Downregulation of ABCC3 activates MAPK signaling through accumulation of deoxycholic acid in colorectal cancer cells.

ABCC3 (also known as MRP3) is an ATP binding cassette transporter for bile acids, whose expression is downregulated in colorectal cancer through the Wnt/ß-catenin signaling pathway. However, it remained unclear how downregulation of ABCC3 expression contributes to colorectal carcinogenesis. We explored the role of ABCC3 in the progression of colorectal cancer-in particular, focusing on the regulation of bile acid export. Gene expression analysis of colorectal adenoma isolated from familial adenomatous polyposis patients revealed that genes related to bile acid secretion including ABCC3 were downregulated as early as at the stage of adenoma formation. Knockdown or overexpression of ABCC3 increased or decreased intracellular concentration of deoxycholic acid, a secondary bile acid, respectively, in colorectal cancer cells. Forced expression of ABCC3 suppressed deoxycholic acid-induced activation of MAPK signaling. Finally, we found that nonsteroidal anti-inflammatory drugs increased ABCC3 expression in colorectal cancer cells, suggesting that ABCC3 could be one of the targets for therapeutic intervention of familial adenomatous polyposis. Our data thus suggest that downregulation of ABCC3 expression contributes to colorectal carcinogenesis through the regulation of intracellular accumulation of bile acids and activity of MAPK signaling.

The Mucus Binding Factor Is Not Necessary for Lacticaseibacillus rhamnosus CRL1505 to Exert Its Immunomodulatory Activities in Local and Distal Mucosal Sites.

Both viable and non-viable orally administered Lacticaseibacillus rhamnosus CRL1505 modulate immunity in local (intestine) and distal (respiratory) mucosal sites. So, intestinal adhesion and colonization are not necessary for this probiotic strain to exert its immunomodulatory effects. In this work, a mucus-binding factor knockout CRL1505 strain (ΔmbfCRL1505) was obtained and the lack of binding ability to both intestinal epithelial cells and mucin was demonstrated in vitro. In addition, two sets of in vivo experiments in 6-week-old Balb/c mice were performed to evaluate ΔmbfCRL1505 immunomodulatory activities. (A) Orally administered ΔmbfCRL1505 prior to intraperitoneal injection of the Toll-like receptor 3 (TLR3) agonist poly(I:C) significantly reduced intraepithelial lymphocytes (CD3+NK1.1+CD8αα+) and pro-inflammatory mediators (TNF-α, IL-6 and IL-15) in the intestinal mucosa. (B) Orally administered ΔmbfCRL1505 prior to nasal stimulation with poly(I:C) significantly decreased the levels of the biochemical markers of lung tissue damage. In addition, reduced recruitment of neutrophils and levels of pro-inflammatory mediators (TNF-α, IL-6 and IL-8) as well as increased IFN-ß and IFN-γ in the respiratory mucosa were observed in ΔmbfCRL1505-treated mice when compared to untreated control mice. The immunological changes induced by the ΔmbfCRL1505 strain were not different from those observed for the wild-type CRL1505 strain. Although it is generally accepted that the expression of adhesion factors is necessary for immunobiotics to induce their beneficial effects, it was demonstrated here that the mbf protein is not required for L. rhamnosus CRL1505 to exert its immunomodulatory activities in local and distal mucosal sites. These results are a step forward towards understanding the mechanisms involved in the immunomodulatory capabilities of L. rhamnosus CRL1505.

[A Case of Laparoscopic Abdominoperineal Resection and Perineal Reconstruction for Signet-Ring Cell Carcinoma with Skin Invasion Derived from the Anal Gland].

A 56-year-old man was referred to our hospital with an awareness of anal tumor. The tumor extended from the anal verge to the back of left testicle. Colonoscopy showed no tumor in the rectum and the anal canal. Biopsy showed mucus- producing adenocarcinoma(sig), and we diagnosed anal canal adenocarcinoma with immunostaining. Laparoscopic abdominoperineal rectal resection and perineal reconstruction with the V-Y fasciocutaneous flap closure technique. The patient had no major postoperative complications, and was discharged on 23rd postoperative day. Pathological examination revealed that the tumor was pT3N0M0, pStage ⅡB. The patient received adjuvant chemotherapy with CAPOX and has survived 12 months without recurrence. Immunostaining may be used to diagnose the signet-ring cell carcinoma without tumor of anal canal. In addition, reconstruction of the perineum for large anal tumors is useful.

