Small non-coding RNAs and pancreatic ductal adenocarcinoma: Linking diagnosis, pathogenesis, drug resistance, and therapeutic potential.

This review comprehensively investigates the intricate interplay between small non-coding RNAs (sncRNAs) and pancreatic ductal adenocarcinoma (PDAC), a devastating malignancy with limited therapeutic options. Our analysis reveals the pivotal roles of sncRNAs in various facets of PDAC biology, spanning diagnosis, pathogenesis, drug resistance, and therapeutic strategies. sncRNAs have emerged as promising biomarkers for PDAC, demonstrating distinct expression profiles in diseased tissues. sncRNA differential expression patterns, often detectable in bodily fluids, hold potential for early and minimally invasive diagnostic approaches. Furthermore, sncRNAs exhibit intricate involvement in PDAC pathogenesis, regulating critical cellular processes such as proliferation, apoptosis, and metastasis. Additionally, mechanistic insights into sncRNA-mediated pathogenic pathways illuminate novel therapeutic targets and interventions. A significant focus of this review is dedicated to unraveling sncRNA mechanisms underlying drug resistance in PDAC. Understanding these mechanisms at the molecular level is imperative for devising strategies to overcome drug resistance. Exploring the therapeutic landscape, we discuss the potential of sncRNAs as therapeutic agents themselves as their ability to modulate gene expression with high specificity renders them attractive candidates for targeted therapy. In summary, this review integrates current knowledge on sncRNAs in PDAC, offering a holistic perspective on their diagnostic, pathogenic, and therapeutic relevance. By elucidating the roles of sncRNAs in PDAC biology, this review provides valuable insights for the development of novel diagnostic tools and targeted therapeutic approaches, crucial for improving the prognosis of PDAC patients.

Elucidation of the Gemcitabine Transporters of Escherichia coli K-12 and Gamma-Proteobacteria Linked to Gemcitabine-Related Chemoresistance.

Gemcitabine (2',2'-difluoro-2'-deoxycytidine), a widely used anticancer drug, is considered a gold standard in treating aggressive pancreatic cancers. Gamma-proteobacteria that colonize the pancreatic tumors contribute to chemoresistance against gemcitabine by metabolizing the drug to a less active and deaminated form. The gemcitabine transporters of these bacteria are unknown to date. Furthermore, there is no complete knowledge of the gemcitabine transporters in Escherichia coli or any other related proteobacteria. In this study, we investigate the complement of gemcitabine transporters in E. coli K-12 and two common chemoresistance-related bacteria (Klebsiella pneumoniae and Citrobacter freundii). We found that E. coli K-12 has two high-affinity gemcitabine transporters with distinct specificity properties, namely, NupC and NupG, whereas the gemcitabine transporters of C. freundii and K. pneumoniae include the NupC and NupG orthologs, functionally indistinguishable from their counterparts, and, in K. pneumoniae, one additional NupC variant, designated KpNupC2. All these bacterial transporters have a higher affinity for gemcitabine than their human counterparts. The highest affinity (KM 2.5-3.0 µΜ) is exhibited by NupGs of the bacteria-specific nucleoside-H+ symporter (NHS) family followed by NupCs (KM 10-13 µΜ) of the concentrative nucleoside transporter (CNT) family, 15-100 times higher than the affinities reported for the human gemcitabine transporter hENT1/SLC29A1, which is primarily associated with gemcitabine uptake in the pancreatic adenocarcinoma cells. Our results offer a basis for further insight into the role of specific bacteria in drug availability within tumors and for understanding the structure-function differences of bacterial and human drug transporters.

Growth Hormone Receptor Antagonist Markedly Improves Gemcitabine Response in a Mouse Xenograft Model of Human Pancreatic Cancer.

