The FOXK1-CCDC43 Axis Promotes the Invasion and Metastasis of Colorectal Cancer Cells.

BACKGROUND/AIMS: The CCDC43 gene is conserved in human, rhesus monkey, mouse and zebrafish. Bioinformatics studies have demonstrated the abnormal expression of CCDC43 gene in colorectal cancer (CRC). However, the role and molecular mechanism of CCDC43 in CRC remain unknown. METHODS: The functional role of CCDC43 and FOXK1 in epithelial-mesenchymal transition (EMT) was determined using immunohistochemistry, flow cytometry, western blot, EdU incorporation, luciferase, chromatin Immunoprecipitation (ChIP) and cell invasion assays. RESULTS: The CCDC43 gene was overexpressed in human CRC. High expression of CCDC43 protein was associated with tumor progression and poor prognosis in patients with CRC. Moreover, the induction of EMT by CCDC43 occurred through TGF-ß signaling. Furthermore, a positive correlation between the expression patterns of CCDC43 and FOXK1 was observed in CRC cells. Promoter assays demonstrated that FOXK1 directly bound and activated the human CCDC43 gene promoter. In addition, CCDC43 was necessary for FOXK1- mediated EMT and metastasis in vitro and vivo. Taken together, this work identified that CCDC43 promoted EMT and was a direct transcriptional target of FOXK1 in CRC cells. CONCLUSION: FOXK1-CCDC43 axis might be helpful to develop the drugs for the treatment of CRC.

The accuracy of confocal laser endomicroscopy, narrow band imaging, and chromoendoscopy for the detection of atrophic gastritis.

OBJECTIVE: The aim of this study was to compare chromoendoscopy (CE), narrow band imaging (NBI), and confocal laser endomicroscopy (CLE) in diagnosing atrophic gastritis. BACKGROUNDS: Atrophic gastritis, especially metaplastic atrophy, has been shown to be a risk factor for gastric cancer. Some advanced endoscopic techniques have been used to diagnose atrophic gastritis. However, it is still difficult to diagnose atrophy with a high degree of accuracy. STUDY: In total, 253 gastric sites from 87 consecutive patients were examined by NBI, CE, and CLE, and in turn endoscopic diagnoses were made. Histologic diagnoses of biopsies taken from the observed sites served as gold standards. Comparisons were made of the sensitivity, specificity, and accuracy between each endoscopic technique for obtaining a diagnosis atrophic gastritis. RESULTS: NBI was found to be equivalent to CE in classifying gastric pits (κ=0.904). The CLE had a higher sensitivity (P=0.035), specificity (P=0.049), and accuracy (P=0.002) than CE for diagnosing atrophic gastritis. The sensitivity and specificity of CLE for diagnosing nonmetaplastic atrophy were 86.76% and 91.89%, respectively, and for metaplastic atrophy were 91.94% and 96.86%, respectively. Interobserver and intraobserver agreements of CLE for predicting histopathologic gastritis were both high (0.938 and 0.895, respectively). CONCLUSIONS: CLE is reliable for real-time assessment of atrophic gastritis and is also able to differentiate metaplastic from nonmetaplastic atrophy.

STK11 domain XI mutations: candidate genetic drivers leading to the development of dysplastic polyps in Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome (PJS) is a rare hereditary disorder resulting from mutations in serine/threonine kinase 11 (STK11) and characterized by gastrointestinal (GI) hamartomatous polyps, mucocutaneous pigmentation, and an increased risk for specific cancers. Little is known about the genetic implications of specific STK11 mutations with regard to their role in dysplastic and malignant transformation of GI polyps. Peripheral blood genomic DNA samples from 116 Chinese PJS patients from 52 unrelated families were investigated for STK11 mutations. Genotype-phenotype correlations were investigated. The mutation detection rate was 67.3% (51.9% point mutations, 15.4% large deletions). Fourteen out of the 25 point mutations identified were novel. Nearly one-third of all mutations, 8/27 (29.6%), were in exon 7, the shortest out of the nine exons. Strikingly, mutations affecting protein kinase domain XI, encoded in part by exon 7, correlated with a 90% (9/10) incidence of GI polyp dysplasia. In contrast, only two out of 17 (11.8%) nondomain XI mutations were linked to polyp dysplasia (P = 0.0001). The extent of the association between dysplasia and the development of GI-related cancers is currently unknown but our results highlight a novel STK11 genotype-phenotype association as the basis for future genetic counseling and basic research studies.

