Evaluating the efficacy of laparoscopic radical antegrade modular pancreatosplenectomy in selected early-stage left-sided pancreatic cancer: a propensity score matching study.

BACKGROUND: Laparoscopic radical pancreatectomy is safe and beneficial for recectable pancreatic cancer, but the extent of resection for early-stage tumors remains controversial. METHODS: Consecutive patients with left-sided pancreatic cancer who underwent either laparoscopic radical antegrade modular pancreatosplenectomy (LRAMPS, n = 54) or laparoscopic distal pancreatosplecnectomy (LDP, n = 131) between October 2020 and December 2022 were reviewed. The preoperative radiological selection criteria were as follows: (1) tumor diameter ≤ 4 cm; (2) located ≥ 1 cm from the celiac trunk; (3) didn't invade the fascial layer behind the pancreas. RESULTS: After 1:1 propensity score matching (LRAMPS, n = 54; LDP, n = 54), baseline data were well-balanced with no differences. LRAMPS resulted in longer operation time (240.5 vs. 219.0 min, P = 0.020) and higher intraoperative bleeding volume (200 vs. 150 mL, P = 0.001) compared to LDP. Although LRAMPS harvested more lymph nodes (16 vs. 13, P = 0.008), there were no statistically significant differences in lymph node positivity rate (35.2% vs. 33.3%), R0 pancreatic transection margin (94.4% vs. 96.3%), and retroperitoneal margin (83.3% vs. 87.0%) rate. Postoperative complications did not significantly differ between the two groups. However, LRAMPS was associated with increased drainage volume (85.0 vs. 40.0 mL, P = 0.001), longer time to recover semi-liquid diet compared to LDP (5 vs. 4 days, P < 0.001) and increased daily bowel movement frequency. Tumor recurrence pattern and recurrence-free survival were comparable between the two groups, but the adjuvant chemotherapy regimens varied, and the completion rate of the 6-month intravenous chemotherapy was lower in the LRAMPS group compared to the LDP group (51.9% vs. 75.9%, P = 0.016). CONCLUSIONS: LRAMPS did not provide oncological benefits over LDP for left-sided pancreatic cancer within the selection criteria, but it increased operation time, intraoperative bleeding, and postoperative bowel movement frequency. These factors impacted the regimen selection and completion of adjuvant chemotherapy, consequently compromising the potential benefits of LRAMPS in achieving better local control.

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.

Cancer immunometabolism: advent, challenges, and perspective.

For decades, great strides have been made in the field of immunometabolism. A plethora of evidence ranging from basic mechanisms to clinical transformation has gradually embarked on immunometabolism to the center stage of innate and adaptive immunomodulation. Given this, we focus on changes in immunometabolism, a converging series of biochemical events that alters immune cell function, propose the immune roles played by diversified metabolic derivatives and enzymes, emphasize the key metabolism-related checkpoints in distinct immune cell types, and discuss the ongoing and upcoming realities of clinical treatment. It is expected that future research will reduce the current limitations of immunotherapy and provide a positive hand in immune responses to exert a broader therapeutic role.

The stromal microenvironment endows pancreatic neuroendocrine tumors with spatially specific invasive and metastatic phenotypes.

Cancer-associated fibroblasts (CAFs) play an important role in a variety of cancers. However, the role of tumor stroma in nonfunctional pancreatic neuroendocrine tumors (NF-PanNETs) is often neglected. Profiling the heterogeneity of CAFs can reveal the causes of malignant phenotypes in NF-PanNETs. Here, we found that patients with high stromal proportion had poor prognosis, especially for that with infiltrating stroma (stroma and tumor cells that presented an infiltrative growth pattern and no regular boundary). In addition, myofibroblastic CAFs (myCAFs), characterized by FAP+ and α-SMAhigh, were spatially closer to tumor cells and promoted the EMT and tumor growth. Intriguingly, only tumor cells which were spatially closer to myCAFs underwent EMT. We further elucidated that myCAFs stimulate TGF-ß expression in nearby tumor cells. Then, TGF-ß promoted the EMT in adjacent tumor cells and promoted the expression of myCAFs marker genes in tumor cells, resulting in distant metastasis. Our results indicate that myCAFs cause spatial heterogeneity of EMT, which accounts for liver metastasis of NF-PanNETs. The findings of this study might provide possible targets for the prevention of liver metastasis.