Chemotherapy treatment against pancreatic ductal adenocarcinoma (PDAC) is thwarted by tumoral activation of multiple therapy resistance pathways. The growth hormone (GH)-GH receptor (GHR) pair is a covert driver of multimodal therapy resistance in cancer and is overexpressed in PDAC tumors, yet the therapeutic potential of targeting the same has not been explored. Here, we report that GHR expression is a negative prognostic factor in patients with PDAC. Combinations of gemcitabine with different GHR antagonists (GHRAs) markedly improve therapeutic outcomes in nude mice xenografts. Employing cultured cells, mouse xenografts, and analyses of the human PDAC transcriptome, we identified that attenuation of the multidrug transporter and epithelial-to-mesenchymal transition programs in the tumors underlie the observed augmentation of chemotherapy efficacy by GHRAs. Moreover, in human PDAC patients, GHR expression strongly correlates with a gene signature of tumor promotion and immune evasion, which corroborate with that in syngeneic tumors in wild-type vs. GH transgenic mice. Overall, we found that GH action in PDAC promoted a therapy-refractory gene signature in vivo, which can be effectively attenuated by GHR antagonism. Our results collectively present a proof of concept toward considering GHR antagonists to improve chemotherapeutic outcomes in the highly chemoresistant PDAC.

Interleukin-1 receptor 1 deficiency worsens hepatocellular carcinoma, while gemcitabine treatment alleviates the hepatocellular carcinoma-induced increase in intra-hepatic immune cells.

BACKGROUND AND AIM: Primary liver cancer, particularly hepatocellular carcinoma (HCC), represents a substantial global health challenge. Although immune checkpoint inhibitors are effective in HCC treatment, several patients still experience disease progression. Interleukin-1 (IL-1) regulates immunity and inflammation. We investigate the role of IL-1 in HCC development and progression and determine the potential therapeutic impact of gemcitabine in treating HCC. METHODS: Hydrodynamics-based transfection, employing the sleeping beauty transposase system, delivered surrogate tumor antigens, NRAS (NRAS proto-oncogene, GTPase), ShP53, and SB100 to C57BL/6 mice. A basic HCC mouse model was established. Pathogen-free animals were tested for serum and hepatotoxicity. The HCC prognosis was monitored using alanine aminotransferase and aspartate aminotransferase levels. Liver histology immunohistochemistry and mouse splenocyte/intra-hepatic immune cell flow cytometry were conducted. IL-1ß levels in human and mouse serum were assessed. RESULTS: Interleukin-1ß levels were elevated in patients with HCC compared with those in non-HCC controls. Hepatic IL-1ß levels were higher in HCC mouse models than those in non-HCC mice, suggesting localized hepatic inflammation. IL-1 receptor type 1 (IL-1R1) knockout (IL-1R1-/-) mice exhibited less severe HCC progression than that in wild-type mice, despite the high intra-hepatic IL-1ß concentration. IL-1R1-/- mice exhibited increased hepatic levels of myeloid-derived suppressor cells and regulatory T cells, which may exacerbate HCC. Gemcitabine significantly reduced the HCC tumor burden, improved liver conditions, and increased survival rates in HCC mouse models. Gemcitabine reduced the hepatic levels of myeloid-derived suppressor cells and regulatory T cells, potentially alleviating immune suppression in the liver. CONCLUSIONS: Targeting IL-1 or combining gemcitabine with immunotherapy is a promising approach for treating advanced-stage HCC.

Nab-paclitaxel plus S-1 versus nab-paclitaxel plus gemcitabine in patients with advanced pancreatic cancer: a multicenter, randomized, phase II study.

