Search

Abstract Background Portal hypertensive enteropathy (PHE) is a small-bowel lesion observed in patients with portal hypertension. The clinical significance of endoscopic findings in PHE remains unclear. We aimed to clarify the clinical significance and predictive factors of capsule endoscopic findings in patients with PHE based on long-term outcomes. Methods This retrospective study enrolled 55 patients with PHE (33 males and 22 females; median age, 64 years; range, 23–87) followed for > 3 years using capsule endoscopy (CE) between February 2009 and May 2023. We evaluated the clinical factors affecting PHE exacerbations and the effects of PHE exacerbations on gastrointestinal bleeding by comparing exacerbated and unchanged PHE groups. Results Overall, 3 (5%) patients showed improvement, 33 (60%) remained unchanged, and 19 (35%) showed exacerbation on follow-up CE. In the exacerbated group, the rates of worsened fibrosis-4 index, exacerbated esophageal varices, and exacerbated portal hypertensive gastropathy were significantly higher than those in the unchanged group (21%, 32%, and 42% vs. 3%, 6%, and 12%, respectively; P

BackgroundAdditional surgery with lymph node (LN) dissection is recommended for pT1 colorectal carcinoma (CRC) resected by endoscopy, based on pathological risk factors for LN metastasis (LNM), according to guidelines by the Japanese Society for Cancer of the Colon and Rectum (JSCCR), National Comprehensive Cancer Network (NCCN), and European Society for Medical Oncology (ESMO).MethodsWe retrospectively analyzed 560 consecutive patients with T1 CRC who underwent endoscopic resection alone (n=190) or initial or additional surgery with LN dissection (n=370) between 1992 and 2017 at Hiroshima University Hospital. Patients were classified into LNM low- and high-risk groups according to guidelines by the JSCCR, NCCN, and ESMO as follows. Patients without any specified pathological LNM risk factor were included in the LNM low-risk group, while the high-risk group comprised all other patients. We analyzed the LNM predictive ability of each guideline.ResultsThe LNM high-risk rate, sensitivity, specificity, positive and negative predictive values, accuracy of LNM risk, and AUC for LNM predictive ability were 82%, 100%, 19%, 9%, 100%, 26% and 0.596 in the JSCCR guidelines; 52%, 98%, 52%, 15%, 99%, 56%, and 0.749 in the NCCN; and 54%, 98%, 50%, 15%, 99%, 54%, and 0.743 in the ESMO, respectively.ConclusionsThe JSCCR guidelines could diagnose LNM in all cases but had the highest false-positive rate. It is important to reduce unnecessary additional surgeries for pT1 CRCs after ER.

Abstract Background The validity of endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) in older individuals with comorbidities remains unclear. Therefore, this study evaluated the safety and efficacy of ESD and additional treatment for ESCC in older adult patients. Methods The clinicopathological characteristics and clinical outcomes of 398 consecutive older adult patients (≥ 65 years) with 505 lesions who underwent ESD for ESCC at the Hiroshima University Hospital between September 2007 and December 2019 were retrospectively evaluated. Additionally, the prognoses of 381 patients who were followed up for > 3 years were assessed. Results The mean patient age and procedure time were 73.1 ± 5.8 years and 77.1 ± 43.5 min, respectively. The histological en bloc resection rate was 98% (496/505). Postoperative stenosis, perforation, pneumonia, and delayed bleeding were conservatively treated in 82 (16%), 19 (4%), 15 (3%), and 5 (1%) patients, respectively. The 5-year overall and disease-specific survival rates were 78.9% and 98.0%, respectively (mean follow-up time: 71.1 ± 37.3 months). Multivariate analysis showed that age and the American Society of Anesthesiologists classification of physical status class ≥III (hazard ratio: 1.27; 95% confidence interval: 1.01–1.59, p = 0.0392) were independently associated with overall survival. A significantly lower overall survival rate was observed in the high-risk follow-up group than in the low-risk follow-up and high-risk additional treatment groups (p