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.

Feasibility of laparoscopic versus open pancreatoduodenectomy following neoadjuvant chemotherapy for borderline resectable pancreatic cancer: a retrospective cohort study.

BACKGROUND: There is no evidence supporting the feasibility of laparoscopic pancreaticoduodenectomy (LPD) compared to open pancreatoduodenectomy (OPD) following neoadjuvant chemotherapy (NACT) for pancreatic ductal adenocarcinoma (PDAC). METHODS: The clinical data of consecutive patients with borderline resectable PDAC who received NACT and underwent either LPD or OPD between January 2020 and December 2022 at Fudan University Shanghai Cancer Center was prospectively collected and retrospectively analyzed. RESULTS: The analysis included 57 patients in the OPD group and 20 in the LPD group. Following NACT, the LPD group exhibited a higher median CA19-9 decrease rate compared to the OPD group (85.3% vs. 66.9%, P = 0.042). Furthermore, 3 anatomically borderline PDACs in the LPD group and 5 in the OPD group were downstaged into resectable status (30.0% vs. 12.3%, P = 0.069). According to RECIST criteria, 51 (66.2%) patients in the entire cohort were evaluated as having stable disease. The median operation time for the LPD group was longer than the OPD group (419 vs. 325 min, P < 0.001), while the venous resection rate was 35.0% vs. 43.9%, respectively (P = 0.489). There was no difference in the number of retrieved lymph nodes, with a median number of 18.5 in the LPD group and 22 in the OPD group, and the R1 margin rate (15.0% vs. 12.3%) was also comparable. The incidence of Clavien-Dindo complications (35.0% vs. 66.7%, P = 0.018) was lower in the LPD group compared to the OPD group. Multivariable regression analysis revealed that a tumor diameter > 3 cm before NACT (HR 2.185) and poor tumor differentiation (HR 1.805) were independent risk factors for recurrence-free survival, and a decrease rate of CA19-9 > 70% (OR 0.309) was a protective factor for early tumor recurrence and overall survival. CONCLUSIONS: LPD for PDAC following NACT is feasible and oncologically equivalent to OPD. Effective control of CA19-9 levels is beneficial in reducing early tumor recurrence and improving overall survival.

SMAD4 endows TGF-ß1-induced highly invasive tumor cells with ferroptosis vulnerability in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy prone to recurrence and metastasis. Studies show that tumor cells with increased invasive and metastatic potential are more likely to undergo ferroptosis. SMAD4 is a critical molecule in the transforming growth factor ß (TGF-ß) pathway, which affects the TGF-ß-induced epithelial-mesenchymal transition (EMT) status. SMAD4 loss is observed in more than half of patients with PDAC. In this study, we investigated whether SMAD4-positive PDAC cells were prone to ferroptosis because of their high invasiveness. We showed that SMAD4 status almost determined the orientation of transforming growth factor ß1 (TGF-ß1)-induced EMT via the SMAD4-dependent canonical pathway in PDAC, which altered ferroptosis vulnerability. We identified glutathione peroxidase 4 (GPX4), which inhibited ferroptosis, as a SMAD4 down-regulated gene by RNA sequencing. We found that SMAD4 bound to the promoter of GPX4 and decreased GPX4 transcription in PDAC. Furthermore, TGF-ß1-induced high invasiveness enhanced sensitivity of SMAD4-positive organoids and pancreas xenograft models to the ferroptosis inducer RAS-selective lethal 3 (RSL3). Moreover, SMAD4 enhanced the cytotoxic effect of gemcitabine combined with RSL3 in highly invasive PDAC cells. This study provides new ideas for the treatment of PDAC, especially SMAD4-positive PDAC.