BACKGROUND: Encouraging antitumor activity of nab-paclitaxel plus S-1 (AS) has been shown in several small-scale studies. This study compared the efficacy and safety of AS versus standard-of-care nab-paclitaxel plus gemcitabine (AG) as a first-line treatment for advanced pancreatic cancer (PC). METHODS: In this multicenter, randomized, phase II trial, eligible patients with unresectable, locally advanced, or metastatic PC were recruited and randomly assigned (1:1) to receive AS (nab-paclitaxel 125 mg/m2 on days 1 and 8; S-1 twice daily on days 1 through 14) or AG (nab-paclitaxel 125 mg/m2 on days 1 and 8; gemcitabine 1000 mg/m2 on days 1 and 8) for 6 cycles. The primary endpoint was progression-free survival (PFS). RESULTS: Between July 16, 2019, and September 9, 2022, 62 patients (AS, n = 32; AG, n = 30) were treated and evaluated. With a median follow-up of 8.36 months at preplanned interim analysis (data cutoff, March 24, 2023), the median PFS (8.48 vs 4.47 months; hazard ratio [HR], 0.402; P = .002) and overall survival (OS; 13.73 vs 9.59 months; HR, 0.226; P < .001) in the AS group were significantly longer compared to the AG group. More patients had objective response in the AS group than AG group (37.50% vs 6.67%; P = .005). The most common grade 3-4 adverse events were neutropenia and leucopenia in both groups, and gamma glutamyl transferase increase was observed only in the AG group. CONCLUSION: The first-line AS regimen significantly extended both PFS and OS of Chinese patients with advanced PC when compared with the AG regimen, with a comparable safety profile. (ClinicalTrials.gov Identifier: NCT03636308).

Characterization of Equilibrative Nucleoside Transport of the Pancreatic Cancer Cell Line: Panc-1.

Objectives: Gemcitabine, a first-line chemotherapeutic nucleoside analog drug (NAD) for pancreatic cancer, faces limitations due to drug resistance. Characterizing pancreatic cancer cells' transport characteristics may help identify the mechanisms behind drug resistance, and develop more effective therapeutic strategies. Therefore, in this study, we aimed to determine the nucleoside transport properties of Panc-1 cells, one of the commonly used pancreatic adenocarcinoma cell lines. Materials and Methods: To assess the presence of equilibrative nucleoside transporter-1 (ENT-1) in Panc-1 cells, we performed immunofluorescence staining, western blot analysis, and S-(4-nitrobenzyl)-6-thioinosine (NBTI) binding assays. We also conducted standard uptake assays to measure the sodium-independent uptake of [3H]-labeled chloroadenosine, hypoxanthine, and uridine. In addition, we determined the half-maximal inhibitory concentration (IC50) of gemcitabine. Statistical analyses were performed using GraphPad Prism version 8.0 for Windows. Results: The sodium-independent uptake of [3H]-labeled chloroadenosine, hypoxanthine, and uridine was measured using standard uptake assays, and the transport rates were determined as 111.1 ± 3.4 pmol/mg protein/10 s, 62.5 ± 4.8 pmol/mg protein/10 s, and 101.3 ± 2.5 pmol/mg protein/10 s, respectively. Furthermore, the presence of ENT-1 protein was confirmed using NBTI binding assays (Bmax 1.52 ± 0.1 pmol/mg protein; equilibrium dissociation constant 0.42 ± 0.1 nM). Immunofluorescence assays and western blot analysis also revealed ENT-1 in Panc-1 cells. The determined IC50 of gemcitabine in Panc-1 cells was 2 µM, indicating moderate sensitivity. Conclusion: These results suggest that Panc-1 is a suitable preclinical cellular model for studying NAD transport properties and potential therapies in pancreatic cancer and pharmaceutical research.

Cytostatic Bacterial Metabolites Interfere with 5-Fluorouracil, Doxorubicin and Paclitaxel Efficiency in 4T1 Breast Cancer Cells.

The microbiome is capable of modulating the bioavailability of chemotherapy drugs, mainly due to metabolizing these agents. Multiple cytostatic bacterial metabolites were recently identified that have cytostatic effects on cancer cells. In this study, we addressed the question of whether a set of cytostatic bacterial metabolites (cadaverine, indolepropionic acid and indoxylsulfate) can interfere with the cytostatic effects of the chemotherapy agents used in the management of breast cancer (doxorubicin, gemcitabine, irinotecan, methotrexate, rucaparib, 5-fluorouracil and paclitaxel). The chemotherapy drugs were applied in a wide concentration range to which a bacterial metabolite was added in a concentration within its serum reference range, and the effects on cell proliferation were assessed. There was no interference between gemcitabine, irinotecan, methotrexate or rucaparib and the bacterial metabolites. Nevertheless, cadaverine and indolepropionic acid modulated the Hill coefficient of the inhibitory curve of doxorubicin and 5-fluorouracil. Changes to the Hill coefficient implicate alterations to the kinetics of the binding of the chemotherapy agents to their targets. These effects have an unpredictable significance from the clinical or pharmacological perspective. Importantly, indolepropionic acid decreased the IC50 value of paclitaxel, which is a potentially advantageous combination.