[A Case of Robot-Assisted Abdominoperineal Resection with Prostatectomy for Locally Advanced Rectal Cancer].

The patient was referred to our hospital because of bloody stool and anorectal pain, and a colonoscopy revealed a tumor in the lower rectum. Although no distant metastasis was found, the tumor was suspected to have invaded the distal prostate. Neoadjuvant chemoradiotherapy(45 Gy/25 Fr with S-1)resulted in tumor shrinkage and symptomatic improvement, however, the primary tumor remained in close proximity to the prostate and urethra. Thus, we performed a robot-assisted abdominoperineal resection and Retzius-sparing prostatectomy in collaboration with the urology department. The surgical margins were negative and radical resection was achieved. Although minor vesicourethral anastomotic leakage was observed, it recovered conservatively. The patient has been alive 1 year postoperatively without recurrence. The patient initially had urinary incontinence, but it gradually improved. Although a total pelvic resection could have been considered, the robot-assisted surgery made it possible to preserve the urinary tract. The future application of robot-assisted surgery in extended surgery is expected.

Alternative microexon splicing by RBFOX2 and PTBP1 is associated with metastasis in colorectal cancer.

The splicing of microexons (very small exons) is frequently dysregulated in the brain of individuals with autism spectrum disorder. However, little is known of the patterns, regulatory mechanisms and roles of microexon splicing in cancer. We here examined the transcriptome-wide profile of microexon splicing in matched colorectal cancer (CRC) and normal tissue specimens. Out of 1492 microexons comprising 3 to 15 nucleotides, 21 (1%) manifested differential splicing between CRC and normal tissue. The 21 genes harboring the differentially spliced microexons were enriched in gene ontology terms related to cell adhesion and migration. RNA interference-mediated knockdown experiments identified two splicing factors, RBFOX2 and PTBP1, as regulators of microexon splicing in CRC cells. RBFOX2 and PTBP1 were found to directly bind to microexon-containing pre-mRNAs and to control their splicing in such cells. Differential microexon splicing was shown to be due, at least in part, to altered expression of RBFOX2 and PTBP1 in CRC tissue compared to matched normal tissue. Finally, we found that changes in the pattern of microexon splicing were associated with CRC metastasis. Our data thus suggest that altered expression of RBFOX2 and PTBP1 might influence CRC metastasis through the regulation of microexon splicing.

Wnt5a in cancer-associated fibroblasts promotes colorectal cancer progression.

Cancer-associated fibroblasts (CAFs) are a major component of the tumor microenvironment and have been shown to promote cancer aggressiveness. In our previous study, analysis of expression profiles obtained from paired CAFs and normal fibroblasts from colorectal cancer (CRC) tissue revealed that gene sets related to the Wnt signaling pathway were highly enriched in colorectal CAFs. Furthermore, among the components of the ß-catenin-independent Wnt pathway, Wnt5a was highly expressed in CAFs. Since Wnt5a is considered to be a regulator of CRC progression in CAFs, we performed immunohistochemical analysis on Wnt5a in 171 patients who underwent surgery for CRC. Positive staining for Wnt5a was often found in cancer stroma, particularly in fibromatous areas, although the immunoreactivity for Wnt5a was weak in cancer cells. Wnt5a status in CAFs was significantly associated with tumor size, depth of invasion, lymphatic and vascular invasion, lymph node metastasis, TNM stage, and recurrence. Subsequent in vitro analyses using human recombinant Wnt5a protein revealed that cancer cell proliferation and migration were significantly increased by stimulation with Wnt5a. Our findings suggest that Wnt5a-derived CAFs play a crucial role in CRC progression and have potential as a target of anti-cancer therapies.

The association between ERK inhibitor sensitivity and molecular characteristics in colorectal cancer.

