Clonal analysis of metachronous double biliary tract cancers.

The molecular mechanisms underpinning the development of metachronous tumors in the remnant bile duct following surgical resection of primary biliary tract carcinomas (BTCs) are unknown. This study aimed to elucidate these mechanisms by evaluating the clinicopathologic features of BTCs, the alterations to 31 BTC-related genes on targeted sequencing, and the aberrant expression of p53, p16, SMAD4, ARID1A and ß-catenin on immunohistochemistry. Twelve consecutive patients who underwent resection of metachronous BTCs following primary BTC resection with negative bile duct margins were enrolled. Among the 12 metachronous tumors, six exhibited anterograde growth in the lower portion and six exhibited retrograde growth in the upper portion of the biliary tree. Surgical resection of metachronous BTCs resulted in recurrence-free survival in seven, local recurrence in five, and death in two patients. Nine achieved 5-year overall survival after primary surgery. Molecular analyses revealed that recurrently altered genes were: TP53, SMAD4, CDKN2A, ELF3, ARID1A, GNAS, NF1, STK11, RNF43, KMT2D and ERBB3. Each of these was altered in at least three cases. A comparison of the molecular features between 12 paired primary and metachronous BTCs indicated that 10 (83%) metachronous tumors developed in clonal association with corresponding primary tumors either successionally or phylogenically. The remaining two (17%) developed distinctly. The successional tumors consisted of direct or evolved primary tumor clones that spread along the bile duct. The phylogenic tumors consisted of genetically unstable clones and conferred a poor prognosis. Metachronous tumors distinct from their primaries harbored fewer mutations than successional and phylogenic tumors. In conclusion, over 80% of metachronous BTCs that develop following primary BTC resection are probably molecularly associated with their primaries in either a successional or a phylogenetic manner. Comparison between the molecular features of a metachronous tumor and those of a preceding tumor may provide effective therapeutic clues for the treatment of metachronous BTC. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

A Runx1-enhancer Element eR1 Identified Lineage Restricted Mammary Luminal Stem Cells.

Mammary gland homeostasis is maintained by adult tissue stem-progenitor cells residing within the luminal and basal epithelia. Dysregulation of mammary stem cells is a key mechanism for cancer development. However, stem cell characterization is challenging because reporter models using cell-specific promoters do not fully recapitulate the mammary stem cell populations. We previously found that a 270-basepair Runx1 enhancer element, named eR1, marked stem cells in the blood and stomach. Here, we identified eR1 activity in a rare subpopulation of the ERα-negative luminal epithelium in mouse mammary glands. Lineage-tracing using an eR1-CreERT2 mouse model revealed that eR1+ luminal cells generated the entire luminal lineage and milk-secreting alveoli-eR1 therefore specifically marks lineage-restricted luminal stem cells. eR1-targeted-conditional knockout of Runx1 led to the expansion of luminal epithelial cells, accompanied by elevated ERα expression. Our findings demonstrate a definitive role for Runx1 in the regulation of the eR1-positive luminal stem cell proliferation during mammary homeostasis. Our findings identify a mechanistic link for Runx1 in stem cell proliferation and its dysregulation in breast cancer. Runx1 inactivation is therefore likely to be an early hit in the cell-of-origin of ERα+ luminal type breast cancer.

Reduced expression of phosphorylated ataxia-telangiectasia mutated gene is related to poor prognosis and gemcitabine chemoresistance in pancreatic cancer.