High risk and early onset of cancer in Chinese patients with Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disorder associated with a predisposition to a variety of cancers. Previous studies that have evaluated the cancer spectrum and risk of this rare disease have primarily been based on small data sets or heterogeneous cohorts from different countries. Here, we report the results of a large homogeneous cohort of Chinese PJS patients who were followed prospectively from 2006 to July 2021, and clinical data before 2006 were retrospectively collected. A total of 412 PJS patients (56.55% males) from 208 families were enrolled, contributing 12,798 person-years of follow-up. A total of 113 cancers were diagnosed in 109 patients (26.46%). The median age at the first cancer diagnosis was 40 years. In particular, patients born after the 1980s were diagnosed with cancer at an earlier median age of 30.5 years. The cumulative cancer risk was sharply increased to 30.9% at age 40 years; this high cancer risk age was 10 years earlier than that reported in previous Western studies, and increased to 76.2% at an age of 60 years. The most common cancer was gastrointestinal (GI) cancer (64.6%), in which colorectal cancer constituted a significantly larger proportional distribution (32.74%), when compared with previous investigations (11.1%-20.83%). There was some evidence that overrepresentation point variants in domain XI of STK11 may be associated with GI cancers. Furthermore, the incidences of gynecological and lung cancers were second only to that of GI cancer in this cohort. These results may provide novel insight for justifying surveillance to detect cancers at an earlier phase to improve clinical outcomes. Furthermore, the potential STK11 genotype-phenotype association could be the basis for future genetic counseling.

Clinicopathological features and outcomes of esophageal lesions containing a basal layer type squamous cell carcinoma component.

PURPOSE: Basal layer type squamous cell carcinoma (BLSCC) is a unique type of squamous cell carcinoma (SCC), characterized by high-grade dysplastic cells occupying the lower half of the epithelium. So far, such special lesions do not seem to attract much attention. The aim of this study was to investigate the clinicopathological features and prognosis of esophageal squamous carcinoma lesions with a BLSCC component. MATERIALS AND METHODS: Between January 2011 and January 2018, 96 patients with esophageal squamous cell carcinoma underwent endoscopic submucosal resection in our hospital were retrospectively analyzed. Patients were divided into BLSCC or typical SCC groups according to the presence or absence of a BLSCC component. The endoscopic findings were compared between the two groups. Furthermore, patients were followed up until October 2018 to compare recurrence rates. RESULTS: BLSCC components were detected in 32 (33.3%, 32/96) lesions. Among them, 13 (40.62%, 13/32) were BLSCC predominant. The intraepithelial papillary capillary loops of 7 pure BLSCC showed type B1 under narrow-band imaging. Single-factor and multivariate analyses indicated that five or more independently scattered, deep-stained spots in iodine-unstained areas were significantly predictive of the presence of BLSCC components (OR=4.837, P=0.015). All patients of typical SCC group survived, but one of BLSCC group died for distant metastases during the follow-up period. The 1-year cumulative recurrence rate (CRR) of BLSCC group were 3.4%, lower than that of typical SCC group (7.1%). Although no significant difference of CRR was seen between the two groups (P>0.05), the 2-year CRR of BLSCC group increased to 11.9%, being higher than that of typical SCC group (7.1%). CONCLUSION: The presence of multiple, scattered stained spots in iodine-unstained areas was predictive of BLSCC components. Such lesion should be treated actively and subject to a more rigorous follow-up protocol due to a higher likelihood of late recurrence.