Encapsulation of Gemcitabine on Porphyrin Aluminum Metal-Organic Framework by Mechano-Chemistry, Delayed Drug Release and Cytotoxicity to Pancreatic Cancer PANC-1 Cells.

Gemcitabine is a widely used antimetabolite drug of pyrimidine structure, which can exist as a free-base molecular form (Gem). The encapsulated forms of medicinal drugs are of interest for delayed and local drug release. We utilized, for the first time, a novel approach of mechano-chemistry by liquid-assisted grinding (LAG) to encapsulate Gem on a "matrix" of porphyrin aluminum metal-organic framework Al-MOF-TCPPH2 (compound 2). The chemical bonding of Gem to compound 2 was studied by ATR-FTIR spectroscopy and powder XRD. The interaction involves the C=O group of Gem molecules, which indicates the formation of the encapsulation complex in the obtained composite. Further, the delayed release of Gem from the composite was studied to phosphate buffered saline (PBS) at 37 °C using an automated drug dissolution apparatus equipped with an autosampler. The concentration of the released drug was determined by HPLC-UV analysis. The composite shows delayed release of Gem due to the bonded form and constant concentration thereafter, while pure Gem shows quick dissolution in less than 45 min. Delayed release of Gem drug from the composite follows the kinetic pseudo-first-order rate law. Further, for the first time, the mechanism of delayed release of Gem was assessed by the variable stirring speed of drug release media, and kinetic rate constant k was found to decrease when stirring speed is decreased (diffusion control). Finally, the prolonged time scale of toxicity of Gem to pancreatic cancer PANC-1 cells was studied by continuous measurements of proliferation (growth) for 6 days, using the xCELLigence real-time cell analyzer (RTCA), for the composite vs. pure drug, and their differences indicate delayed drug release. Aluminum metal-organic frameworks are new and promising materials for the encapsulation of gemcitabine and related small-molecule antimetabolites for controlled delayed drug release and potential use in drug-eluting implants.

Secretory Trefoil Factor 1 (TFF1) promotes gemcitabine resistance through chemokine receptor CXCR4 in Pancreatic Ductal Adenocarcinoma.

Gemcitabine is the first-line treatment option for patients with locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). However, the frequent adoption of resistance to gemcitabine by cancer cells poses a significant challenge in treating this aggressive disease. In this study, we focused on analyzing the role of trefoil factor 1 (TFF1) in gemcitabine resistance in PDAC. Analysis of PDAC TCGA and cell line datasets indicated an enrichment of TFF1 in the gemcitabine-resistant classical subtype and suggested an inverse correlation between TFF1 expression and sensitivity to gemcitabine treatment. The genetic ablation of TFF1 in PDAC cells enhanced their sensitivity to gemcitabine treatment in both in vitro and in vivo tumor xenografts. The biochemical studies revealed that TFF1 contributes to gemcitabine resistance through enhanced stemness, increasing migration ability of cancer cells, and induction of anti-apoptotic genes. We further pursued studies to predict possible receptors exerting TFF1-mediated gemcitabine resistance. Protein-protein docking investigations with BioLuminate software revealed that TFF1 binds to the chemokine receptor CXCR4, which was supported by real-time binding analysis of TFF1 and CXCR4 using SPR studies. The exogenous addition of TFF1 increased the proliferation and migration of PDAC cells through the pAkt/pERK axis, which was abrogated by treatment with a CXCR4-specific antagonist AMD3100. Overall, the present study demonstrates the contribution of the TFF1-CXCR4 axis in imparting gemcitabine resistance properties to PDAC cells.

Successful pre-surgical treatment with carboplatin and gemcitabine chemotherapy for a patient with muscle-invasive bladder cancer and severe renal dysfunction.