The mitogen-activated protein kinase (MAPK) pathway plays an important role in the colorectal cancer (CRC) progression, being supposed to be activated by the gene mutations, such as BRAF or KRAS. Although the inhibitors of extracellular signal-regulated kinase (ERK) have demonstrated efficacy in the cells with the BRAF or KRAS mutations, a clinical response is not always associated with the molecular signature. The patient-derived organoids (PDO) have emerged as a powerful in vitro model system to study cancer, and it has been widely applied for the drug screening. The present study aims to analyze the association between the molecular characteristics which analyzed by next-generation sequencing (NGS) and sensitivity to the ERK inhibitor (i.e., SCH772984) in PDO derived from CRC specimens. A drug sensitivity test for the SCH772984 was conducted using 14 CRC cell lines, and the results demonstrated that the sensitivity was in agreement with the BRAF mutation, but was not completely consistent with the KRAS status. In the drug sensitivity test for PDO, 6 out of 7 cases with either BRAF or KRAS mutations showed sensitivity to the SCH772984, while 5 out of 6 cases of both BRAF and KRAS wild-types were resistant. The results of this study suggested that the molecular status of the clinical specimens are likely to represent the sensitivity in the PDOs but is not necessarily absolutely overlapping. PDO might be able to complement the limitations of the gene panel and have the potential to provide a novel precision medicine.

Resection rate curves by location along the small intestine provide perspectives on characteristics of Crohn's disease.

AIM: Crohn's disease (CD) can affect any part of the gastrointestinal tract; however, the frequency of CD lesions differs by location. This work aimed to examine resection rates by location to clarify locational characteristics of the small intestine in surgical CD cases. METHOD: This was a single-centre retrospective case note review of patients who had undergone resection for CD affecting the small intestine between January 2014 and February 2020. Operative details, including length of the small intestine, location and extent of the resection, identified the pattern of disease. By normalizing these data the resection rate along the length of the intestine was calculated to create resection rate curves. RESULTS: One hundred and twenty six surgical cases were identified. The resection rate curves could be divided into two types: exponential and bimodal. For primary surgery, this depended on whether or not surgery was limited to an ileocolic resection. At subsequent surgery, a previous ileocaecal resection influenced the pattern of disease. The peaks of the bimodal curve were located at the proximal and distal ileum. CONCLUSION: CD patients requiring resection of the small intestine can be divided into terminal ileum type (exponential type) and proximal ileum type (bimodal type). In the future this analytical method may help predict the site of any recurrent disease but also provides a new perspective on the disease.

Comprehensive Analysis of microRNA Profiles in Organoids Derived from Human Colorectal Adenoma and Cancer.

INTRODUCTION: Exosomes are membrane-enclosed nanovesicles, which are increasingly being recognized as important cell communication components for their role in transmitting microRNAs (miRNAs). No previous study has addressed the exosomal miRNA profile in colorectal adenomas (CRAs) because the long-term culture of CRA is challenging. This study aimed to identify the miRNA signature in organoid exosomes derived from human CRA and colorectal cancer (CRC) samples. METHODS: Organoid cultures were developed from resected colorectal tissues of patients with CRA or CRC undergoing surgery or endoscopic mucosal resection. Exosomes were prepared from the conditioned medium of the organoids. miRNAs were prepared from the exosomes and their source organoids. The miRNA expression profiles were compared using microarray analysis. The impact of alteration of miRNA expression on cell proliferation was examined using miRNA mimics or inhibitors in HT-29 human CRC cells. RESULTS: We established 6 organoid lines from CRC and 8 organoid lines from CRA. Exosomal miRNA signatures were different between the organoids derived from CRA and CRC. Both exosomal and cellular miR-1246 expressions were upregulated in CRC-derived organoids compared to their expression in CRA-derived organoids. Alteration of miR-1246 expression by the miR-1246 mimic or inhibitor increased or decreased cell proliferation in HT-29 cells, respectively. CONCLUSIONS: We report for the first time the miRNA profiles of exosomes in CRA- and CRC-derived organoids. The upregulation of miR-1246 might play a role in increased cell proliferation in the process of CRA-carcinoma transition.

A Phenylfurocoumarin Derivative Reverses ABCG2-Mediated Multidrug Resistance In Vitro and In Vivo.