BACKGROUND: Loss of expression of the gene ataxia-telangiectasia mutated (ATM), occurring in patients with multiple primary malignancies, including pancreatic cancer, is associated with poor prognosis. In this study, we investigated the detailed molecular mechanism through which ATM expression affects the prognosis of patients with pancreatic cancer. METHODS: The levels of expression of ATM and phosphorylated ATM in patients with pancreatic cancer who had undergone surgical resection were analyzed using immunohistochemistry staining. RNA sequencing was performed on ATM-knockdown pancreatic-cancer cells to elucidate the mechanism underlying the invlovement of ATM in pancreatic cancer. RESULTS: Immunohistochemical analysis showed that 15.3% and 27.8% of clinical samples had low levels of ATM and phosphorylated ATM, respectively. Low expression of phosphorylated ATM substantially reduced overall and disease-free survival in patients with pancreatic cancer. In the pancreatic cancer cell lines with ATM low expression, resistance to gemcitabine was demonstrated. The RNA sequence demonstrated that ATM knockdown induced the expression of MET and NTN1. In ATM knockdown cells, it was also revealed that the protein expression levels of HIF-1α and antiapoptotic BCL-2/BAD were upregulated. CONCLUSIONS: These findings demonstrate that loss of ATM expression increases tumor development, suppresses apoptosis, and reduces gemcitabine sensitivity. Additionally, loss of phosphorylated ATM is associated with a poor prognosis in patients with pancreatic cancer. Thus, phosphorylated ATM could be a possible target for pancreatic cancer treatment as well as a molecular marker to track patient prognosis.

Negative prognostic impact of sarcopenia before and after neoadjuvant chemotherapy for pancreatic cancer.

OBJECTIVES: To elucidate the prognostic impact of sarcopenia before and after neoadjuvant chemotherapy (NAC) for pancreatic cancer (PC). METHODS: We retrospectively studied 75 consecutive PC patients who underwent neoadjuvant gemcitabine plus S-1 combination therapy followed by pancreatectomy between 2008 and 2016. According to the skeletal muscle volume index (SMI), the patients were divided into the muscle attenuation group (MAG) and normal group (NG) before or after NAC. Prognostic factors for overall survival (OS) were analyzed by Cox proportional hazards models. RESULTS: The MAG showed significantly poorer OS than the NG before and after NAC. Pre-NAC, median OS was 20.0 months in the MAG versus 49.0 months in the NG (p = 0.006). Post-NAC, median OS was 21.3 months in the MAG versus 48.8 months in the NG (p = 0.014). Multivariate analysis, excluding muscle attenuation after NAC because of confounding factors and lower hazard ratio (2.08, 95% confidence interval: 1.14-3.78, p = 0.016) than that before NAC (2.14, 1.23-3.70, p = 0.007) by univariate analysis, revealed the following independent prognostic factors: muscle attenuation pre-NAC (2.25, 1.26-4.05, p = 0.007); borderline resectability (1.96, 1.04-3.69, p = 0.038); operative blood loss (2.60, 1.38-4.88, p = 0.003); and distant metastasis (3.31, 1.40-7.82, p = 0.006). CONCLUSIONS: Sarcopenia before and after NAC for PC is suggested to be a poor prognostic factor, with a stronger impact before than after NAC.

Chronic Glucocorticoid Use is a Potential Risk Factor for Delayed Pancreatic Fistula after Laparoscopic Distal Pancreatectomy: A Retrospective Analysis.

Pancreatic fistula is a potentially morbid complication after distal pancreatectomy. Chronic glucocorticoid use is one of the risk factors for pancreatic fistula in pancreaticoduodenectomy, though it has not been reported in distal pancreatectomy. We explored whether chronic glucocorticoid use can be a risk factor for pancreatic fistula in distal pancreatectomy. We reviewed 408 consecutive patients who underwent elective distal pancreatectomy from 2011 to 2021. We evaluated two kinds of pancreatic fistula (postoperative pancreatic fistula and delayed pancreatic fistula). We defined delayed pancreatic fistula as a patient who was re-admitted for pancreatic fistula after the first discharge from the hospital. Preoperative characteristics and postoperative outcomes were analyzed. Two hundred sixty-seven patients underwent open distal pancreatectomy, while 141 patients had laparoscopic distal pancreatectomy. A comparison of patient with and without chronic glucocorticoid use showed that only patients with chronic glucocorticoid use developed delayed pancreatic fistula (0% vs. 16.7%; p < 0.001). In addition, delayed pancreatic fistula occurred in only laparoscopic distal pancreatectomy patients with chronic glucocorticoid use (0% vs. 25.0%; p < 0.001). Although sample size is small, it is reasonable to presume that chronic glucocorticoid use is a potential risk factor for delayed pancreatic fistula in laparoscopic distal pancreatectomy.