Reconsidering the role of prophylactic pancreaticojejunostomy in pancreatic enucleation: balancing the benefits and risks.

BACKGROUND: The incidence of postoperative pancreatic fistula (POPF) following enucleation is high, and prophylactic pancreaticojejunostomy (PPJ) is frequently performed. Minimally invasive enucleation (MEN) has been demonstrated to be safe and feasible, leaving most enucleation wounds exposed. METHODS: The clinical data of 40 patients who underwent open enucleation with PPJ at our center between 2012 and 2021 were compared with those of 80 patients who underwent MEN. RESULTS: The MEN group had better outcomes than the PPJ group in terms of intraoperative bleeding (50.0 versus 100.0 mL), postoperative semi-liquid diet recovery (2.0 versus 5.0 days), and postoperative length of stay (7.7 versus 12.5 days). While the MEN group had higher rates of complex enucleation (60.0% versus 40.0%), main pancreatic duct repair (32.5% versus 10.0%), discharge with drains (48.8% versus 25.0%), and grade B POPFs (47.5% versus 17.5%). Both surgical methods effectively preserved pancreatic function; however, two patients in the PPJ group experienced severe haemorrhaging and died. Additionally, during the follow-up period, gastrointestinal bleeding was found and discomfort in the surgical area was reported. CONCLUSION: Pancreatic enucleation combined with PPJ should be avoided, and although a biochemical or grade B POPF may develop after MEN, it can be compensated for by preserving pancreatic function and ensuring a good long-term quality of life in the patients.

NMI promotes tumor progression and gemcitabine resistance in pancreatic cancer via STAT3-IFIT3 axis.

N-myc and STAT interactor (NMI) has been reported to interact with several transcription factors, including STATs family, c-Myc, N-Myc, and BRCA1, to indirectly affect transcription events and participate in multiple cellular processes. However, its function in pancreatic ductal adenocarcinoma (PDAC) has seldom been studied. In this study, we investigated the regulation of NMI on PDAC progression and uncovered the underlying molecular mechanisms. We found that NMI expression was significantly upregulated in PDAC and high NMI expression was related to a worse patient survival. Cell proliferation and migration assay, including cell viability, transwell assay, wound healing, and subcutaneous mouse model were utilized to confirm the function of NMI in PDAC progression. Downregulation of NMI abrogates tumor progression of PDAC both in vitro and in vivo. RNA sequencing was utilized to identify the downstream molecules of NMI and interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) was confirmed to be regulated by NMI in both mRNA and protein level. The binding function of NMI to STAT3 was essential in regulating the IFIT3 expression. Moreover, the NMI/STAT3-IFIT3 axis was identified to markedly facilitate the gemcitabine resistance in PDAC cells.

Minimally invasive enucleation of pancreatic tumors: The main pancreatic duct is no longer a restricted area.

Background: Tumors involving the main pancreatic duct (MPD) used to be a contraindication for enucleation. Methods: Clinical data of consecutive patients with pancreatic tumors who received laparoscopic or robotic enucleation (LEN or REN) between January 2019 and December 2021 at Fudan University Shanghai Cancer Center were analyzed. Results: Ninety-six patients were included in the analysis, with 55 in the LEN group and 41 in the REN group, and no conversion to laparotomy. Most tumors were located in the head of pancreas (71.9 %). The tumor diameter (3.1 vs. 1.9 cm) was larger, and more cystic tumors (92.7 % vs. 56.4 %) and more tumors involving the MPD (34.1 % vs. 3.6 %) were observed in the REN group. MPD support tube insertion was performed in 15 cases, with 11 in the REN group and 4 in the LEN group. The incidence of biochemical and grade B postoperative pancreatic fistula (POPF) was both 46.9 %, and no grade C POPF occurred. Among the 45 patients with grade B POPF, 28 cases (62.2 %) were due to carrying drainage tube >3 weeks without additional treatment, and only 4 cases required invasive treatment. For patients with MPD support tube implantation (n = 15), support tube fall-offs were observed in 12 cases, 2 patients had MPD dilatation, and no MPD stricture, stone formation or pancreatic atrophy was observed during follow-up. Conclusions: The incidence of POPF was high but still controllable without serious complications after minimally invasive enucleation. The MPD is no longer a restricted area, and the robotic system has advantages in handling complex enucleations.