The ATP-binding cassette subfamily G member 2 (ABCG2) transporter is involved in the development of multidrug resistance in cancer patients. Many inhibitors of ABCG2 have been reported to enhance the chemosensitivity of cancer cells. However, none of these inhibitors are being used clinically. The aim of this study was to identify novel ABCG2 inhibitors by high-throughput screening of a chemical library. Among the 5812 compounds in the library, 23 compounds were selected in the first screening, using a fluorescent plate reader-based pheophorbide a (PhA) efflux assay. Thereafter, to validate these compounds, a flow cytometry-based PhA efflux assay was performed and 16 compounds were identified as potential inhibitors. A cytotoxic assay was then performed to assess the effect these 16 compounds had on ABCG2-mediated chemosensitivity. We found that the phenylfurocoumarin derivative (R)-9-(3,4-dimethoxyphenyl)-4-((3,3-dimethyloxiran-2-yl)methoxy)-7H-furo [3,2-g]chromen-7-one (PFC) significantly decreased the IC50 of SN-38 in HCT-116/BCRP colon cancer cells. In addition, PFC stimulated ABCG2-mediated ATP hydrolysis, suggesting that this compound interacts with the substrate-binding site of ABCG2. Furthermore, PFC reversed the resistance to irinotecan without causing toxicity in the ABCG2-overexpressing HCT-116/BCRP cell xenograft mouse model. In conclusion, PFC is a novel inhibitor of ABCG2 and has promise as a therapeutic to overcome ABCG2-mediated MDR, to improve the efficiency of cancer chemotherapy.

[A Case of Rectal Cancer with Disseminated Intravascular Coagulation Successfully Treated with Emergent Chemotherapy].

A 70's woman complaining blood stool and lower abdominal pain visited a local doctor and was given the diagnosis of rectal cancer by colonoscopy. CT, MRI, and bone scintigraphy revealed multiple lymph node and bone metastasis and peritoneal dissemination. She had developed disseminated intravascular coagulation(DIC)during hospitalization, and the cause was considered to be disseminated carcinomatosis of the bone marrow. Thus, we emergently started chemotherapy with mFOLFOX6, in conjunction with anticoagulation therapy, and the DIC was resolved 11 days after the introduction. Partial response was achieved and the chemotherapy has been continued after 5 months from the onset of the DIC. Since the prognosis of solid tumor patients who developed DIC has been reported to be extremely poor, prompt introduction of chemotherapy should be considered.

[A Case of Curative Resection after Neoadjuvant Chemotherapy for Locally-Advanced Sigmoid Colon Carcinoma with Urinary Bladder Invasion].

A 56-year-old man was referred to our hospital for multidisciplinary treatment of advanced sigmoid colon carcinoma with a suspected bladder invasion. The patient received 8 courses of modified Leucovorin, fluorouracil, and oxaliplatin (mFOLFOX6)plus panitumumab as neoadjuvant chemotherapy for reliable and safe radical resection after ileostomy construction. There was a significant reduction in the tumor size following chemotherapy; hence, low anterior resection was performed. In addition, since preoperative and intraoperative findings suggested bladder invasion, a total cystectomy with ileal conduit urinary diversion was performed. The pathological diagnosis was ypT4b, N0, M0, and ypStage Ⅱc, with all surgical margins being negative. Subsequently, the patient received adjuvant chemotherapy with 4 courses of mFOLFOX6, and his condition improved with no incidence of cancer recurrence following 8 months after the operation. Neoadjuvant chemotherapy for locally advanced colon cancer is one of the effective treatments for reliable and safe radical resection.

The Function and Prognostic Significance of Cripto-1 in Colorectal Cancer.

Cripto-1 is a plasma membrane protein which is not expressed in adult tissue, but some tumors are accompanied by re-activation. We studied the clinical and biological significance of Cripto-1 in colorectal cancer. Cripto-1 was positive in 68 out of 192 cases (35%) by immunohistochemistry. Cripto-1 expression was correlated with worse prognosis and was an independent prognostic factor. Cripto-1-silenced colorectal cancer cell lines had reduced cell proliferation, migration, and activation of Akt and MAPK signaling pathways in vitro, and decreased tumor growth and lymph node metastasis in vivo. Cripto-1 could be a useful prognostic biomarker and therapeutic target in colorectal cancer.

[A Case of Sigmoid Colon Cancer with Thrombotic Microangiopathy].

