanoparticles targeting CD44 in triple-negative breast cancer.

Our current study reports the successful synthesis of thiolated chitosan-based nanoparticles for targeted drug delivery of 5-Fluorouracil. This process was achieved through the ionic gelation technique, aiming to improve the efficacy of the chemotherapeutic moiety by modifying the surface of the nanoparticles (NPs) with a ligand. We coated these NPs with hyaluronic acid (HA) to actively target the CD44 receptor, which is frequently overexpressed in various solid malignancies, including breast cancer. XRD, FTIR, SEM, and TEM were used for the physicochemical analysis of the NPs. These 5-Fluorouracil (5-FU) loaded NPs were evaluated on MDA-MB-231 (a triple-negative breast cell line) and MCF-10A (normal epithelial breast cells) to determine their in vitro efficacy. The developed 5-FU-loaded NPs exhibited a particle size within a favorable range (< 300 nm). The positive zeta potential of these nanoparticles facilitated their uptake by negatively charged cancer cells. Moreover, they demonstrated robust stability and achieved high encapsulation efficiency. These nanoparticles exhibited significant cytotoxicity compared to the crude drug (p < 0.05) and displayed a promising release pattern consistent with the basic diffusion model. These traits improve the pharmacokinetic profile, efficacy, and ability to precisely target these nanoparticles, offering a potentially successful anticancer treatment for breast cancer. However, additional in vivo assessments of these formulations are obligatory to confirm these findings.

BET inhibition decreases HMGCS2 and sensitizes resistant pancreatic tumors to gemcitabine.

Efforts to develop targetable molecular bases for drug resistance for pancreatic ductal adenocarcinoma (PDAC) have been equivocally successful. Using RNA-seq and ingenuity pathway analysis we identified that the superpathway of cholesterol biosynthesis is upregulated in gemcitabine resistant (gemR) tumors using a unique PDAC PDX model with resistance to gemcitabine acquired in vivo. Analysis of additional in vitro and in vivo gemR PDAC models showed that HMG-CoA synthase 2 (HMGCS2), an enzyme involved in cholesterol biosynthesis and rate limiting in ketogenesis, is overexpressed in these models. Mechanistic data demonstrate the novel findings that HMGCS2 contributes to gemR and confers metastatic properties in PDAC models, and that HMGCS2 is BRD4 dependent. Further, BET inhibitor JQ1 decreases levels of HMGCS2, sensitizes PDAC cells to gemcitabine, and a combination of gemcitabine and JQ1 induced regressions of gemR tumors in vivo. Our data suggest that decreasing HMGCS2 may reverse gemR, and that HMGCS2 represents a useful therapeutic target for treating gemcitabine resistant PDAC.