Abstract Background/Aims Chronic constipation (CC) is one of the most common gastrointestinal disorders in the general population. Although there are many treatment options, achieving a stable treatment for CC remains one of the challenges in clinical practice. This study aimed to evaluate the clinical factors associated with stable treatment for CC in Japanese patients. Methods A retrospective, cross-sectional, and multicenter study was carried out. Patients were eligible for inclusion if they fulfilled the Rome IV criteria for diagnosing CC and had been treated for at least one and a half years. Patients with up to two prescription modifications for CC in one year were defined as the stable treatment group, whereas those with three or more prescription changes were defined as the unstable treatment group. Univariate and multivariate analyses were carried out to identify factors associated with CC. Results A total of 114 patients have been recruited. There were 82 patients (77.0%) in the stable treatment group and 32 patients (23.0%) in the unstable treatment group. Based on multivariate likelihood analysis, only using acid-suppressive drugs contributed to stability treatment in CC patients (odds ratio: 2.81, 95% confidence interval: 1.12–7.08, p = 0.03). Conclusion Administration of acid-suppressive drugs was the only factor related to the stability of CC treatment. Further studies are needed to validate the results as well as clarify the causes.

Abstract Background Methods to prevent esophageal stenosis (ES) after endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell carcinoma (ESCC) have received increasing attention. Although steroid administration is a prophylactic treatment, the risk factors for ES during prophylactic steroid therapy remain unknown. Therefore, this study aimed to retrospectively evaluate the risk factors for refractory ES in patients administered prophylactic steroids after ESD for ESCC. Methods Among 795 patients with ESCC (854 lesions), 180 patients (211 lesions) administered local triamcinolone acetonide (TrA) and/or oral prednisolone were recruited for this study. We compared the total number of endoscopic balloon dilatation (EBD) procedures performed for post-ESD ES and clinical findings (tumor size, ESD history or chemoradiation therapy [CRT], entire circumferential resection, muscle layer damage, supplemental oral prednisolone administration, EBD with TrA injection, and additional CRT) between patients with refractory and non-refractory ES. EBD was continued until dysphagia resolved. We categorized cases requiring ≥ 8 EBD procedures as refractory postoperative stenosis and divided the lesions into two groups. Results Multivariate logistic regression analysis revealed that factors such as ESD history, CRT history, tumor size, and entire circumferential resection were independently associated with the development of refractory ES. The withdrawal rates of EBD at 3 years were 96.1% (52/53) and 58.5% (39/59) in the non-refractory and refractory groups, respectively. Conclusions Our data suggest that entire circumferential resection and CRT history are risk factors for refractory post-ESD ES in ESCC, even with prophylactic steroid administration.

Abstract Objectives Underwater endoscopic mucosal resection (UEMR) is a simpler procedure for superficial non‐ampullary duodenal epithelial tumors (SNADET) than conventional endoscopic mucosal resection (cEMR). This study aimed to evaluate whether cEMR can be substituted by UEMR for SNADET in terms of effectiveness, safety, and learning curve. Methods A total of 157 consecutive patients with 203 SNADETs ≤20 mm in diameter, including 107 lesions resected by cEMR and 96 lesions resected by UEMR, between January 2019 and May 2023, were retrospectively recruited. The treatment outcomes were compared between the cEMR and UEMR groups. The risk factors for incomplete resection by UEMR were analyzed using univariate and multivariate analyses. Lesions in the UEMR group were divided chronologically into five periods; thereafter, the en bloc resection rate and procedure time were compared. Results No significant differences existed between the cEMR and UEMR groups in the mean procedure time (3.9 min vs. 3.6 min, p = 0.1380) or en bloc resection rate (91% vs. 94%, p = 0.4138). No perforation was observed in either group. Tumor size was an independent risk factor for incomplete resection using UEMR (p

Tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) are known to play supportive roles in tumor development and progression, but their interactions in colorectal cancer (CRC) remain unclear. Here, we investigated the effects of colon-cancer-derived CAFs on TAM differentiation, migration, and tumor immunity, both in vitro and in vivo. When co-cultured with monocytes, CAFs attracted monocytes and induced their differentiation into M2 macrophages. Immunohistology of surgically resected human CRC specimens and orthotopically transplanted mouse tumors revealed a correlation between numbers of CAFs and numbers of M2 macrophages. In a mouse model of CRC orthotopic transplantation, treatment with an inhibitor of the colony-stimulating factor-1 receptor (PLX3397) depleted M2 macrophages and increased CD8-positive T cells infiltrating the tumor nest. While this treatment had a minor effect on tumor growth, combining PLX3397 with anti-PD-1 antibody significantly reduced tumor growth. RNA-seq following combination therapy showed activation of tumor immunity. In summary, CAFs are involved in the induction and mobilization of M2 macrophage differentiation in the CRC tumor immune microenvironment, and the combination of cancer immunotherapy and PLX3397 may represent a novel therapeutic option for CRC.