Short-Term Outcomes Following Laparoscopic vs Open Pancreaticoduodenectomy in Patients With Pancreatic Ductal Adenocarcinoma: A Randomized Clinical Trial.

Importance: The safety and efficacy of laparoscopic pancreaticoduodenectomy for pancreatic ductal adenocarcinoma remain controversial. Objective: To compare laparoscopic and open pancreaticoduodenectomy performed by experienced surgeons in patients with pancreatic ductal adenocarcinoma. Design, Setting, and Participants: This was a noninferiority, open-label randomized clinical trial between September 20, 2019 and March 20, 2022, at 10 hospitals in China. A total of 412 adult patients were assessed for eligibility; 200 patients with histologically confirmed or clinically diagnosed pancreatic ductal adenocarcinoma who were eligible to undergo pancreaticoduodenectomy were enrolled. Study recruitment is complete, and follow-up is ongoing. This article reports prespecified early safety results from the trial. Interventions: Participants were randomized in a 1:1 ratio to undergo either laparoscopic or open pancreaticoduodenectomy, to be performed by experienced surgeons who had already performed at least 104 laparoscopic pancreaticoduodenectomy operations. Main Outcomes and Measures: The primary end point is 5-year overall survival, but the data for this end point are not yet mature; thus, secondary short-term outcomes, including operative findings, complications, mortality, and oncological results are reported here. The outcomes were analyzed according to a modified intention-to-treat and per-protocol principle. Results: Among 412 patients for eligibility, 200 patients were enrolled and randomly assigned 1:1 to have laparoscopic pancreaticoduodenectomy or open pancreaticoduodenectomy. The mean (SD) age was 61.3 (9.3) years, and 78 participants (39%) were female. Laparoscopic procedures had longer operative times (median [IQR], 330.0 [287.5-405.0] minutes vs 297.0 [245.0-340.0] minutes; P < .001). Patients in the laparoscopic group lost less blood than those in the open group (median [IQR], 145.0 [100.0-200.0] mL vs 200.0 [100.0-425.0] mL; P = .02). Ninety-day mortality occurred in 2 of 100 patients in the laparoscopic group and 0 of 100 patients in the open group. There was no difference in the rates of complications of the Clavien-Dindo grades III-IV (n = 17 [17.0%] vs n = 23 [23.0%]; P = .29), comprehensive complication index (median [IQR], 0.0 [0.0-22.6] vs 8.7 [0.0-26.2]; P = .79) or median (IQR) postoperative length of stay (14.0 [11.0-17.0] days vs 14.0 [12.0-18.5] days; P = .37) between the 2 groups. Conclusions and Relevance: Laparoscopic pancreaticoduodenectomy performed by experienced surgeons in high-volume specialized institutions resulted in similar short-term outcomes compared with open pancreaticoduodenectomy among patients with pancreatic ductal adenocarcinoma. Trial Registration: ClinicalTrials.gov Identifier: NCT03785743.

Nuclear receptor coactivator 6 (NCoA6) promotes cell proliferation, migration, and invasion in pancreatic cancer.