[A Case of an Elderly Patient Who Underwent Conversion Resection for Pancreatic Cancer with Positive Peritoneal Cytology].

We report a case of an elderly patient, 82 years-old, with initially-unresectable pancreatic head cancer, who successfully underwent complete resection of the primary lesion after systemic chemotherapy for 6 months. The patient had a history of pancreatic body-tail resection for intraductal papillary mucinous carcinoma in 2005. In 2020, a routine examination revealed an increased CA19-9 value of 1,958 U/mL and showed a pancreatic head tumor of 35 mm on CT images. Finally, the tumor was pathologically diagnosed as pancreatic cancer by a biopsied sample. Although CT images showed no distant metastasis, peritoneal lavage cytology was indicated as positivity(H0P0CY1)in the staging laparoscopy. We implanted a peritoneal port and introduced systemic chemotherapy of gemcitabine and nab-paclitaxel combination therapy. This treatment for 6 months induced tumor shrinkage to 30 mm on the CT image, normalized CA19-9 value to 22.6 U/mL, and negative cytology in the collected lavage fluid from the peritoneal port. The patient's general condition was maintained even after the chemotherapy and the lavage cytology was pathologically diagnosed as negative(H0P0CY0)in the repeated staging laparoscopy, therefore we decided to perform pancreaticoduodenectomy as a conversion surgery. The patient was discharged on the 21st postoperative day with an uneventful course and underwent adjuvant chemotherapy of S-1 for 6 months. No recurrence was found in 8 months after the surgery. In such a case of the selected elderly patient with a maintained general condition, it is feasible to undergo multimodal treatments including conversion surgery for an initially-unresectable pancreatic cancer with positive peritoneal cytology.

Induction of Gastric Cancer by Successive Oncogenic Activation in the Corpus.

BACKGROUND & AIMS: Metaplasia and dysplasia in the corpus are reportedly derived from de-differentiation of chief cells. However, the cellular origin of metaplasia and cancer remained uncertain. Therefore, we investigated whether pepsinogen C (PGC) transcript-expressing cells represent the cellular origin of metaplasia and cancer using a novel Pgc-specific CreERT2 recombinase mouse model. METHODS: We generated a Pgc-mCherry-IRES-CreERT2 (Pgc-CreERT2) knock-in mouse model. Pgc-CreERT2/+ and Rosa-EYFP mice were crossed to generate Pgc-CreERT2/Rosa-EYFP (Pgc-CreERT2/YFP) mice. Gastric tissues were collected, followed by lineage-tracing experiments and histologic and immunofluorescence staining. We further established Pgc-CreERT2;KrasG12D/+ mice and investigated whether PGC transcript-expressing cells are responsible for the precancerous state in gastric glands. To investigate cancer development from PGC transcript-expressing cells with activated Kras, inactivated Apc, and Trp53 signaling pathways, we crossed Pgc-CreERT2/+ mice with conditional KrasG12D, Apcflox, Trp53flox mice. RESULTS: Expectedly, mCherry mainly labeled chief cells in the Pgc-CreERT2 mice. However, mCherry was also detected throughout the neck cell and isthmal stem/progenitor regions, albeit at lower levels. In the Pgc-CreERT2;KrasG12D/+ mice, PGC transcript-expressing cells with KrasG12D/+ mutation presented pseudopyloric metaplasia. The early induction of proliferation at the isthmus may reflect the ability of isthmal progenitors to react rapidly to Pgc-driven KrasG12D/+ oncogenic mutation. Furthermore, Pgc-CreERT2;KrasG12D/+;Apcflox/flox mice presented intramucosal dysplasia/carcinoma and Pgc-CreERT2;KrasG12D/+;Apcflox/flox;Trp53flox/flox mice presented invasive and metastatic gastric carcinoma. CONCLUSIONS: The Pgc-CreERT2 knock-in mouse is an invaluable tool to study the effects of successive oncogenic activation in the mouse corpus. Time-course observations can be made regarding the responses of isthmal and chief cells to oncogenic insults. We can observe stomach-specific tumorigenesis from the beginning to metastatic development.