Abstract Background Esophageal squamous cell carcinoma (ESCC) is sometimes detected in non‐drinker and non‐smoker females who are considered to have very low risk of ESCC development in daily practice. This study examined the clinicopathological and genomic characteristics of ESCCs in females with no history of drinking and smoking. Methods The sample comprised 118 ESCC lesions occurring in 95 female patients who underwent endoscopic submucosal dissection at our department between January 2008 and December 2019. The patients were categorized into two groups: 51 lesions in 49 patients with no history of drinking and smoking (nondrinker/nonsmoker [NDNS] group) and 69 lesions in 45 patients with a history of drinking or smoking (drinker/smoker [DS] group). We analyzed the differences in clinicopathological and cancerous genomic characteristics between the groups. Significant genomic alterations were validated using immunohistochemistry. Results Multiple logistic regression revealed that older age, fewer multiple Lugol‐voiding lesions (LVLs), and reflux esophagitis (RE) were independently associated with the occurrence of ESCCs in the NDNS group. ESCC lesions in the NDNS group were predominantly located in the mid‐thoracic esophagus, posterior wall side, with 0‐IIa, the aspect ratio of the lesion >2 (vertical/horizontal), and endoscopic keratinization. Genetic analysis showed that CDKN2A driver alterations were significantly more frequent and KMT2D alterations were significantly less frequent in the NDNS group than in the DS group. KMT2D alterations were strongly correlated with immunostaining. Conclusion Older nondrinker, nonsmoker females with RE and fewer multiple LVLs may develop longitudinal 0‐IIa ESCC with keratinization of the posterior wall of the mid‐thoracic esophagus. ESCCs in nondrinker, nonsmoker females had fewer KMT2D alterations and more CDKN2A alterations, which may be a biomarker for treatment.

Abstract Background The ABC method, which combines the pepsinogen method and anti-Helicobacter pylori antibody titers, has been used for risk screening for gastric cancer in Japan. However, it has been reported that there are cases of gastritis and carcinogenesis risk even in group A, which is considered to be a low-risk group based on the ABC method. Currently, in group A, endoscopic examination is needed to strictly discriminate “patients without gastritis” (defined as true A patients) from those “with gastritis.” A simple and minimally invasive diagnostic criterion for gastritis using serological markers is desirable. In this study, we aimed to identify the normal serum gastrin concentrations in normal stomach cases based on pathological diagnosis and investigate the usefulness of serum gastrin concentrations in diagnosing gastritis. Methods Patients who underwent endoscopy and blood tests at Hiroshima University Hospital were enrolled in the study and categorized into the “pathologically-evaluated group” and “endoscopically-evaluated group,” according to the evaluation method of atrophic gastritis. Initially, we measured serum gastrin concentrations in the normal stomach cases in the pathologically-evaluated group and calculated the normal range of serum gastrin concentrations. We used the upper limit of this normal range of serum gastrin concentrations and performed a validation study to determine its usefulness as a diagnostic marker for distinguishing between cases of gastritis and true A in the endoscopically-evaluated group. Results The 95th percentile of serum gastrin concentrations in pathologically-evaluated normal stomach cases was 34.12–126.03 pg/mL. Using the upper limit of this normal range of serum gastrin concentrations, the sensitivity, specificity, positive predictive value, and negative predictive value for gastritis were 52.8%, 92.6%, 97.0%, and 31.0%, respectively. Additionally, the receiver operating characteristic (ROC) curve for the endoscopically-evaluated group showed an area under the ROC curve of 0.80. Conclusion The gastrin cut-off value of 126 pg/mL has a good positive predictive value (97.0%) for detecting gastritis positing its use as a marker for cases requiring endoscopy. However, the identification of patients with gastritis having normal serum gastrin concentrations due to insufficient sensitivity remains a challenge for the future.

