PITX2 functions as a transcription factor for GPX4 and protects pancreatic cancer cells from ferroptosis.

Ferroptosis inhibits tumor progression in pancreatic cancer cells, while PITX2 is known to function as a pro-oncogenic factor in various tumor types, protecting them from ferroptosis and thereby promoting tumor progression. In this study, we sought to investigate the regulatory role of PITX2 in tumor cell ferroptosis within the context of pancreatic cancer. We conducted PITX2 knockdown experiments using lentiviral infection in two pancreatic cancer cell lines, namely PANC-1 and BxPC-3. We assessed protein expression through immunoblotting and mRNA expression through RT-PCR. To confirm PITX2 as a transcription factor for GPX4, we employed Chromatin Immunoprecipitation (ChIP) and Dual-luciferase assays. Furthermore, we used flow cytometry to measure reactive oxygen species (ROS), lipid peroxidation, and apoptosis and employed confocal microscopy to assess mitochondrial membrane potential. Additionally, electron microscopy was used to observe mitochondrial structural changes and evaluate PITX2's regulation of ferroptosis in pancreatic cancer cells. Our findings demonstrated that PITX2, functioning as a transcription factor for GPX4, promoted GPX4 expression, thereby exerting an inhibitory effect on ferroptosis in pancreatic cancer cells and consequently promoting tumor progression. Moreover, PITX2 enhanced the invasive and migratory capabilities of pancreatic cancer cells by activating the WNT signaling pathway. Knockdown of PITX2 increased ferroptosis and inhibited the proliferation of PANC-1 and BxPC-3 cells. Notably, the inhibitory effect on ferroptosis resulting from PITX2 overexpression in these cells could be countered using RSL3, an inhibitor of GPX4. Overall, our study established PITX2 as a transcriptional regulator of GPX4 that could promote tumor progression in pancreatic cancer by reducing ferroptosis. These findings suggest that PITX2 may serve as a potential therapeutic target for combating ferroptosis in pancreatic cancer.

Analysis of factors influencing pancreatic fistula after minimally invasive pancreaticoduodenectomy and establishment of a new prediction model for clinically relevant pancreatic fistula.

BACKGROUND: Postoperative pancreatic fistula (POPF) is the most prevalent complications following minimally invasive pancreaticoduodenectomy (MIPD). Only one model related to MIPD exists, and previous POPF scoring prediction methods are based on open pancreaticoduodenectomy patients. Our objectives are to determine the variables that may increase the probability of pancreatic fistula following MIPD and to develop and validate a POPF predictive risk model. METHODS: Data from 432 patients who underwent MIPD between July 2015 and May 2022 were retrospectively collected. A nomogram prediction model was created using multivariate logistic regression analysis to evaluate independent factors for POPF in patients undergoing MIPD in the modeling cohort. The area under the curve (AUC) of the receiver operating characteristic curve (ROC) and the calibration curve were used to verify the nomogram prediction model internally and externally within the modeling cohort and the verification cohort. RESULTS: Multivariate logistic regression analysis showed that body mass index (BMI), albumin, triglycerides, pancreatic duct diameter, pathological diagnosis and intraoperative bleeding were independent variables for POPF. On the basis of this information, a model for the prediction of risks associated with POPF was developed. In accordance with the ROC analysis, the modeling cohort's AUC was 0.819 (95% CI 0.747-0.891), the internal validation cohort's AUC was 0.830 (95% CI 0.747-0.912), and the external validation cohort's AUC was 0.793 (95% CI 0.671-0.915). Based on the calibration curve, the estimated values of POPF have a high degree of concordance with the actual values that were measured. CONCLUSIONS: This model for predicting the probability of pancreatic fistula following MIPD has strong predictive capacity and can provide a trustworthy predictive method for the early screening of high-risk patients with pancreatic fistula after MIPD and timely clinical intervention.

Clinical outcomes of minimally invasive duodenum-preserving pancreatic head resection.