Iqgap3-Ras axis drives stem cell proliferation in the stomach corpus during homoeostasis and repair.

OBJECTIVE: Tissue stem cells are central regulators of organ homoeostasis. We looked for a protein that is exclusively expressed and functionally involved in stem cell activity in rapidly proliferating isthmus stem cells in the stomach corpus. DESIGN: We uncovered the specific expression of Iqgap3 in proliferating isthmus stem cells through immunofluorescence and in situ hybridisation. We performed lineage tracing and transcriptomic analysis of Iqgap3 +isthmus stem cells with the Iqgap3-2A-tdTomato mouse model. Depletion of Iqgap3 revealed its functional importance in maintenance and proliferation of stem cells. We further studied Iqgap3 expression and the associated gene expression changes during tissue repair after tamoxifen-induced damage. Immunohistochemistry revealed elevated expression of Iqgap3 in proliferating regions of gastric tumours from patient samples. RESULTS: Iqgap3 is a highly specific marker of proliferating isthmus stem cells during homoeostasis. Iqgap3+isthmus stem cells give rise to major cell types of the corpus unit. Iqgap3 expression is essential for the maintenance of stem potential. The Ras pathway is a critical partner of Iqgap3 in promoting strong proliferation in isthmus stem cells. The robust induction of Iqgap3 expression following tissue damage indicates an active role for Iqgap3 in tissue regeneration. CONCLUSION: IQGAP3 is a major regulator of stomach epithelial tissue homoeostasis and repair. The upregulation of IQGAP3 in gastric cancer suggests that IQGAP3 plays an important role in cancer cell proliferation.

Silencing of LRRFIP1 enhances the sensitivity of gemcitabine in pancreatic cancer cells by activating JNK/c-Jun signaling.

BACKGROUND: The epithelial-mesenchymal transition (EMT) in cancer cells has been shown to closely associate with the survival and drug resistance of cancer cells. We recently provided evidence that Wnt signal activator leucine-rich repeat in flightless-1-interacting protein 1 (LRRFIP1) regulates EMT in pancreatic cancer. LRRFIP1 silencing inhibits the translocation of ß-catenin to the nucleus, which led to reverse EMT in cancer cells. It was suggested that LRRFIP1 was implicated in gemcitabine sensitivity by regulating EMT signaling. METHODS: Gemcitabine chemosensitivity was investigated in LRRFIP1-knockdown pancreatic cancer cells (PANC-1 and MIA Paca-2). In addition, the effects of LRRFIP1 knockdown on JNK/SAPK (stress activated-protein kinase) signaling and apoptosis were evaluated. RESULTS: LRRFIP1 silencing accelerates gemcitabine-induced caspase activity and cell death in pancreatic cancer cells. It was also revealed that gemcitabine-induced phosphorylation of c-Jun N-terminal kinase (JNK) and c-Jun were increased in LRRFIP1 knockdown cells. The activation of JNK/c-Jun in LRRFIP1-knockdown cells was significantly diminished by the inhibition of Rac activity. It was confirmed that the acquisition of gemcitabine sensitivity by LRRFIP1 silencing largely depends on the stimulation of JNK/SAPK (stress activated-protein kinase) signaling. CONCLUSIONS: Our findings suggest that reversing EMT and transient activation of JNK might be essential for the gemcitabine sensitivity in LRRFIP1 knockdown pancreatic cancer cells. Our discoveries highlight the potential role of LRRFIP1 in the chemosensitivity related to the regulation of EMT signaling.