Abstract Background Gastric cancer remains a severe public health problem worldwide, particularly in Japan. Recent studies have demonstrated that serum markers are beneficial for risk stratification in gastric cancer development. We aimed to evaluate the usefulness of serum markers either alone or in combination (serum markers plus endoscopy) for effective risk stratification of gastric cancer development. Methods We enrolled 22,736 patients aged 20–95 years who underwent blood sampling and endoscopic examination at Hiroshima University Hospital in Japan between 1990 and 2014. The serum pepsinogen (PG) levels and anti-Helicobacter pylori antibody (Hp-Ab) titers were evaluated in each patient. The enrolled patients were matched with the database of the Hiroshima Prefecture Regional Cancer Registry. We processed the medical records and excluded patients with possible confounding factors for PG levels, such as proton pump inhibitor use, prior successful eradication therapy, post-gastrectomy, severe hepatorenal dysfunction, Zollinger–Ellison syndrome, and autoimmune gastritis. Among the remaining 5131 patients, we reviewed records of endoscopic examinations and selected 1507 patients (mean age, 62.5 years; 985 men and 522 women) who underwent endoscopic examination more than three months after blood sampling. First, based on the ABC method, patients were classified as follows: High PG levels and negative Hp-Ab, group A, high PG levels and positive Hp-Ab, group B, low PG levels and positive Hp-Ab, group C, and low PG levels and negative Hp-Ab, group D. Group A was further classified into two subgroups using endoscopic findings: true A without atrophic gastritis and pseudo A with atrophic gastritis. All patients underwent annual endoscopy follow-up. Results Among the 1,507 patients (mean age, 62.5 years; 985 men), 24 were diagnosed with newly developed gastric cancer. No significant difference in cancer development was found between group A (PG negative and Hp-Ab negative) and the other groups. Remarkably, no true A group subjects developed gastric cancer. Conclusions The combination of serum markers and endoscopic findings is essential for the risk evaluation of gastric cancer.

Background and study aims Prevention of bleeding and perforation during gastric endoscopic submucosal dissection (ESD) is important. Scissor-type knives can accurately grasp and incise the targeted tissue using electrosurgical currents, thereby eliminating unexpected incisions. The SB Knife GX, a scissor-type knife specialized for gastric ESD, was released in June 2016 in Japan. The aim of the present study was to evaluate the efficacy and safety of gastric ESD using the SB Knife GX. Patients and methods A total of 716 patients who underwent gastric ESD at Hiroshima University Hospital between July 2016 and December 2020 were retrospectively reviewed. From these, 671 patients underwent ESD using the IT Knife 2 (IT-2 group), while 45 underwent ESD using an SB Knife GX (SB-GX group). After propensity score matching, the procedure time, specimen size, en bloc and complete resection rates, and intraoperative bleeding, delayed bleeding, and perforation rates were evaluated. Results No significant differences were observed in mean procedure time (SB-GX group: 115 ± 165 min; IT-2 group: 95 ± 61 min; P = 0.82) and en bloc and complete resection rates between the two groups. Intraoperative bleeding rates were significantly lower in the SB-GX group than in the IT-2 group (18 % vs. 40 %; P = 0.01), and there were no differences in delayed bleeding (4 % vs. 4 %) or perforation (0 % vs. 4 %) between the two groups. Conclusions The SB Knife GX was proven to be useful for control of intraoperative bleeding during gastric ESD, although the procedure time tended to be longer.

The risk of malignant tumor progression has been a concern associated with the use of anti-tumor necrosis factor-alpha monoclonal antibody (anti-TNFα mAb). On the contrary, recent observational studies have reported negatively on this risk and instead suggested that anti-TNFα mAb acts as a tumor suppressor in inflammatory carcinogenesis models and subcutaneous transplant models of colorectal cancer. However, no consensus has been established regarding the actual effects of anti-TNFα mAb on malignant tumors. Here, we aimed to evaluate, for the first time, the effect of anti-TNFα mAb on the tumor microenvironment in the absence of intestinal inflammation in a colorectal cancer orthotopic transplant mouse model suitable for tumor microenvironment assessment. The orthotopic transplantation model was developed by transplanting CT26 cells into the cecum of BALB/c mice. Changes in tumor size and weight were recorded 3 weeks after transplantation, and the tumor microenvironment was assessed via RNA sequencing and immunohistological staining. In the orthotopic transplant model, the administration of anti-TNFα mAb led to a reduction in colorectal cancer. The RNA sequencing analysis showed upregulation of immune-related pathways and apoptosis and suppression of stromal- and tumor growth-related pathways. Additionally, Gene Ontology analysis showed inhibition of angiogenesis. Immunohistochemical staining showed inhibition of tumor growth, increase in apoptosis, suppression of stromal response, suppression of angiogenesis, enhancement of tumor immunity, and reduction in the number of tumor-associated macrophages. Anti-TNFα mAb acts as an inhibitor of tumor progression in the tumor microenvironment of a colorectal cancer orthotopic transplant mouse model.