BACKGROUND: The procedure of total duodenum-preserving pancreatic head resection (DPPHRt) has been reported frequently, but rare in minimally invasive procedure, especially robotic-assisted operation. Here we share our experience and analyze the clinical outcomes of minimally invasive DPPHRt in the treatment of benign lesions or low-grade malignant tumors of the pancreatic head in this study. MATERIALS AND METHODS: From October 2016 to January 2022, three patients received robot-assisted DPPHRt(RA-DPPHRt), and seventeen patients received laparoscopic DPPHRt(LDPPHRt). Data were retrospectively collected in terms of demographic characteristics (age, gender, body mass index, and pathological diagnosis), intraoperative variables (operative time, estimated blood loss), and post-operative variables (post-operative hospital stay, and complications). RESULTS: All 20 patients received minimally invasive total duodenum-preserving pancreatic head resection successfully without conversion, including 8 males and 12 females. Pathological diagnosis suggested 1 case of serous cystadenoma (SCA), 4 cases of intraductal papillary mucinous neoplasm (IPMN) ,5 cases of mucinous cystic neoplasm (MCN), 4 cases of pancreatic neuroendocrine neoplasm (PNET), 2 cases of chronic pancreatitis (CP),4 case of solid pseudopapillary tumor (SPT). The average operation time was (285.35 ± 95.13 min), ranging from 95 to 420 min. The average estimate blood loss was (196.50 ± 174.45ml) ,ranging from 10 to 600ml.The average post-operative hospital stay was(20.90 ± 14.44days),ranging from 8 to 54 days. Postoperative complications occurred in 10 patients (50%). A total of 5 patients (20%) suffered grade B or C pancreatic fistula. Two patients (10%) suffered from biliary fistula. Two patients (10%) suffered from delayed gastric emptying. One patient (5%) suffered from abdominal bleeding. The 90-day mortality was 0. No patient was observed tumor recurrence and new-onset diabetes but one developed diarrhea. CONCLUSION: RA-DPPHRt or LDPPHRt provided a minimally invasive approach with good organ-preservation for patients with benign and low-grade malignant pancreatic head tumor. It is only recommended to be performed in high-volume pancreatic centers by experienced pancreatic surgeons.

PITX2 in pancreatic stellate cells promotes EMT in pancreatic cancer cells via the Wnt/ß-catenin pathway.

Since the prognosis of patients with pancreatic cancer is very poor and there is a lack of treatment methods, this study is performed to investigate the function of PITX2 in pancreatic stellate cells (PSCs) in the progression of pancreatic cancer. Scientific hypotheses are proposed according to bioinformatics analysis and tissue microarray analysis. Stable knockdown of PITX2 in PSCs is achieved through lentiviral infection. The relative expressions of PITX2, α-SMA, vimentin, CTNNB1, AXIN1 and LEF1 are measured in wild-type PSCs and PITX2-knockdown PSCs. Proliferative capacity is measured by EdU assay. After coculture with PSCs, the proliferation, invasion and migration capacity of pancreatic cancer cells are tested. EMT and Wnt/ß-catenin downstream genes of pancreatic cancer cells are investigated to reveal the potential mechanism. Bioinformatics analysis reveals that the PITX2 gene is highly expressed in stromal cells in pancreatic cancer and is correlated with squamous-type PDAC. Analysis of PDAC tissue microarray further demonstrates that high PITX2 level in stromal cells is correlated with poor prognosis in PDAC. After stable knockdown of PITX2 in PSCs, the relative protein levels of α-SMA, vimentin, CTNNB1, AXIN1 and LEF1 are decreased, and the proliferative capacity of PSCs is also decreased. After coculture with PSCs, in which PITX2 expression is downregulated, the proliferation, invasion and migration capacities of pancreatic cancer cells are inhibited. Thus, our results show that PITX2-silenced PSCs inhibit the growth, migration and invasion of pancreatic cancer cells via reduced EMT and Wnt/ß-catenin signaling.

SETD8 inhibits ferroptosis in pancreatic cancer by inhibiting the expression of RRAD.

BACKGROUND: As an oncogene, SETD8 can promote tumour growth and tumour cell proliferation. This study aims to reveal the relationship between SETD8 and ferroptosis in pancreatic cancer and its role in pancreatic cancer to provide a possible new direction for the comprehensive treatment of pancreatic cancer. METHODS: The downstream targets were screened by RNA sequencing analysis. Western blot, Real-time Quantitative PCR (qPCR) and immunohistochemistry showed the relationship between genes. Cell proliferation analysis and cell metabolite analysis revealed the function of genes. Chromatin immunoprecipitation (CHIP) assays were used to study the molecular mechanism. RESULTS: The potential downstream target of SETD8, RRAD, was screened by RNA sequencing analysis. A negative correlation between SETD8 and RRAD was found by protein imprinting, Real-time Quantitative PCR (qPCR) and immunohistochemistry. Through cell proliferation analysis and cell metabolite analysis, it was found that RRAD can not only inhibit the proliferation of cancer cells but also improve the level of lipid peroxidation of cancer cells. At the same time, chromatin immunoprecipitation analysis (CHIP) was used to explore the molecular mechanism by which SETD8 regulates RRAD expression. SETD8 inhibited RRAD expression. CONCLUSIONS: SETD8 interacts with the promoter region of RRAD, which epigenetically silences the expression of RRAD to reduce the level of lipid peroxidation in pancreatic cancer cells, thereby inhibiting ferroptosis in pancreatic cancer cells and resulting in poor prognosis of pancreatic cancer.