Radical cystectomy is the standard treatment for muscle-invasive bladder cancer, and pre-surgical treatment can improve survival. Carboplatin and gemcitabine chemotherapy is considered an effective, safe treatment for patients ineligible for cisplatin-based chemotherapy owing to reduced renal function. However, there is limited evidence on pre-surgical treatment with carboplatin and gemcitabine chemotherapy with glomerular filtration rates < 30 mL/min. We discuss the treatment of a patient who did not undergo surgery owing to bladder tumor size of 12 cm (cT3bN0M1a) and severe renal dysfunction (serum creatinine: 2.57 mg/dL, estimated glomerular filtration rate: 20.2 mL/min/1.73 m2). After the patient received two courses of carboplatin and gemcitabine chemotherapy, the bladder tumor size had reduced by 60%. No nausea or renal dysfunction was observed; febrile neutropenia improved with antibiotic therapy and granulocyte colony-stimulating factor. Then, he could undergo robot-assisted radical cystectomy after the pre-surgical chemotherapy treatment. Pre-surgical treatment with carboplatin and gemcitabine chemotherapy is a viable treatment option for patients with muscle-invasive bladder cancer and severe renal dysfunction.

Head-to-head comparison of treatment sequences in advanced pancreatic cancer-Real-world data from the prospective German TPK clinical cohort study.

There are no clear guidelines regarding the optimal treatment sequence for advanced pancreatic cancer, as head-to-head phase III randomised trials are missing. We assess real-world effectiveness of three common sequential treatment strategies by emulating a hypothetical randomised trial. This analysis included 1551 patients with advanced pancreatic cancer from the prospective, clinical cohort study Tumour Registry Pancreatic Cancer receiving FOLFIRINOX (n = 613) or gemcitabine/nab-paclitaxel (GEMNAB; n = 938) as palliative first-line treatment. We used marginal structural modelling to compare overall survival (OS) and time to deterioration (TTD) of health-related quality of life (HRQoL) between three common first- to second-line treatment sequences, adjusting for time-varying potential confounding. The sequences were: FOLFIRINOX→GEMNAB, GEMNAB→FOLFOX/OFF and GEMNAB→nanoliposomal irinotecan (NALIRI) + 5-fluorouracil. Outcome was also calculated stratified by patients' prognostic risk according to the Pancreatic Cancer Score. Median OS and TTD of HRQoL independent of risk were 10.7 [8.9, 11.9] and 6.4 [4.8, 7.7] months for FOLFIRINOX→GEMNAB, 8.4 [7.4, 9.7] and 5.8 [4.6, 7.1] months for GEMNAB→FOLFOX/OFF and 8.9 [7.8, 10.4] and 4.6 [4.1, 6.1] months for GEMNAB→NALIRI+5-fluorouracil. Compared to FOLFIRINOX→GEMNAB, OS and TTD were worse for poor-risk patients with GEMNAB→FOLFOX/OFF (OS: HR 2.09 [1.47, 2.98]; TTD: HR 1.97 [1.19, 3.27]) and those with GEMNAB→NALIRI+5-fluorouracil (OS: HR 1.35, [0.76, 2.39]; TTD: HR 2.62 [1.56, 4.42]). Brackets denote 95%-confidence intervals. The estimated real-world effectiveness of the three treatment sequences evaluated were largely comparable. Poor-risk patients might benefit from intensified treatment with FOLFIRINOX→GEMNAB in terms of clinical and patient-reported outcomes. Future randomised trials on sequential treatments in advanced pancreatic cancer are warranted.

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.

Cysteinylprolyl ester-mediated drug release from a lipid-drug conjugate.