BACKGROUND: Nuclear receptor coactivator 6 (NCoA6) is overexpressed in various cancers and considered a multifunctional coactivator of various transcription factors and nuclear receptors. However, the role of NCoA6 in pancreatic ductal adenocarcinoma (PDAC) remains unclear. METHODS: NCoA6 expression data in PDAC were extracted from TCGA and GTEx databases, and their correlation with survival outcomes were analyzed using the Kaplan-Meier plotter database. NCoA6 protein expression in PDAC tissues was evaluated using immunohistochemistry. RNA-sequencing technology was used to sequence the transcriptome of NCoA6-silenced PANC-1 cells, followed by differential expression, GO/KEGG and GSEA analyses. The effects of NCoA6 on cell proliferation, migration, invasion, cell cycle, and apoptosis were determined in two representative cell lines (PANC-1 and SW1990). Western blotting, qPCR, and co-immunoprecipitation were performed to explore the mechanism of action of NCoA6 in PDAC cells. RESULTS: NCoA6 expression was markedly increased in PDAC tissues, and high NCoA6 expression was associated with poor survival prognosis. However, there was no significant relationship between NCoA6 expression and metastasis in PDAC patients. Our RNA-sequencing data analysis found 1194 significant differentially expressed genes between the control and NCoA6-silenced PANC-1 cells. GO/KEGG analysis results mainly focused on cytokine production, cytokine activity, and cytokine-cytokine receptor interactions. GSEA results showed that the knockdown of NCoA6 affected the expression of histone deacetylase 1 (HDAC1) targeted genes. NCoA6 knockdown suppressed proliferation, migration, and invasion of PDAC cells. Finally, western blotting, qPCR, and co-immunoprecipitation results showed that NCoA6 interacted with HDAC1 and that NCoA6 expression was negatively correlated with F-box and WD repeat domain-containing 7 (FBW7) and caudal-related homeobox transcription factor 2 (CDX2) expression in pancreatic cancer. CONCLUSIONS: NCoA6 has a profound effect on cell proliferation, migration, invasion, and prognosis of PDAC and is potentially related to the expression of HDAC1, FBW7, and CDX2. Our results may provide novel therapeutic strategies for PDAC patients.

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.

The Surgical and Therapeutic Activities of Non-Functional Pancreatic Neuroendocrine Tumors at a High-Volume Institution.

BACKGROUND: This study aimed to summarize the surgical and therapeutic activities of non-functional pancreatic neuroendocrine tumors (NF-PanNETs) and perform survival analyses of a 15-year single-institutional cohort of NF-PanNETs. METHODS: In total, 1001 patients with neuroendocrine neoplasms treated at Fudan University Shanghai Cancer Center were screened for inclusion, and 509 patients with NF-PanNETs from 2006 to 2020 were included. For time trend analyses, the 15-year study period was randomly divided into three periods. Survival analyses used the Kaplan-Meier method and Cox regression models. RESULTS: The total number of resected NF-PanNETs increased over the 15-year study period, from 5 resections in 2006 to 94 resections in 2020. A significant decrease in the tumor size was observed, from a mean of 4.0 cm to 3.3 cm, and to 3.0 cm in the most recent period (p = 0.006). Minimally invasive techniques gradually increased from 3.5% to 12.9%, and finally to 46.4% in the most recent period (p < 0.001). In non-metastatic and resected tumors, the tumor size (p < 0.001), positive lymph node (p < 0.001), adjuvant treatment (p = 0.048), and tumor grade (p < 0.001) were independent prognostic factors for recurrence-free survival (RFS). The microvascular invasion (p = 0.024) and tumor grade (p = 0.013) were independent prognostic factors for overall survival (OS). A malignant transformation from NET into neuroendocrine carcinoma was observed. CONCLUSIONS: An increasing number of NF-PanNETs resection and minimally invasive surgery was shown. In non-metastatic and resected tumors NF-PanNETs, tumor size, positive lymph node, adjuvant treatment, and tumor grade were independent predictors of RFS. Microvascular invasion and tumor grade were independent prognostic factors for OS.

A new glance at autophagolysosomal-dependent or -independent function of transcriptional factor EB in human cancer.

