Search

Background: The results of laparoscopic pancreaticoduodenectomy combining with mesentericoportal vein resection and reconstruction (LPD-MPVRs) for pancreatic head adenocarcinoma are rarely reported. The aim of present study was to explore the short- and long-term outcomes of different type of LPD-MPVRs. Methods: Patients who underwent LPD-MPVRs in 14 Chinese high-volume pancreatic centers between June 2014 and December 2020 were selected and compared. Results: In total, 142 patients were included and were divided into primary closure (n= 56), end-end anastomosis (n= 43), or interposition graft (n= 43). Median overall survival (OS) and median progress-free survival (PFS) between primary closure and end-end anastomosis had no difference (both P> 0.05). As compared to primary closure and end-end anastomosis, interposition graft had the worst median OS (12 months versus 19 months versus 17 months, P= 0.001) and the worst median PFS (6 months versus 15 months versus 12 months, P< 0.000). As compared to primary closure, interposition graft had almost double risk in major morbidity (16.3 percent versus 8.9 percent) and about triple risk (10 percent versus 3.6 percent) in 90-day mortality, while End-end anastomosis had only one fourth major morbidity (2.3 percent versus 8.9 percent). Multivariate analysis revealed postoperation hospital stay, American Society of Anesthesiologists (ASA) score, number of positive lymph nodes had negative impact on OS, while R0, R1 surgical margin had protective effect on OS. Postoperative hospital stay had negative impact on PFS, while primary closure, end-end anastomosis, short-term vascular patency, and short-term vascular stenosis positively related to PFS. Conclusions: In LPD-MPVRs, interposition graft had the worst OS, the worst PFS, the highest rate of major morbidity, and the highest rate of 90-day mortality. While there were no differences in OS and PFS between primary closure and end-end anastomosis.

C-Myc overexpression contributes to multiple hallmarks of human cancer but directly targeting c-Myc is challenging. Identification of key factors involved in c-Myc dysregulation is of great significance to develop potential indirect targets for c-Myc. Herein, a collection of long non-coding RNAs (lncRNAs) interacted with c-Myc is detected in pancreatic ductal adenocarcinoma (PDAC) cells. Among them, lncRNA BCAN-AS1is identified as the one with highest c-Myc binding enrichment. BCAN-AS1was abnormally elevated in PDAC tumors and high BCAN-AS1level was significantly associated with poor prognosis. Mechanistically, Smad nuclear-interacting protein 1 (SNIP1) was characterized as a new N6-methyladenosine (m6A) mediator binding to BCAN-AS1via recognizing its m6A modification. m6A-modified BCAN-AS1acts as a scaffold to facilitate the formation of a ternary complex together with c-Myc and SNIP1, thereby blocking S phase kinase-associated protein 2 (SKP2)-mediated c-Myc ubiquitination and degradation. Biologically, BCAN-AS1promotes malignant phenotypes of PDAC in vitro and in vivo. Treatment of metastasis xenograft and patient-derived xenograft mouse models with in vivo-optimized antisense oligonucleotide of BCAN-AS1effectively represses tumor growth and metastasis. These findings shed light on the pro-tumorigenic role of BCAN-AS1and provide an innovant insight into c-Myc-interacted lncRNA in PDAC.

The biological functions of noncoding RNA N6-methyladenosine (m6A) modification remain poorly understood. In the present study, we depict the landscape of super-enhancer RNA (seRNA) m6A modification in pancreatic ductal adenocarcinoma (PDAC) and reveal a regulatory axis of m6A seRNA, H3K4me3 modification, chromatin accessibility and oncogene transcription. We demonstrate the cofilin family protein CFL1, overexpressed in PDAC, as a METTL3 cofactor that helps seRNA m6A methylation formation. The increased seRNA m6As are recognized by the reader YTHDC2, which recruits H3K4 methyltransferase MLL1 to promote H3K4me3 modification cotranscriptionally. Super-enhancers with a high level of H3K4me3 augment chromatin accessibility and facilitate oncogene transcription. Collectively, these results shed light on a CFL1–METTL3–seRNA m6A–YTHDC2/MLL1 axis that plays a role in the epigenetic regulation of local chromatin state and gene expression, which strengthens our knowledge about the functions of super-enhancers and their transcripts.