Optimal timing of cholecystectomy after percutaneous gallbladder drainage for severe cholecystitis.

BACKGROUND: The Tokyo guideline for acute cholecystitis recommended percutaneous transhepatic gallbladder drainage followed by cholecystectomy for severe acute cholecystitis, but the optimal timing for the subsequent cholecystectomy remains controversial. METHODS: Sixty-seven patients who underwent either laparoscopic or open cholecystectomy after percutaneous transhepatic gallbladder drainage for severe acute cholecystitis were enrolled and divided into difficult cholecystectomy (group A) and non-difficult cholecystectomy (group B). Patients who had one of these conditions were placed in group A: 1) conversion from laparoscopic to open cholecystectomy; 2) subtotal cholecystectomy and/or mucoclasis; 3) necrotizing cholecystitis or pericholecystic abscess formation; 4) tight adhesions around the gallbladder neck; and 5) unsuccessfully treated using PTGBD. Preoperative characteristics and postoperative outcomes were analyzed. RESULTS: The interval between percutaneous transhepatic gallbladder drainage and cholecystectomy in Group B was longer than that in Group A (631 h vs. 325 h; p = 0.031). Postoperative complications occurred more frequently when the interval was less than 216 h compared to when it was more than 216 h (35.7 vs. 7.6%; p = 0.006). CONCLUSIONS: Cholecystectomy for severe acute cholecystitis was technically difficult when performed within 216 h after percutaneous transhepatic gallbladder drainage.

Risk factors for difficulty of laparoscopic cholecystectomy in grade II acute cholecystitis according to the Tokyo guidelines 2013.

BACKGROUND: The Tokyo Guidelines 2013 classifies acute cholecystitis (AC) into three grades and recommends appropriate therapy for each grade. For grade II AC, either early laparoscopic cholecystectomy (LC) or percutaneous transhepatic gallbladder drainage (PTGBD) should be performed. This study aimed to identify the risk factors for difficulty of LC for treating grade II AC. METHODS: Totally, 122 patients who underwent LC for grade II AC were enrolled and divided into difficult LC (DLC) and nondifficult LC (NDLC) groups. The DLC group included patients who experienced one of the following conditions: conversion from LC to open cholecystectomy, operating time ≥ 180 min, or blood loss ≥300 ml. Preoperative characteristics and postoperative outcomes were analyzed. RESULTS: In univariate analysis, risk factors included male sex, interval between symptom onset and admission, interval between symptom onset and LC, and anticoagulant therapy. The incidence of postoperative complications was higher in the DLC group than in the NDLC group (23.5% vs. 4.6%, p = 0.0016). According to receiver operating characteristic curves, the optimal cutoff value was calculated, and multivariate analysis showed that male sex [odds ratio (OR), 5.76; 95% confidence interval (CI), 1.979-19.51; p = 0.0009) and interval between symptom onset and LC of over 96 h (OR, 6.32; 95% CI, 2.126-20.15; p = 0.0009) were independent risk factors for difficulty of LC. CONCLUSIONS: In patients with grade II AC, LC was technically difficult when performed over 96 h after symptom onset. Moreover, male sex was a risk factor. Therefore, PTGBD should be considered in these patients.

GFPT2 expression is induced by gemcitabine administration and enhances invasion by activating the hexosamine biosynthetic pathway in pancreatic cancer.

