Identification of gemcitabine resistance-related AHNAK2 gene associated with prognosis and immune infiltration in pancreatic cancer.

Purpose: Gemcitabine is a basic chemotherapy drug for pancreatic cancer (PC), but resistance is common and causes tumor recurrence and metastasis. Therefore, it is significant to explore gemcitabine resistance-related molecules for individualized treatment and prognosis assessment of PC. Methods: In this study, transcriptome sequencing and TCGA database analysis were performed, and a differentiated gene AHNAK2 was screened. MEXPRESS database, tissue microarray analysis, and CIBERSORT and TIMER databases were used to correlate AHNAK2 expression with clinicopathological features and prognosis and immune infiltration of PC. Enrichment analysis was used to investigate the significant biological processes associated with AHNAK2. Results: AHNAK2 was highly expressed in gemcitabine-resistant cells. High expression of AHNAK2 increased the risk of poor overall survival (OS) and progression-free survival (PFS) in PC. Clinicopathologic analysis revealed that AHNAK2 correlated with KRAS, TP53 mutations, histologic type, short OS, N stage, and elevated CA199 levels in PC. Knockdown of AHNAK2 inhibited the ability of cell proliferation and colony formation and enhanced the toxic effect of gemcitabine in PC. Meanwhile, the knockdown of AHNAK2 expression enhanced cell-ECM adhesion, inhibited cell-cell adhesion, and downregulated the KRAS/p53 signaling pathway in PC. Furthermore, AHNAK2 was correlated with immune infiltration, especially B cells and macrophages. Conclusions: Our study unveils for the first time the pivotal role of AHNAK2 in PC, particularly its association with gemcitabine resistance, clinical prognosis, and immune infiltration. AHNAK2 not only drives the proliferation and drug resistance of PC cells by potentially activating the KRAS/p53 pathway but also significantly impacts cell-cell and cell- ECM adhesion. Additionally, AHNAK2 plays a crucial role in modulating the tumor immune microenvironment. These insights underscore AHNAK2's unique potential as a novel therapeutic target for overcoming gemcitabine resistance, offering new perspectives for PC treatment strategies.

Prognostic value of RRM1 and its effect on chemoresistance in pancreatic cancer.

PURPOSE: Pancreatic cancer (PC) remains a lethal disease, and gemcitabine resistance is prevalent. However, the biomarkers suggestive of gemcitabine resistance remain unclear. METHODS: Bioinformatic tools identified ribonucleotide reductase catalytic subunit M1 (RRM1) in gemcitabine-related datasets. A cox regression model revealed the predictive value of RRM1 with clinical features. An external clinical cohort confirmed the prognostic value of RRM1. RRM1 expression was validated in gemcitabine-resistant cells in vitro and in orthotopic PC model. CCK8, flow cytometry, transwell migration, and invasion assays were used to explore the effect of RRM1 on gemcitabine-resistant cells. The CIBERSORT algorithm investigated the impact of RRM1 on immune infiltration. RESULTS: The constructed nomogram based on RRM1 effectively predicted prognosis and was further validated. Moreover, patients with higher RRM1 had shorter overall survival. RRM1 expression was significantly higher in PC tissue and gemcitabine-resistant cells in vitro and in vivo. RRM1 knockdown reversed gemcitabine resistance, inhibited migration and invasion. The infiltration levels of CD4 + T cells, CD8 + T cells, neutrophils, and plasma cells correlated markedly with RRM1 expression, and communication between tumor and immune cells probably depends on NF-κB/mTOR signaling. CONCLUSION: RRM1 may be a potential marker for prognosis and a target marker for gemcitabine resistance in PC.

Arsenic trioxide sensitizes pancreatic cancer cells to gemcitabine through downregulation of the TIMP1/PI3K/AKT/mTOR axis.

Gemcitabine (GEM) is the first-line medication for pancreatic ductal adenocarcinoma (PDAC). However, over some treatment cycles, GEM sensitivity declines and chemotherapeutic resistance develops, resulting in tumor recurrence and metastasis. Therefore, it is critical to elucidate the mechanism of GEM chemoresistance. And a specific drug that is closely related to the mechanism is urgently required to sensitize GEM. Here, tissue inhibitor of matrix metalloproteinases 1 (TIMP1) and phosphorylated mammalian target of rapamycin (p-mTOR) were found to be substantially elevated in PDAC patients and were associated with worse overall survival. The TIMP1/PI3K/AKT/mTOR pathway was found in GEM-resistant PDAC cells and was revealed to be involved in epithelial-mesenchymal transition (EMT) and apoptosis. Furthermore, arsenic trioxide (ATO), a basic therapeutic drug for acute promyelocytic leukemia, mediated TIMP1 reduction by inducing reactive oxygen species generation and hampered the subsequent PI3K/AKT/mTOR axis. Moreover, the combination of ATO and GEM cooperatively suppressed the TIMP1/PI3K/AKT/mTOR pathway, synergistically inhibited EMT and promoted apoptosis. In vitro and in vivo, ATO combined with GEM has a collaborative anticancer effect, inhibiting cancer cell proliferation, migration, invasion, and suppressing tumor growth both in PDAC parental and GEM-resistant cells. Overall, the TIMP1/PI3K/AKT/mTOR pathway is present in PDAC and linked to GEM resistance. ATO suppresses the axis to sensitize GEM and reverse GEM resistance, suggesting a promising treatment for the disease.