For small-molecule drugs, lipidation via a cleavable linkage can extend half-life in circulation through interaction with albumin. Here we modified the cysteinylprolyl ester (CPE) system used in peptide thioester synthesis, which normally requires basic conditions, for use as an self-immolative linker and release device for a lipid-gemcitabine conjugate. To improve release under physiological conditions for medical application, a methyl group at the α-position of cysteine on the CPE unit was incorporated in anticipation of the Thorpe-Ingold effect. As a result, Ac-Gly-(α-Me)Cys(SH)-Pro-gemcitabine 11 drastically promoted the release of gemcitabine in comparison with Ac-Gly-Cys(SH)-Pro-gemcitabine 10. Furthermore, in the presence of bovine serum albumin and/or 2-mercaptoethanesulfonic acid, the gentle and continuous release of gemcitabine from the lipid-gemcitabine conjugate 16 was achieved. In addition to gemcitabine, this method could allow high clearance drugs, including nucleic acid and prostacyclin derivatives, to maintain their biological activity long enough to become effective.

Dual depletion of myeloid-derived suppressor cells and tumor cells with self-assembled gemcitabine-celecoxib nano-twin drug for cancer chemoimmunotherapy.

Myeloid-derived suppressor cells (MDSCs) have played a significant role in facilitating tumor immune escape and inducing an immunosuppressive tumor microenvironment. Eliminating MDSCs and tumor cells remains a major challenge in cancer immunotherapy. A novel approach has been developed using gemcitabine-celecoxib twin drug-based nano-assembled carrier-free nanoparticles (GEM-CXB NPs) for dual depletion of MDSCs and tumor cells in breast cancer chemoimmunotherapy. The GEM-CXB NPs exhibit prolonged blood circulation, leading to the preferential accumulation and co-release of GEM and CXB in tumors. This promotes synergistic chemotherapeutic activity by the proliferation inhibition and apoptosis induction against 4T1 tumor cells. In addition, it enhances tumor immunogenicity by immunogenic cell death induction and MDSC-induced immunosuppression alleviation through the depletion of MDSCs. These mechanisms synergistically activate the antitumor immune function of cytotoxic T cells and natural killer cells, inhibit the proliferation of regulatory T cells, and promote the M2 to M1 phenotype repolarization of tumor-associated macrophages, considerably enhancing the overall antitumor and anti-metastasis efficacy in BALB/c mice bearing 4T1 tumors. The simplified engineering of GEM-CXB NPs, with their dual depletion strategy targeting immunosuppressive cells and tumor cells, represents an advanced concept in cancer chemoimmunotherapy.

Urinary Bladder Carcinosarcoma (Sarcomatoid Carcinoma) With Long Survival After Transurethral Resection: A Case Report.

Carcinosarcoma or sarcomatoid carcinoma of the urinary bladder is a rare but aggressive bladder cancer characterized by malignant epithelial and mesenchymal components, with only a few cases reported in the literature so far. In this report, we discuss a case of a 74-year-old female nonsmoker who presented with intermittent hematuria and passage of clots in the last four months. Radiographic images showed an irregular mass lesion (6.2 x 6 cm) in the left lateral wall of the urinary bladder near to left vesicoureteral junction. The mass was completely removed with transurethral resection of the bladder tumor (TUR-BT). Histopathological study revealed high-grade carcinosarcoma, and immunohistochemistry showed diffuse positivity for vimentin, pan-cytokeratin (CK) and CK7, epithelial membrane antigen (EMA), and CK5/6. The patient declined radical cystectomy and only agreed to receive intravesical chemotherapy (gemcitabine), and she remains alive after more than four years of follow-up. Carcinosarcoma of the urinary bladder is a rare tumor primarily affecting older people, and it is most commonly treated with radical cystectomy and different combination treatments such as chemotherapy and radiation. However, tumor resection followed by intravesical chemotherapy may be an alternative option in the early stages of bladder carcinosarcoma for some patients, thereby avoiding the need for aggressive treatments, especially for elderly patients who decline to undergo radical surgery.

Human Equilibrative Nucleoside Transporter 1: Novel Biomarker and Prognostic Indicator for Patients with Gemcitabine-Treated Pancreatic Cancer.