Perineural invasion (PNI) is a biological characteristic commonly observed in pancreatic cancer. Although PNI plays a key role in pancreatic cancer metastasis, recurrence, and poor postoperative survival, its mechanism is largely unclarified. Clinical sample analysis and endoscopic ultrasonographic elasticity scoring indicated that cancer-associated fibroblasts (CAFs) were closely related to the occurrence of PNI. Furthermore, CAF-derived extracellular vesicles (EVs) were involved in PNI in dorsal root ganglion coculture and mouse sciatic nerve models. Next, we demonstrated that CAFs promoted PNI through extracellular vesicle transmission of PNI-associated transcript (PIAT). Mechanistically, PIAT specifically bound to YBX1 and blocked the YBX1-Nedd4l interaction to inhibit YBX1 ubiquitination and degradation. Furthermore, PIAT enhanced the binding of YBX1 and PNI-associated mRNAs in a 5-methylcytosine (m5C)–dependent manner. Mutation of m5C recognition motifs in YBX1 or m5C sites in downstream target genes reversed PIAT-mediated PNI. Consistent with these findings, analyses using a KPC mouse model demonstrated that the PIAT/YBX1 axis enhanced PNI through m5C modification. Clinical data suggested that the PIAT expression in the serum EVs of patients with pancreatic cancer was associated with the degree of neural invasion and prognosis. Our study revealed the important role of the PIAT/YBX1 signaling axis in the tumor microenvironment (TME) in promoting tumor cell PNI and provided a new target for precise interference with CAFs and RNA methylation in the TME to suppress PNI in pancreatic cancer.

The tumor stroma of pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundant and heterogeneous population of cancer-associated fibroblasts (CAFs), which are critically involved in chemoresistance. However, the underlying mechanism of CAFs in chemoresistance is unclear. Here, we show that CAFR, a CAF subset derived from platinum-resistant PDAC patients, assumes an iCAF phenotype and produces more IL8 than CAFSisolated from platinum-sensitive PDAC patients. CAFR-derived IL8 promotes oxaliplatin chemoresistance in PDAC. Based on long noncoding RNA (lncRNA) profiling in tumor cells incubated with CAF-CM, we found that UPK1A-AS1, whose expression is directly induced by IL8/NF-kappa B signaling, functions as a chemoresistance-promoting lncRNA and is critical for active IL8-induced oxaliplatin resistance. Impressively, blocking the activation of UPK1A-AS1 expression increases the oxaliplatin sensitivity of tumor cells in vivo. Mechanistically, UPK1A-AS1 strengthens the interaction between Ku70 and Ku80 to facilitate nonhomologous end joining (NHEJ), thereby enhancing DNA double-strand break (DSB) repair. Clinically, UPK1A-AS1 expression is positively correlated with IL8 expression, a poor chemotherapeutic response and a shorter progression-free survival (PFS) time in advanced PDAC patients. Collectively, our study reveals a lncRNA-mediated mechanism of CAF-derived paracrine IL8-dependent oxaliplatin resistance and highlights UPK1A-AS1 as a potential therapeutic target.

The benefit and safety of laparoscopic pancreatoduodenectomy (LPD) for the treatment of pancreatic or periampullary tumours remain controversial. Studies have shown that the learning curve plays an important role in LPD, yet there are no randomised studies on LPD after the surgeons have surmounted the learning curve. The aim of this trial was to compare the outcomes of open pancreatoduodenectomy (OPD) with those of LPD, when performed by experienced surgeons.

Supplemental Digital Content is available in the text