A 50's man was referred to our hospital because of sigmoid colon cancer with multiple liver metastases and para-aortic lymph node metastases. Although blood test showed elevated D-dimer(50 µg/mL), there was no significant thrombus in contrast-enhanced CT scan. Since cancer pain and symptoms of bowel obstruction had continued after endoscopic stent placement, we resected primary lesion. Despite anemia and elevated D-dimer level had persisted after the operation, there were no obvious bleeding source nor thrombus. Continuous intravenous heparin infusion was started for hypercoagulability. Then, D-dimer and CRP levels were promptly decreased. Since schizocyte and giant platelets were observed in peripheral blood smear, he was eventually diagnosed with thrombotic microangiopathy as a paraneoplastic syndrome. However D- dimer and CRP levels were re-elevated, and it seemed to be necessary to control cancer progression. Thus, cetuximab monotherapy was started considering his performance status. After starting cetuximab, fever and CRP level were immediately improved. Cetuximab appeared to be very effective, but he died of acute subdural hematoma. Continuous intravenous heparin infusion was supposed to be effective in the treatment of thrombotic microangiopathy along with the management of cancer.

[A Case of Radically Resected Sigmoid Colon Cancer with Bladder Invasion after Chemotherapy and Weight Loss in an Extremely Obese Patient].

A 30's extremely obese patient(body mass index: BMI 45 kg/m2)was referred to our hospital with a chief complaint of bloody urine and stool. Colonoscopy revealed a sigmoid colon tumor. Barium enema examination revealed stenosis of the sigmoid colon. CT scan showed a tumor in the sigmoid colon, with bladder invasion. The para-aortic lymph node was partially swollen. We considered surgery to be high risk because of the patient's severe obesity. Therefore, we decided to examine the possibility of radical surgery followed by chemotherapy(mFOLFOX6/cetuximab)with weight reduction. Following this, the tumor had shrunk remarkably, and the patient's BMI decreased from 45 kg/m2 to 39 kg/m2. The visceral fat area was reduced from 298 cm2 to 199 cm2 at the umbilical level. We then performed a sigmoid colectomy with partial resection of the bladder. Thus, chemotherapy combined with weight loss enabled us to perform radical surgery safely for a locally advanced sigmoid colon cancer in a patient with severe obesity.

[Bladder-Sparing Surgery with Preoperative Chemotherapy for Rectal Cancer with Urinary Bladder Involvement-A Case Report].

A 65-year-old male was diagnosed with rectal cancer invading the urinary bladder, swollen para-aorticlymph nodes, and multiple liver metastases in abdominal CT. After 8 courses of mFOLFOX6 plus panitumumab, the rectal cancer, para-aortic lymph nodes metastasis, and liver metastases decreased significantly in size. Rectal cancer and liver metastases were considered resectable, hence low anterior resection of the rectum was performed. Intraoperative frozen section analysis showed negative metastaticinvolvement of the para-aorticlymph nodes and surgical margins of the urinary bladder; therefore, the urinary bladder was completely preserved. Partial resection of the liver was performed 2 months later. In conclusion, the patient showed good surgical and quality of life results. Thus, the bladder-sparing strategy with preoperative chemotherapy could be considered for appropriately selected rectal cancer patients with urinary bladder involvement.

Novel biomarkers distinguishing pancreatic head Cancer from distal cholangiocarcinoma based on proteomic analysis.

BACKGROUND: The differentiation between pancreatic head cancer (PHC) and distal cholangiocarcinoma (DCC) can be challenging because of their anatomical and histopathological similarity. This is an important problem, because the distinction has important implications for the treatment of these malignancies. However, there are no biomarkers for the differential diagnosis of PHC and DCC. The present study aimed to identify novel diagnostic immunohistochemical biomarkers to distinguish PHC from DCC. METHODS: Liquid chromatography tandem mass spectrometry (LC-MS/MS) was employed to detect candidate proteins. Ten PHC and 8 DCC specimens were analyzed by LC-MS/MS. Selected proteins were evaluated, using immunohistochemical analysis, to determine whether they would be appropriate biomarkers. Finally, we generated biomarker panels to improve diagnostic accuracy. We applied these panels to clinically difficult cases (cases in which different diagnoses were made before and after operation). RESULTS: Consequently, 1820 proteins were detected using LC-MS/MS. Fifteen differentially expressed proteins were selected as candidates based on semi-quantitative comparison. We first performed immunohistochemical staining on samples from the small cohort group (12 PHCs and 12 DCCs) using 15 candidates. KRT17, ANXA10, TMEM109, PTMS, and ATP1B1 showed favorable performances and were tested in the next large cohort group (72 PHCs and 74 DCCs). Based on immunohistochemical analysis, KRT17 performed best for the diagnosis of PHC as a single marker; additionally, PTMS exhibited good performance for the diagnosis of DCCs. Moreover, we indicated the KRT17+/ANXA10+/PTMS- staining pattern as a biomarker panel for the correct diagnosis of PHC and KRT17-/ANXA10-/PTMS+ for the diagnosis of DCC. After immunohistochemical staining for examining samples from the clinically difficult cases, these panels showed satisfactory diagnostic performance with 85.7% (6/7) accuracy. CONCLUSIONS: We conclude that 5 proteins and 2 biomarker panels are promising for distinguishing PHC from DCC, and patients with an equivocal diagnosis would benefit from the application of these biomarkers. Confirmatory studies are needed to generalize these findings to other populations.