TIMP1 derived from pancreatic cancer cells stimulates Schwann cells and promotes the occurrence of perineural invasion.

Perineural invasion (PNI) occurs in most pancreatic ductal adenocarcinomas (PDACs). The relationship between cancer cells and peripheral nerves, however, is unknown. Therefore, we focused on the cooperation of PDAC cells and peripheral nerve astrocytes, Schwann cells (SCs), in PNI. The mutual tumor-supportive secretory cytokines between SCs (sNF96.2) and PDAC cells (PANC-1, BxPC-3) were screened by human cytokine arrays and verified. The prognostic value of selected cytokines and SC-associated markers was confirmed in PDAC patients. TIMP1 and CCL7 were found to form a paracrine feedback loop between PDAC cells and SCs. PDAC cell-derived TIMP1 promotes SCs proliferation and migration via CD63/PI3K/AKT signaling. CCL7 secreted from SCs enhances PDAC cell migration, invasion and expression of TIMP1 via CCR2/STAT3. PDAC cell-SC cooperation in PNI was blocked when TIMP1 knockdown in vitro and in vivo. Finally, TIMP1, CCL7 and SC-associated markers were correlated with PNI and prognosis in PDAC patients. In conclusion, SCs collaborate with PDAC cells through the TIMP1-CCL7 paracrine feedback loop to promote PNI. TIMP1 knockdown in PDAC cells suppresses PNI. Strategies to disrupt the TIMP1-CCL7 feedback loop might be developed to inhibit PNI in PDAC.

LINC00152 down-regulated miR-193a-3p to enhance MCL1 expression and promote gastric cancer cells proliferation.

The present work aimed to probe into the effect of long non-coding RNA (lncRNA) LINC00152 on gastric cancer (GC) cells proliferation by regulating miR-193a-3p and its target gene MCL1 Transfected si-LINC00152 was used to down-regulate LINC00152, and cells proliferation was measured by the cell counting kit-8 (CCK-8) assay. Cell apoptosis and cell cycle were analyzed by flow cytometry (FCM). Besides, we also detected the potential functional effects of differential expression of LINC00152 in vivo using nude mouse xenograft model. We overexpressed and downexpressed miR-193a-3p to study the in vitro effect of miR-193a-3p on GC cells proliferation and vitality. And MCL1 was silenced by shRNA to investigate the effect of MCL1 on proliferation of GC cells. In this research, LINC00152 was proven to have a higher expression level in GC tissues than in the adjacent normal tissues. GC cells proliferation was inhibited after LINC00152 was down-regulated. LINC00152 inhibited the expression of miR-193a-3p, which negatively regulated MCL1 In addition, GC cells proliferation was inhibited by cell transfection with shRNA-MCL1, and enhanced by transfection with miR-193a-3p mimics. Our study suggested that LINC00152 was overexpressed in GC tissues, and it down-regulated miR-193a-3p to enhance MCL1 expression thereby promoting GC cells proliferation.

Inverse association between Bmi-1 and RKIP affecting clinical outcome of gastric cancer and revealing the potential molecular mechanisms underlying tumor metastasis and chemotherapy resistance.

BACKGROUND: B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) and Raf kinase inhibitory protein (RKIP) are involved in cancer metastasis and chemotherapeutic resistance, respectively. In this study, we evaluated the association between Bmi-1 and RKIP and outcome of gastric cancer through clinical data analysis and in vitro experiments. METHODS: Bmi-1 expression and RKIP expression were observed in 107 cases of gastric cancer through use of tissue microarray technology to identify their correlations with clinicopathological parameters, patient survival, and susceptibility to chemotherapy. The correlation was confirmed in gastric cancer cell lines, analyzed further by gene overexpression and silencing analysis, a cell invasion assay, and a chemosensitivity test. RESULTS: Positive expression of Bmi-1 was highly correlated with T classification and clinical stage. Diminished or lost expression of RKIP was significantly associated with T classification, lymph node metastasis, distant metastasis, and clinical stage. Bmi-1 is negatively and RKIP is positively related to patient survival. Positive expression of Bmi-1 and negative expression of RKIP are associated with poor patient survival and modest efficacy of postoperative chemotherapy. A meaningfully inverse association between Bmi-1 and RKIP was found in tissue microarray studies, and was verified further in gastric cancer cell lines. Moreover, gene overexpression and silencing analysis indicated that RKIP might be regulated by Bmi-1. Furthermore, the impacts of Bmi-1 on cell invasion and chemotherapy resistance were rescued by knockdown of RKIP. CONCLUSIONS: Our study implies that detection of Bmi-1 and RKIP is valuable in predicting patient survival and therapeutic response in gastric cancer, and the inverse association between Bmi-1 and RKIP reveals the potential molecular mechanisms underlying tumor metastasis and chemotherapy resistance.