Aim: This article aimed to find appropriate pancreatic cancer (PC) patients to treat with Gemcitabine with better survival outcomes by detecting hENT1 levels. Methods: We collected surgical pathological tissues from PC patients who received radical surgery in our hospital from September 2004 to December 2014. A total of 375 PC tissues and paired adjacent nontumor tissues were employed for the construction of 4 tissue microarrays (TMAs). The quality of the 4 TMAs was examined by HE staining. We performed immunohistochemistry analysis to evaluate hENT1 expression in the TMAs. Moreover, we detected hENT1 expression level and proved the role of hENT1 in cell proliferation, drug resistance, migration and invasion in vivo and vitro. Results: The results indicated that low hENT1 expression indicated a significantly poor outcome in PC patients, including shortened DFS (21.6±2.8 months versus 36.9±4.0 months, p<0.001) and OS (33.6±3.9 versus 39.6±3.9, p=0.004). Meanwhile, patients in stage I/II of TNM stage had a longer OS (40.2±3.4 versus 15.4±1.7, p=0.002) and DFS (31.0±3.1 versus 12.4±1.9, p=0.016) than patients in stage III/IV. Patients in M0 stage had a longer OS (39.7±3.4 versus 16.2±1.9, p=0.026) and DFS(30.7±3.0 versus 11.8±2.2, p=0.031) than patients in M1 stage, and patients with tumors not invading the capsule had a better DFS than those with tumor invasion into the capsule (30.8±3.0 versus 12.6±2.3, p=0.053). Patients with preoperative CA19-9 values ≤467 U/mL have longer DFS than that of patients who had preoperative CA19-9 values >467 U/mL (37.9±4.1 versus 22.9±4.0, p=0.04). In the subgroup analysis, a high hENT1 expression level was related to a longer OS(39.4±4.0 versus 31.5±3.9, p=0.001) and DFS(35.7±4.0 versus 20.6±2.7; p<0.0001) in the Gemcitabine subgroup. Conclusion: PC patients with high hENT1 expression have a better survival outcomes when receiving Gemcitabine. hENT1 expression can be a great prognostic indicator for PC patients to receive Gemcitabine treatment.

miRNA signatures underlie chemoresistance in the gemcitabine-resistant pancreatic ductal adenocarcinoma cell line MIA PaCa-2 GR.

Introduction: Chemotherapy resistance remains a significant challenge in the treatment of pancreatic adenocarcinoma (PDAC), particularly in relation to gemcitabine (Gem), a commonly used chemotherapeutic agent. MicroRNAs (miRNAs) are known to influence cancer progression and chemoresistance. This study investigates the association between miRNA expression profiles and gemcitabine resistance in PDAC. Methods: The miRNA expression profiles of a gemcitabine-sensitive (GS) PDAC cell line, MIA PaCa-2, and its gemcitabine-resistant (GR) progeny, MIA PaCa-2 GR, were analyzed. miRNA sequencing (miRNA-seq) was employed to identify miRNAs expressed in these cell lines. Differential expression analysis was performed, and Ingenuity Pathway Analysis (IPA) was utilized to elucidate the biological functions of the differentially expressed miRNAs. Results: A total of 1867 miRNAs were detected across both cell lines. Among these, 97 (5.2%) miRNAs showed significant differential expression between the GR and GS cell lines, with 65 (3.5%) miRNAs upregulated and 32 (1.7%) miRNAs downregulated in the GR line. The most notably altered miRNAs were implicated in key biological processes such as cell proliferation, migration, invasion, chemosensitization, alternative splicing, apoptosis, and angiogenesis. A subset of these miRNAs was further analyzed in patient samples to identify potential markers for recurrent tumors. Discussion: The differential miRNA expression profiles identified in this study highlight the complex regulatory roles of miRNAs in gemcitabine resistance in PDAC. These findings suggest potential targets for improving prognosis and tailoring treatment strategies in PDAC patients, particularly those showing resistance to gemcitabine. Future research should focus on validating these miRNAs as biomarkers for resistance and exploring their therapeutic potential in overcoming chemoresistance.

A fluorescent gemcitabine prodrug that follows a nucleoside transporter-independent internalization and bears enhanced therapeutic efficacy with respect to gemcitabine.