Abstract Background Many studies have revealed that mucosal healing improves the long-term prognosis of ulcerative colitis. Frequent colonoscopy is difficult because of its invasiveness and cost. Therefore, in diagnosing and treating ulcerative colitis, noninvasive, low-cost methods for predicting mucosal healing using useful biomarkers are required in the clinical setting. This study aimed to evaluate whether serum amyloid A is a better serum biomarker than C-reactive protein in predicting mucosal healing in ulcerative colitis patients in clinical remission. Methods Ulcerative colitis patients whose C-reactive protein and serum amyloid A were measured within 1 month before and after colonoscopy were included in this retrospective study, and the relationship between the C-reactive protein and serum amyloid A values and the mucosal condition was analyzed. Mucosal condition was assessed using the Mayo Endoscopic Score, with score 0 or 1 indicating mucosal healing. Results A total of 199 colonoscopic examinations were conducted in 108 ulcerative colitis patients who underwent C-reactive protein and serum amyloid A blood tests. In clinical remission patients, serum amyloid A showed a strong correlation with mucosal inflammation compared to C-reactive protein and had excellent sensitivity and specificity rates with significant statistical significance. Conclusions Serum amyloid A is a more useful marker compared to C-reactive protein in predicting mucosal inflammation in ulcerative colitis patients in clinical remission.

Acid secretion inhibitors, such as proton pump inhibitors (PPIs) and potassium competitive acid blockers (PCABs), are used to treat ulcers after endoscopic submucosal dissection (ESD) for early gastric cancer. These drugs can influence serum gastrin and pepsinogen (PG) levels; however, their definite effects remain unclear. This open-label, randomized study investigated the effect of acid secretion inhibitors on the serum gastrin and pepsinogen levels. In total, 76 patients were enrolled in the study. They underwent gastric ESD and received a PPI (n=21) or PCAB (n=55). Changes in the serum gastrin and PG levels before and 4 weeks after administration were examined. Patient factors associated with the alteration of serum PG or gastrin levels were identified. The median serum levels of gastrin, PGI, and PGII before the administration of the acid secretion inhibitors were 110.5 pg/mL, 36.4 ng/mL, and 8.9 ng/mL, respectively; after administration, the levels increased to 300 pg/mL, 64.7 ng/mL, and 15.8 ng/mL, respectively (P

Serum amyloid A (SAA) is an acute phase inflammatory protein that we previously described as a robust biomarker of colorectal inflammation in patients with ulcerative colitis (UC) in clinical remission. However, what induces SAA expression in UC remains unclear. This study demonstrates that SAA is significantly expressed in the intestinal tract of UC mouse models when compared with C-reactive protein, another inflammatory biomarker. Moreover, interleukin-6 and tumor necrosis factor-α were found to promote SAA1 expression, as were Toll-like receptor ligands flagellin and lipopolysaccharide. Furthermore, results suggested that the nuclear factor-kappa B (NF-κB) pathway may be involved in the promotion of SAA1 expression by flagellin, which was inhibited by treatment with 5-aminosalicylic acid (5-ASA). Therefore, the flagellin/NF-κB/SAA1 axis may represent one of the mechanisms by which 5-ASA suppresses intestinal inflammation.