Combination of longitudinal pancreaticojejunostomy with coring-out of the pancreatic head (Frey procedure) and distal pancreatectomy for chronic pancreatitis.

PURPOSE: The Frey procedure is an effective surgery for chronic pancreatitis (CP) patients who have pancreatic head lesions with dilation of the main pancreatic duct. However, pancreatic tail lesions can cause relapsing pancreatitis after the procedure. Therefore, additional distal pancreatectomy (DP) might complement the therapeutic effect of the Frey procedure in controlling inflammation of the pancreatic tail. The Frey procedure with DP (Frey + DP) is indicated for inflammatory lesions in the pancreatic head and tail. In this study, we assessed the usefulness of Frey + DP using the retrospective clinical data of our cases. METHODS: The clinical outcomes were compared between CP patients who underwent the Frey procedure (N = 44) and Frey + DP (N = 13) from January 2005 to April 2016. RESULTS: Frey + DP showed similarly good therapeutic effects to the Frey procedure with regard to the postoperative stay, morbidity, mortality, pain relief and nutrition, although the Frey + DP had a longer operative time, more bleeding and higher incidence of diabetes mellitus than the Frey procedure because of the additional DP. One patient in the Frey group received additional DP because of recurrent pain due to the tail lesion. CONCLUSION: Frey + DP can be a promising treatment for CP patients with pancreatic head and tail lesions.

[A Case of Solitary Residual Lateral Pelvic Lymph Node Metastasis Despite Complete Response of Primary Rectal Cancer Followed by Neoadjuvant Chemoradiotherapy].

A 45-year-old woman was referred to our hospital complaining of diarrhea. Colonoscopy showed a rectal tumor. Histological examination showed moderately differentiated adenocarcinoma. A CT scan revealed a tumor extending from the lower rectum to the anal canal with a lateral pelvic lymph node(LPLN)swelling. We administered neoadjuvant chemoradiotherapy (45 Gy/25 Fr, S-1 80mg/m / 2/day)and the tumor and LPLN shrank remarkably, with a clinically complete response by CT and PET-CT. We then performed abdominoperineal resection with D3 lymph node and bilateral LPLN dissection. Pathological examination revealed complete disappearance of the cancer cells in the primary site, while lymph node metastasis was detected in one LPLN. We report here a rare case in which LPLN metastasis remained despite the pathological complete response of the primary tumor.

[A Case of Curatively Resected Locally Recurrent Rectal Mucinous Adenocarcinoma Followed by Preoperative Chemoradiotherapy].

A 60s man was diagnosed with rectal cancer and underwent low anterior resection of the rectum. The pathological diagnosis was mucinous adenocarcinoma, pT3(SS), pN0, pM0, pStage Ⅱ. Two years after the primary surgery, contrast-enhanced CT showed local recurrence on the oral side of the anastomosis. As the tumor had invaded the left seminal vesicle and coccygeus muscle, neoadjuvant chemoradiotherapy(NACRT)(S-1 80mg/m / 2 plus 45 Gy/25 Fr)was performed. After NACRT, abdominoperineal resection, including the left seminal vesicle, coccygeus muscle, and coccygeal bone, was performed. Pathological examination showed a histological response of Grade 2 and that R0 resection was achieved. Although the only radical treatment of locally recurrent rectal cancer is R0 resection, we performed R0 resection with Grade 2 histological response to NACRT.