The multiplexity of cancer has rendered it the second leading cause of mortality worldwide and theragnostic prodrugs have gained popularity in recent years as a means of treatment. Theragnostic prodrugs enable the simultaneous diagnosis and therapy of tumors via high-precision real-time drug release monitoring. Herein, we report the development of the small theragnostic prodrug GF, based on the nucleoside anticancer agent gemcitabine and the fluorescent dye 5(6)-carboxyfluorescein. We have successfully demonstrated its efficient internalization in tumor cells, showing localization throughout both the early and late endocytic pathways. Its mechanism of cell internalization was evaluated, confirming its independence from nucleoside transporters. Its cellular localization via confocal microscopy revealed a clathrin-mediated endocytosis mechanism, distinguishing it from analogous compounds studied previously. Furthermore, GF exhibited stability across various pH values and in human blood plasma. Subsequently, its in vitro cytotoxicity was assessed in three human cancer cell lines (A549, U87 and T98). Additionally, its pharmacokinetic profile in mice was investigated and the consequent drug release was monitored. Finally, its in vivo visualization was accomplished in zebrafish xenotransplantation models and its in vivo efficacy was evaluated in A549 xenografts. The results unveiled an intriguing efficacy profile, positioning GF as a compelling candidate warranting further investigation.

Pancreatic cancer with liver metastasis maintaining complete response with gemcitabine monotherapy: A case report.

Pancreatic ductal adenocarcinoma (PDAC) is associated with a poor prognosis, and it has a recurrence rate of >70%, even in resectable cases. The treatment strategy for recurrent PDAC involves systemic chemotherapy, with gemcitabine (GEM) monotherapy historically serving as the standard of care. The present study describes the case of a patient with PDAC and postoperative liver metastases that maintained clinical complete remission (cCR) for >7 years following GEM monotherapy. A 63-year-old woman with upper abdominal pain was diagnosed with resectable PDAC and underwent pancreaticoduodenectomy. The patient was treated with GEM + S-1 as adjuvant chemotherapy for 6 months. Multiple liver metastases were detected 15 months post-operation and the patient was administered GEM alone. After 12 cycles, computed tomography showed cCR and GEM monotherapy was discontinued after 15 cycles. The patient has had no signs or symptoms of recurrence >7 years after the first recurrence. In addition, the present study analyzed PDAC resection specimens from four patients, including this case, to determine the expression levels of hENT1 protein in the tumor tissues. hENT1 is a transmembrane protein that acts as a nucleoside transporter and is a major mediator of GEM uptake into human cells. In the present case, hENT1 staining exhibited low frequency and weak positivity in the central region, whereas a strong positive reaction was observed in nearly all cell membranes at the invasive front of the cancer. The location, intensity, and frequency of hENT1 staining varied among cases. In conclusion, the efficacy of GEM may be predicted prior to treatment by evaluating hENT1 expression.

Phase II Trial of Romidepsin as Consolidation Therapy after Gemcitabine, Dexamethasone, and Cisplatin in Elderly Transplant-Ineligible Patients with Relapsed/Refractory Peripheral T-Cell Lymphoma.

Romidepsin is an important therapeutic option for patients with peripheral T-cell lymphoma (PTCL). However, the timing of romidepsin administration remains controversial. The objective of this study was to characterize the safety and efficacy of romidepsin as consolidation therapy after gemcitabine, dexamethasone, and cisplatin (GDP) therapy (GDPR). This study of patients treated between March 2019 and March 2021 was registered with the Japan Registry of Clinical Trials (registration number: jRCT0000000519). If complete response, partial response, or stable disease was confirmed after 2-4 GDP cycles, romidepsin was administered every 4 weeks for 1 year. Seven patients with relapsed/refractory (R/R) PTCL (T-follicular helper phenotype [n = 1] and angioimmunoblastic T-cell lymphoma [n = 6]) were included in this prospective study (PTCL-GDPR). After a median follow-up of 34 months of patients in PTCL-GDPR, the 2-year overall survival rate was 71%, and the overall response rate after treatment was 57%. Common adverse events in patients with PTCL-GDPR included hematological toxicities such as neutropenia, which improved with supportive treatment. There were no treatment-related mortalities. GDPR might be safe and effective in elderly transplant-ineligible patients with R/R PTCL; however, further investigation is required.