Abstract Most patients with gastric mucosa‐associated lymphoid tissue (MALT) lymphoma are infected with Helicobacter pylori, and eradication therapy is the first‐line treatment for localized disease with H pylori infection. However, there were several reports showing effectiveness of eradication therapy in even H pylori negative cases. Gastric MALT lymphomas are endoscopically classified into three common types: superficial, ulcerative, and elevated types. For the past 20 years, we have encountered 200 cases of localized gastric MALT lymphoma. Among them, only 4 cases (2%) showed similar macroscopic findings to those of nodular gastritis (gastric MALT lymphoma with nodular gastritis‐like appearance; M‐NGA). Here, we compared clinicopathological characteristics and prevalence of non‐H pylori Helicobacter (NHPH) infection between M‐NGA and other common types of gastric MALT lymphoma. To examine the prevalence of NHPH infection, DNA was extracted from formalin‐fixed paraffin‐embedded biopsy tissues from four cases of M‐NGA, 20 cases of common endoscopic types of gastric MALT lymphoma, and 10 cases of nodular gastritis. We used a highly sensitive polymerase chain reaction assay to detect the presence of five species of NHPH (Helicobacter suis, H felis, H bizzozeronii, H salomonis, and H heilmannii). H suis infection was detected in 4, 2, and 0 of the 4, 20, and 10 cases of M‐NGA, other types of gastric MALT lymphoma, and nodular gastritis, respectively. Other NHPH species were not detected in any cases. Complete response rate by eradication therapy was 4/4 in M‐NGA cases. Therefore, nodular gastritis‐like MALT lymphoma, which shows a very rare phenotype, is closely associated with NHPH infection, and eradication therapy may be the first‐choice treatment.

Accumulating evidence suggests that a unique set of receptor tyrosine kinases, known as discoidin domain receptors (DDRs), plays a role in cancer progression by interacting with the surrounding collagen matrix. In this study, we investigated the expression and role of DDR1 in human gastric cancer metastasis. Proliferation, migration, invasion, and tube formation assays were conducted in DDR1-expressing MKN74 gastric cancer cells and corresponding DDR1-silenced cells. The effects of DDR1 on tumor growth and metastasis were examined in orthotopically implanted and experimental liver metastasis models in nude mice. The expression of DDR1 in surgical specimens was analyzed by immunohistochemistry. DDR1 was expressed in human gastric cancer cell lines, and its expression in human gastric tumors was associated with poor prognosis. Among seven gastric cancer cell lines, MKN74 expressed the highest levels of DDR1. DDR1-silenced MKN74 cells showed unaltered proliferation activity. In contrast, migration, invasion, and tube formation were significantly reduced. When examined in an orthotopic nude mouse model, DDR1-silenced implanted tumors significantly reduced angiogenesis and lymphangiogenesis, thereby leading to reductions in lymph node metastasis and liver metastasis. In a model of experimental liver metastasis, DDR1-silenced cells almost completely inhibited liver colonization and metastasis. DDR1 deficiency led to reduced expression of the genes encoding vascular endothelial growth factor (VEGF)-A, VEGF-C, and platelet-derived growth factor-B. These results suggest that DDR1 is involved in gastric cancer tumor progression and that silencing of DDR1 inhibits multiple steps of the gastric cancer metastasis process.

We previously reported that in an orthotopic nude mouse model of human colon cancer, bone marrow–derived mesenchymal stem cells (MSCs) migrated to the tumor stroma and promoted tumor growth and metastasis. Here, we evaluated the proliferation and migration ability of cancer cells cocultured with MSCs to elucidate the mechanism of interaction between cancer cells and MSCs. Proliferation and migration of cancer cells increased following direct coculture with MSCs but not following indirect coculture. Thus, we hypothesized that direct contact between cancer cells and MSCs was important. We performed a microarray analysis of gene expression in KM12SM colon cancer cells directly cocultured with MSCs. Expression of epithelial-mesenchymal transition (EMT)–related genes such as fibronectin (FN), SPARC, and galectin 1 was increased by direct coculture with MSCs. We also confirmed the upregulation of these genes with real-time polymerase chain reaction. Gene expression was not elevated in cancer cells indirectly cocultured with MSCs. Among the EMT-related genes upregulated by direct coculture with MSCs, we examined the immune localization of FN, a well-known EMT marker. In coculture assay in chamber slides, expression of FN was seen only at the edges of cancer clusters where cancer cells directly contacted MSCs. FN expression in cancer cells increased at the tumor periphery and invasive edge in orthotopic nude mouse tumors and human colon cancer tissues. These results suggest that MSCs induce EMT in colon cancer cells via direct cell-to-cell contact and may play an important role in colon cancer metastasis.