Our previous studies revealed a novel link between gemcitabine (GEM) chemotherapy and elevated glutamine-fructose-6-phosphate transaminase 2 (GFPT2) expression in pancreatic cancer (PaCa) cells. GFPT2 is a rate-limiting enzyme in the hexosamine biosynthesis pathway (HBP). HBP can enhance metastatic potential by regulating epithelial-mesenchymal transition (EMT). The aim of this study was to further evaluate the effect of chemotherapy-induced GFPT2 expression on metastatic potential. GFPT2 expression was evaluated in a mouse xenograft model following GEM exposure and in clinical specimens of patients after chemotherapy using immunohistochemical analysis. The roles of GFPT2 in HBP activation, downstream pathways, and cellular functions in PaCa cells with regulated GFPT2 expression were investigated. GEM exposure increased GFPT2 expression in tumors resected from a mouse xenograft model and in patients treated with neoadjuvant chemotherapy (NAC). GFPT2 expression was correlated with post-operative liver metastasis after NAC. Its expression activated the HBP, promoting migration and invasion. Treatment with HBP inhibitors reversed these effects. Additionally, GFPT2 upregulated ZEB1 and vimentin expression and downregulated E-cadherin expression. GEM induction upregulated GFPT2 expression. Elevated GFPT2 levels promoted invasion by activating the HBP, suggesting the potential role of this mechanism in promoting chemotherapy-induced metastasis.

RUNX3 in Stem Cell and Cancer Biology.

The runt-related transcription factors (RUNX) play prominent roles in cell cycle progression, differentiation, apoptosis, immunity and epithelial-mesenchymal transition. There are three members in the mammalian RUNX family, each with distinct tissue expression profiles. RUNX genes play unique and redundant roles during development and adult tissue homeostasis. The ability of RUNX proteins to influence signaling pathways, such as Wnt, TGFß and Hippo-YAP, suggests that they integrate signals from the environment to dictate cell fate decisions. All RUNX genes hold master regulator roles, albeit in different tissues, and all have been implicated in cancer. Paradoxically, RUNX genes exert tumor suppressive and oncogenic functions, depending on tumor type and stage. Unlike RUNX1 and 2, the role of RUNX3 in stem cells is poorly understood. A recent study using cancer-derived RUNX3 mutation R122C revealed a gatekeeper role for RUNX3 in gastric epithelial stem cell homeostasis. The corpora of RUNX3R122C/R122C mice showed a dramatic increase in proliferating stem cells as well as inhibition of differentiation. Tellingly, RUNX3R122C/R122C mice also exhibited a precancerous phenotype. This review focuses on the impact of RUNX3 dysregulation on (1) stem cell fate and (2) the molecular mechanisms underpinning early carcinogenesis.

Identifying Adult Stomach Tissue Stem/Progenitor Cells Using the Iqgap3-2A-CreERT2 Mouse.

Identification of unique gene markers of normal and cancer stem cells is an effective strategy to study cells of origin and understand tumor behavior. Lineage tracing experiments using the Cre recombinase driven by a stem cell-specific promoter in the CreERT2 reporter mouse model enables identification of adult stem cells and delineation of stem cell activities in vivo. In our recent research on the mouse stomach, Iqgap3 was identified as a homeostatic stem cell marker located in the isthmus of the stomach epithelium. Lineage tracing with the Iqgap3-2A-CreERT2;Rosa26-LSL-tdTomato mouse model demonstrated stem cell activity in Iqgap3-expressing cells. Using the Iqgap3-2A-CreERT2 mouse model to target oncogenic KrasG12D expression to Iqgap3-expressing cells, we observed the rapid development of precancerous metaplasia in the stomach and proposed that aberrant Iqgap3-expressing cells may be critical determinants of early carcinogenesis. In this chapter, we detail a lineage tracing protocol to assess stem cell activity in the murine stomach. We also describe the procedure of inducing KrasG12D expression in Iqgap3-expressing homeostatic stem cells to explore their role as cells of origin and to trace the early cellular changes that precede neoplastic transformation.

CA19-9 With Two-stage Resection Is Useful for Conversion Surgery in PDAC With Synchronous Oligometastases.