Effect of Preoperative Biliary Drainage on Complications Following Pancreatoduodenectomy: A Meta-Analysis.

Preoperative biliary drainage (PBD) prior to pancreatoduodenectomy (PD) is still controversial; therefore, the aim of this study was to examine the impact of PBD on complications following PD. A meta-analysis was carried out for all relevant randomized controlled trials (RCTs), prospective and retrospective studies published from inception to March 2015 that compared PBD and non-PBD (immediate surgery) for the development of postoperative complications in PD patients. Pooled odds ratio (OR) and 95% confidence interval (CI) were estimated using fixed-effect analyses, or random-effects analyses if there was statistically significant heterogeneity (P < 0.05). Eight RCTs, 13 prospective studies, 20 retrospective studies, and 3 Chinese local retrospective studies with 6286 patients were included in this study. In a pooled analysis, there were no significant differences between PBD and non-PBD group in the risks of mortality, morbidity, intra-abdominal abscess, sepsis, hemorrhage, pancreatic leakage, and biliary leakage. However, subgroup analysis of RCTs yielded a trend toward reduced risk of morbidity in PBD group (OR 0.48, CI 0.24 to 0.97; P = 0.04). Compared with non-PBD, PBD was associated with significant increase in the risk of infectious complication (OR 1.52, CI 1.07 to 2.17; P = 0.02), wound infection (OR 2.09, CI 1.39 to 3.13; P = 0.0004), and delayed gastric emptying (DGE) (OR 1.37, CI 1.08 to 1.73; P = 0.009). This meta-analysis suggests that biliary drainage before PD increased postoperative infectious complication, wound infection, and DGE. In light of the results of the study, PBD probably should not be routinely carried out in PD patients.

[Reconstruction methods of digestive tract after pancreaticodudenectomy: a systematic review and meta-analysis of RCTs].

OBJECTIVE: To investigate different types of anastomosis and reconstruction techniques after pancreaticodudenectomy with meat-analysis. METHODS: Systematically literature search was performed through Wanfang, PubMed, EMBASE, Web of Science and Cochrane Library database without restriction to regions, publication types, or languages. A total of 17 randomized controlled trials met the criteria and were evaluated by Jadad scale. Fixed and random-effects models were used to measure the pooled estimates, including pancreatic fistula, bile leakage, hemorrhage, delay gastric emptying(DGE), mortality, reoperation. RESULTS: Meta analysis revealed that patients undergoing pancreaticogastrostomy had a lower incidence of pancreatic fistula and bile leakage(OR=0.60, 95%CI:0.44-0.82, P=0.001; OR=0.33, 95%CI:0.13-0.82, P=0.02) as compared to pancreaticojejunostomy. In pancreaticoenterostomy group, pancreatic duct-mucosa pancreaticoenterostomy had no significant differences with traditional end-to-end anastomosis in terms of overall postoperative morbidity, and development of postoperative pancreatic fistula, reoperation, perioperative death. External stent placement drainage group had a lower postoperative overall complication rate and incidence of pancreatic fistula, especially the II(-III( grade pancreatic fistula, and a shorter hospital stay than non-stent drainage group(all P<0.05). CONCLUSIONS: Pancreaticogastrostomy should be recommended as digestive tract reconstruction after pancreaticodudenectomy and assistant external stent drainage is also necessary.

Screening of the nutritional risk of patients with gastric carcinoma before operation by NRS 2002 and its relationship with postoperative results.

AIM: To evaluate the nutritional risk of patients with gastric carcinoma using the methodologies of European Nutritional Risk Screening 2002 (NRS 2002) and its relationship with postoperative results. METHODS: We prospectively evaluated the nutritional risk of 314 cases of gastric carcinoma patients in one center from 2004 to 2007 with NRS 2002, in accordance with China's normal body mass index (BMI), and observed its relationship with postoperative complications, mortality and length of hospital stay. RESULTS: Of 337 cases, 314 (93.1%) were suitable for assessment by NRS 2002.The number of patients with a score > or = 3 was 125 before operation, comprising 39.8% of patients with gastric carcinoma. The rate of complications (26.2%) of the preoperative nutritional risk group (NRS 2002 score > or = 3) was higher than those in the preoperative nutritional normal group (NRS 2002 score < 3) (P < 0.05). Assessed by multivariate logistics regression analysis, the odds ratio of developing complications was 2.366 (P < 0.05) and 2.277 (P < 0.05) by NRS 2002 score and clinicopathological stage, respectively. The correlation between length of hospital stay and nutritional risk was also assessed by Pearson correlation analysis. The Pearson coefficient was 0.177 (P = 0.002). CONCLUSION: Preoperative nutrition score (NRS 2002) > or = 3 predicted more postoperative complications and longer length of hospital stay. It indicated that preoperative nutritional support was necessary in patients with a preoperative nutritional score (NRS 2002) > or = 3.