Comparison of laparoscopic and open pancreaticoduodenectomy for the treatment of distal cholangiocarcinoma: A propensity score matching analysis.

Background: There are few studies comparing the oncological outcomes of laparoscopic pancreaticoduodenectomy (LPD) and open pancreaticoduodenectomy (OPD) for distal cholangiocarcinoma (DCC). Our objective was to assess the short-term efficacy and long-term survival of LPD and OPD in patients with DCC. Methods: The data of 124 DCC patients who underwent LPD or OPD at the Third Affiliated Hospital of Soochow University from May 2010 to May 2021 were retrospectively analyzed. Propensity score matching was performed to balance the two groups of baseline characteristics. After 1:1 matching, the overall survival (OS) of the two groups was compared by the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were used to identify independent predictors of OS. Results: The original cohort consisted of 124 patients. Nineteen patients were excluded because of incomplete baseline or follow-up data, and the remaining 105 patients were divided into two cohorts (45 in the LPD group and 60 in the OPD group). The LPD group showed more favorable results in OS analysis (LPD vs. OPD, 56.4 [46.2-66.5] vs. 48.9 [36.4-61.4], months, P=0. 01). PSM analysis identified 30 pairs of patients, and differences between matching groups were still significant (LPD vs. OPD, 67.9[58.2-77.6] vs. 47.4[31.4-67.5], months, P=0.002). Moreover, the LPD group experienced less intraoperative bleeding (LPD vs. OPD, 292.67 vs. 519.17 mL, P=0.002). Univariate analysis showed that surgical modality (P=0.012), carbohydrate antigen 19-9 (P=0.043), carcinoembryonic antigen (P=0.003), neutrophil-to-lymphocyte ratio (P=0.012), blood transfusion (P=0.031), clinically relevant postoperative pancreatic fistula (P<0.001) and lymphatic metastasis (P=0.004) were predictors of OS. Multivariate Cox analysis demonstrated that carbohydrate antigen 19-9 (P=0.048), carcinoembryonic antigen (P=0.031) and lymphatic metastasis (P=0.023) were independent predictive factors of OS. However, adjuvant therapy had no significant effect on the OS of DCC patients after radical pancreaticoduodenectomy (P>0.05). Conclusions: For DCC patients, LPD may be a more recommended procedure because of its advantages over OPD in terms of intraoperative bleeding and long-term survival.

A positive feedback loop of ARF6 activates ERK1/2 signaling pathway via DUSP6 silencing to promote pancreatic cancer progression.

ERK1/2 are essential proteins mediating mitogen-activated protein kinase signaling downstream of RAS in pancreatic adenocarcinoma (PDAC). Our previous study reveals that ARF6 plays a positive regulatory role in ERK1/2 pathway in a feedback loop manner. A significant part of the literature on ARF6 has emphasized its oncogenic effect as an essential downstream molecule of ERK1/2, and no research has been done on the regulation mechanisms of the feedback loop between ARF6 and the ERK1/2 signaling pathway. In the present study, we explore the gene network downstream of ARF6 and find that DUSP6 may be the critical signal molecule in the positive feedback loop between ARF6 and ERK1/2. Specifically, to elucidate the negative correlations between ARF6 and DUSP6 in pancreatic cancer, we examine their expressions in pancreatic cancer tissues by immunohistochemical staining. Then the impact of DUSP6 on the proliferation and apoptosis of PDAC cells are investigated by gain-of-function and loss-of-function approaches. Mechanism explorations uncover that ARF6 suppresses the expression of DUSP6, which is responsible for the dephosphorylation of ERK1/2. Altogether, these results indicate that DUSP6 plays a tumor-suppressive role and acts as an intermediate molecule between ARF6 and ERK1/2 in PDAC cells, thereby forming a positive feedback loop.

Influence of Body Mass Index on Perioperative Outcomes Following Pancreaticoduodenectomy.