BACKGROUND/AIM: Pancreatic adenocarcinoma (PDAC) with synchronous oligometastases may indicate a surgical benefit after chemotherapy. We investigated whether primary and metastatic resection of PDAC with oligometastases can improve the survival and then explored prognostic factors to identify indications for conversion surgery. PATIENTS AND METHODS: We reviewed 425 patients with PDAC who underwent pancreatic resection from 2005 to 2019. Clinical characteristics and outcomes were analyzed. Two-stage resection was defined as preceding metastasectomy and subsequent primary resection after chemotherapy. RESULTS: Fifteen patients (3.5%) had synchronous oligometastases. We evaluated the overall survival of the patients with oligometastases and those without metastases. The survival curves almost completely overlapped (median survival time: 35.9 vs. 32.1 months). The univariate Cox regression analysis revealed a normal level of preoperative CA19-9 (p=0.075), two-stage resection (p=0.072), and R0 resection (p=0.064) were likely promising prognostic factors. The combination of a normal level of preoperative CA19-9 with two-stage resection was a significant prognostic factor (p=0.038). In addition, patients with a normal preoperative CA19-9 level and two-stage resection had better survival (46.1 vs. 28.1 months, p=0.026). CONCLUSION: The combination of normal preoperative CA19-9 with two-stage resection can be a useful way to identify patients with PDAC and oligometastases for surgical indication.

A Point Mutation R122C in RUNX3 Promotes the Expansion of Isthmus Stem Cells and Inhibits Their Differentiation in the Stomach.

BACKGROUND & AIMS: RUNX transcription factors play pivotal roles in embryonic development and neoplasia. We previously identified the single missense mutation R122C in RUNX3 from human gastric cancer. However, how RUNX3R122C mutation disrupts stem cell homeostasis and promotes gastric carcinogenesis remained unclear. METHODS: To understand the oncogenic nature of this mutation in vivo, we generated the RUNX3R122C knock-in mice. Stomach tissues were harvested, followed by histologic and immunofluorescence staining, organoid culture, flow cytometry to isolate gastric corpus isthmus and nonisthmus epithelial cells, and RNA extraction for transcriptomic analysis. RESULTS: The corpus tissue of RUNX3R122C/R122C homozygous mice showed a precancerous phenotype such as spasmolytic polypeptide-expressing metaplasia. We observed mucous neck cell hyperplasia; massive reduction of pit, parietal, and chief cell populations; as well as a dramatic increase in the number of rapidly proliferating isthmus stem/progenitor cells in the corpus of RUNX3R122C/R122C mice. Transcriptomic analyses of the isolated epithelial cells showed that the cell-cycle-related MYC target gene signature was enriched in the corpus epithelial cells of RUNX3R122C/R122C mice compared with the wild-type corpus. Mechanistically, RUNX3R122C mutant protein disrupted the regulation of the restriction point where cells decide to enter either a proliferative or quiescent state, thereby driving stem cell expansion and limiting the ability of cells to terminally differentiate. CONCLUSIONS: RUNX3R122C missense mutation is associated with the continuous cycling of isthmus stem/progenitor cells, maturation arrest, and development of a precancerous state. This work highlights the importance of RUNX3 in the prevention of metaplasia and gastric cancer.

Extreme dilatation of the interposed jejunal pouch after proximal gastrectomy associated with portal venous gas: A case report.

INTRODUCTION: The jejunal pouch interposition (JPI) after proximal gastrectomy (PG) was proposed as a reconstructive procedure to provide a gastric reservoir substitute and prevent postgastrectomy syndrome. However, food residue remaining in some of the pouches resulted in the adverse effect of abdominal bloating, thereby body weight loss. Here, we report a rare case with an extreme dilation of the interposed jejunal pouch (JP) 8 years after PG, requiring pouch resection. PRESENTATION OF CASE: A 65-year-old-man who had undergone PG with an inverted U-shaped JPI for early gastric cancer 8 years previously, suffered from shock after right hip joint implantation. Abdominal enhanced CT scan revealed an extremely dilated JP accompanied by portal venous gas. After 5 months of conservative therapy, he underwent resection of the JP and gastric remnant with Roux-en-Y esophagojejunostomy reconstruction. After the operation, the patient has remained in good health for over 3 years. DISCUSSION AND CONCLUSION: Long-term operative outcome following pouch operation for gastric cancer still remains controversial. Surgical intervention should be considered when we encounter patients who have refractory pouch dilatation after surgery for gastric cancer.