Autophagy-lysosome system plays a variety of roles in human cancers. In addition to being implicated in metabolism, it is also involved in tumor immunity, remodeling the tumor microenvironment, vascular proliferation, and promoting tumor progression and metastasis. Transcriptional factor EB (TFEB) is a major regulator of the autophagy-lysosomal system. With the in-depth studies on TFEB, researchers have found that it promotes various cancer phenotypes by regulating the autophagolysosomal system, and even in an autophagy-independent way. In this review, we summarize the recent findings about TFEB in various types of cancer (melanoma, pancreatic ductal adenocarcinoma, renal cell carcinoma, colorectal cancer, breast cancer, prostate cancer, ovarian cancer and lung cancer), and shed some light on the mechanisms by which it may serve as a potential target for cancer treatment.

Lactate-induced protein lactylation: A bridge between epigenetics and metabolic reprogramming in cancer.

Lactate is not only an endpoint of glycolysis but is gradually being discovered to play the role of a universal metabolic fuel for energy via the 'lactate shuttle' moving between cells and transmitting signals. The glycolytic-dependent metabolism found in tumours and fast-growing cells has made lactate a pivotal player in energy metabolism reprogramming, which enables cells to obtain abundant energy in a short time. Moreover, lactate can provide favourable conditions for tumorigenesis by shaping the acidic tumour microenvironment, recruiting immune cells, etc. and the recently discovered lactate-induced lactylation moves even further on pro-tumorigenesis mechanisms of lactate production, circulation and utilization. As with other epigenetic modifications, lactylation can modify histone proteins to alter the spatial configuration of chromatin, affect DNA accessibility and regulate the expression of corresponding genes. What's more, the degree of lactylation is inseparable from the spatialized lactate concentration, which builds a bridge between epigenetics and metabolic reprogramming. Here, we review the important role of lactate in energy reprogramming, summarize the latest finding of lactylation in tumorigenesis and try to explore therapeutic strategies in oncotherapy that can kill two birds with one stone.

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.

MEN1 Degradation Induced by Neddylation and the CUL4B-DCAF7 Axis Promotes Pancreatic Neuroendocrine Tumor Progression.

Pancreatic neuroendocrine tumors (PanNET) are a group of rare sporadic malignant tumors in the pancreas. MEN1 is the most frequently mutated gene in PanNETs. The MEN1-encoded protein is a typical tumor suppressor that forms a complex with epigenetic and transcription factors and is an attractive target for therapeutic interventions for patients with PanNET. A better understanding of the regulation of MEN1 protein expression in PanNETs could identify strategies for targeting MEN1. Here, we found that the neddylation pathway and DCAF7-mediated ubiquitination regulated MEN1 protein expression. Increased expression of members of the neddylation pathway and DCAF7 was found in PanNET tissues compared with paired-adjacent tissues and was associated with poor prognosis in patients with PanNET. Suppression of neddylation using the neddylation inhibitor MLN4924 or RNA interference significantly induced MEN1 accumulation and repressed cancer-related malignant phenotypes. CUL4B and DCAF7 promoted MEN1 degradation by binding and catalyzing its ubiquitination. In PanNET cells resistant to everolimus, a pharmacologic mTOR inhibitor widely used for advanced PanNET patient treatment, the downregulation of DCAF7 expression overcame resistance and synergized with everolimus to suppress mTOR activation and to inhibit cancer cell growth. The effects of DCAF7 loss could be counteracted by the simultaneous knockdown of MEN1 both in vitro and in vivo. The inverse correlation between DCAF7 and MEN1 was further validated in clinical specimens. This study revealed that the posttranslational control of MEN1 expression in PanNET is mediated by neddylation and the CUL4B-DCAF7 axis and identifies potential therapeutic targets in patients with MEN1-associated PanNET. SIGNIFICANCE: Identification of neddylation and ubiquitination pathways that regulate MEN1 protein stability provides an opportunity for therapeutic interventions for treating patients with pancreatic neuroendocrine tumors.