Background: Overweight and obesity are increasing year by year all over the world, and there is a correlation between overweight and obesity and the risk of pancreatic cancer. However, the relationship between overweight and obesity and perioperative outcomes of pancreaticoduodenectomy (PD) was controversial. The purpose of this study was to investigate the effect of body mass index (BMI) on the perioperative outcome of PD. Methods: This study retrospectively evaluated 227 patients who underwent PD from 2015 to 2019. The patients were divided into three groups: underweight group (BMI <18.5 kg/m2), normal weight group (18.5 ≤ BMI <25 kg kg/m2), and overweight group (BMII ≥25 kg/m2). The association between different BMI groups and different perioperative results was discussed. Finally, the independent risk factors of clinically relevant-postoperative pancreatic fistula (CR-POPF) were analyzed by multivariate logistic regression. Results: The level of preoperative albumin was higher in patients of overweight group (P = .03). The incidence of hypertension increased gradually in the three BMI groups (P = . 039). The preoperative median CA19-9 level was significantly higher in the underweight group than that in the control groups (P = .001). The median operation time in the high BMI group was significantly longer than that in the other two groups. High BMI was an independent risk factor influencing CR-POPF after PD (P = .022, odds ratio 2.253, 95% confidence interval 1.123-4.518). Conclusions: Operation time of PD was increased in patients with high BMI. High BMI was an independent risk factor for the incidence of CR-POPF after PD. However, PD surgery is safe and feasible for patients with different BMI, and overweight and obese patients should not refuse PD surgery because of their BMI.

Laparoscopic vs. open pancreaticoduodenectomy: a comparative study in elderly people.

The purpose of the study is to evaluate whether laparoscopic pancreatoduodenectomy (LPD) is safe and feasible for elderly patients. From December 2015 to January 2019, 142 LPD surgeries and 93 OPD surgeries were performed by the same surgeon in the third affiliated hospital of Soochow University. After applying the inclusion and exclusion criteria, we retrospectively collected the date of three defined groups: LPD aged < 70 years (group I, 84 patients), LPD aged ≥ 70 years (group II, 56 patients) and OPD aged ≥ 70 years (group III, 28 patients). Baseline characteristics and short-term surgical outcomes of group I and group II, group II and group III were compared. Totally, 168 patients were included in this study; 100 cases were men; 68 cases were women; mean age was 67.9 ± 9.5 years. LPD does not perform as well in elderly as it does in non-elderly patients in terms of intraoperative blood loss (300.0 (200.0-500.0) ml vs. 200.0 (100.0-300.0) ml, p = 0.003), proportion of intraoperative transfusion (17.9% vs. 6.0%, p = 0.026) and time to oral intake (5.0 (4.0-7.0) day vs. 5.0 (3.0-6.0) day, p = 0.036). Operative time, conversion rate, postoperative stay, and proportion of reoperation, Clavien-Dindo classification, 30-day readmission and 90-day mortality were similar in two groups. In elderly patients, when compared with OPD, LPD had the advantage of shorter time to start oral intake (5.0 (4.0-7.0) day vs. 7.0 (5.0-11.3) day, p = 0.005) but the disadvantage of longer operative time (380.0 (306.3-447.5) min vs. 292.5 (255.0-342.5) min, p < 0.001) and higher hospitalization cost (12447.3 (10,189.7-15,340.0) euros vs. 7251.9 (8994.0-11,717.4) euros, p < 0.001). There was no difference between the two groups in terms of postoperative stay, and proportion of reoperation, Clavien-Dindo classification, 30-day readmission and 90-day mortality. LPD is safe and feasible for elderly people, but we need to consider its high cost and long operative time over OPD.

Meta-analysis of the prognostic value of C-C chemokine receptor type 7 in patients with solid tumors.

BACKGROUND: Expression of C-C chemokine receptor type 7 (CCR7) is associated with the prognosis of several cancers. The aim of this study was to conduct the meta-analysis to determine the prognostic value of CCR7 expression in solid tumors. MATERIALS AND METHODS: We searched for relevant literature in the PubMed, Embase, and Cochrane Library databases (last updated on January 15, 2018). The associations of CCR7 expression with overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS), progress-free survival (PFS), and disease-specific survival (DSS) were estimated. RESULTS: In total, 30 qualified studies including 3,413 patients were enrolled. The results revealed that higher expression of CCR7 predicted poorer OS (pooled HR =1.79; 95% CI =1.49-2.16; P<0.001) and PFS (pooled HR =2.18; 95% CI =1.49-3.18; P<0.001), but was not associated with DFS (pooled HR =1.69; 95% CI =0.79-3.61; P=0.175), RFS (pooled HR =1.29; 95% CI =0.48-3.44; P=0.618), or DSS (pooled HR =3.06; 95% CI =0.38-24.83; P<0.294). CONCLUSION: From this meta-analysis, we concluded that high expression of CCR7 in tumor tissue is associated with poor survival in patients with solid tumors, and may be a prognostic biomarker for tumor progression.