MK2461, a Multitargeted Kinase Inhibitor, Suppresses the Progression of Pancreatic Cancer by Disrupting the Interaction Between Pancreatic Cancer Cells and Stellate Cells.

OBJECTIVES: Platelet-derived growth factor receptor beta (PDGFRß) and hepatocyte growth factor receptor (MET) expressed on pancreatic stellate cells (PSCs) are suggested as important components modulating the interactions between pancreatic cancer cells (PCCs) and PSCs. The objective of this study is to clarify the effect of MK2461, a multikinase inhibitor targeting MET and PDGFRß, on the interaction between PCCs and PSCs. METHODS: In this study, we profiled the expression of receptor tyrosine kinases (including PDGFRß and MET) in pancreatic cancer with quantitative targeted absolute proteomics using liquid chromatography tandem mass spectrometry. In addition, the effect of MK2461 on PCC-PSC interaction was investigated using PSCs prepared from pancreatic cancer tissues. RESULTS: In PSCs, PDGFRß and MET were upregulated compared with other receptor tyrosine kinases. Conditioned medium from PSCs promoted the proliferation of PCCs, and vice versa. Moreover, MK2461 suppressed the effects of conditioned medium on PCCs and PSCs. Finally, MK2461 significantly inhibited tumor growth in mice coinjected with PCCs and PSCs. CONCLUSIONS: The PDGFRß and MET may play a critical role in the interaction between PCCs and PSCs, which was modulated by MK2461. Therefore, MK2461 may have therapeutic potential in the treatment of pancreatic cancer.

Silencing of LRRFIP1 reverses the epithelial-mesenchymal transition via inhibition of the Wnt/ß-catenin signaling pathway.

The canonical Wnt/ß-catenin signaling pathway has been shown to promote the epithelial-mesenchymal transition (EMT), which is a crucial process in multiple embryonic developmental processes and the progression of carcinomas. We recently provided evidence that leucine-rich repeat flightless-1-interacting protein 1 (LRRFIP1) promotes cancer metastasis and invasion. In the present study, we identified the signaling elements targeted by LRRFIP1 for promotion of the EMT in pancreatic and lung cancer. LRRFIP1 silencing reversed the EMT, as shown by increased expression of E-cadherin (an epithelial marker) and decreased expression of vimentin (a mesenchymal marker). Silencing of LRRFIP1 up-regulated phosphorylation of ß-catenin and decreased its nuclear localization by targeting the ß-catenin destruction complex. The expression of ß-catenin and E-cadherin in the plasma membrane fraction was increased in LRRFIP1 silenced cancer cells, and the migration and invasion capabilities were strongly inhibited. In addition, this protein was highly expressed at the invasion front of malignant tissue collected from pancreatic cancer patients. Consequently, our data strongly suggested that LRRFIP1 played an important role in the invasion of carcinoma cells. Our data provide experimental evidence that LRRFIP1 is an attractive candidate for targeted therapy in human cancers.

GCF2/LRRFIP1 promotes colorectal cancer metastasis and liver invasion through integrin-dependent RhoA activation.

The precise relationship between GCF2 expression and carcinogenesis has not yet been established. To clarify the metastatic potential of GCF2 in colorectal cancer, HT-29 cells stably suppressing GCF2 expression were injected into the spleens of severe combined immunodeficient (SCID) mice. GCF2 suppression reduced the number of metastatic foci in the liver and reduced fibronectin-induced cell adhesion, migration, and invasion. Downstream from the integrin signaling pathways, GCF2 regulates RhoA interaction with the RGS domain of Leukemia associated RhoGEF (LARG). Altogether, our results suggest that GCF2 plays an important role in colorectal cancer metastasis by regulating RhoA-induced cell adhesion, migration, and invasion.