Two novel STK11 missense mutations induce phosphorylation of S6K and promote cell proliferation in Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome (PJS) is a rare hereditary disease caused by mutations in serine threonine kinase 11 (STK11) and characterized by an increased risk of developing cancer. Inactivation of STK11 has been associated with the mammalian target of rapamycin (mTOR) pathway. Hyperactivation and phosphorylation of the key downstream target genes ribosomal protein S6 kinase 1 (S6K1) and S6 promote protein synthesis and cell proliferation. To better understand the effects of STK11 dysfunction in the pathogenesis of PJS, genomic DNA samples from 21 patients with PJS from 11 unrelated families were investigated for STK11 mutations in the present study. The results revealed 6 point mutations and 2 large deletions in 8 (72.7%, 8/11) of the unrelated families. Notably, 3 novel mutations were identified, which included 2 missense mutations [c.88G>A (p.Asp30Asn) and c.869T>C (p.Leu290Pro)]. Subsequent immunohistochemical analysis revealed staining for phosphorylated-S6 protein in colonic hamartoma and breast benign tumor tissues from patients with PJS carrying the two respective missense mutations. Additionally, the novel missense STK11 mutants induced phosphorylation of S6K1 and S6, determined using western blot analysis, and promoted the proliferation of HeLa and SW1116 cells, determined using Cell Counting Kit-8 and colony formation assays. Collectively, these findings extend the STK11 mutation spectrum and confirm the pathogenicity of two novel missense mutations. This study represents a valuable insight into the molecular mechanisms implicated in the pathogenesis of PJS.

[LKB1 regulates epithelial-mesenchymal transition in Peutz-Jeghers hamartoma and intestinal epithelial cells].

OBJECTIVE: To investigate the molecular mechanism by which LKB1 regulates epithelial-mesenchymal transition (EMT) in Peutz-Jeghers hamartoma and intestinal epithelial cells. METHODS: Immunohistochemistry was used to detect gene expression of LKB1, E-cadherin, and vimentin in 20 hamartoma tissues and 10 normal intestinal tissues, and collagen fiber deposition was analyzed using Masson trichrome staining. Normal intestinal epithelial NCM460 cells were transfected with LKB1 shRNA plasmid or negative control via lentiviral vectors, and the role of LKB1 in cell polarization and migration were determined using CCK8 and Transwell assays. Western blotting, quantitative real-time PCR (qPCR) and immunofluorescence were used to assess the alterations of EMT markers in the cells with LKB1 knockdown. RESULTS: Compared with normal intestinal tissues, hamartoma polyps showed significantly decreased LKB1 and E-cadherin expressions and increased vimentin expression with increased collagen fiber deposition. The cells with LKB1 knockdown exhibited enhanced cell proliferation and migration activities (P<0.01). Western blot analysis, qPCR and immunofluorescence all detected decreased E-cadherin and increased N-cadherin, vimentin, Snail, and Slug expressions in the cells with LKB1 knockdown. CONCLUSION: s LKB1 deficiency triggers EMT in intestinal epithelial cells and Peutz-Jeghers hamartoma, suggesting that EMT can serve as the therapeutic target for treatment of Peutz-Jeghers syndrome.

[Sample targeting under stereomicroscopy can raise the detection rate of early colorectal cancer].

OBJECTIVE: To establish a set of pathological diagnosis method to raise the detection rate of early colorectal cancer. METHODS: All patients with colorectal tumor underwent ordinary electron enteroscopy in 2005. The lesions larger than 10 mm underwent indigo carmine staining and magnifying electron enteroscopy to observe the pit pattern. Endoscopic mucosal resection (EMR) or endoscopic piecemeal resection (EPMR) was performed on the suspected cases of cancer, such as laterally spreading tumor (LST). The resected specimens were stained with cresyl violet and observed by stereomicroscopy to determine the pit patterns. The parts showing the pit patterns associated with early colorectal cancer were targeted and biopsy specimens collected here to undergo pathohistological examination. Routine pathological examination was conducted on the other parts of the same specimen as control. The results of these specimens were compared with those of the specimens collected by ordinary methods from the patients with colorectal tumor in 2004. RESULTS: In 2005 40 patients with colorectal tumor were suspected as with cancer and underwent EMR or EPMR of which 16 were confirmed to be with early stage colorectal cancer, including severe dysplasia by sampling targeting (40%). And the routine pathohistological examination of the randomly collected parts from these same specimens showed 15 cases of mild or moderate dysplasia and only one case of severe dysplasia, with a detection rate of 2.5%, significantly lower than that of the result of sample targeting under stereomicroscopy (P < 0.01). In 2004, out of the 54 patients suspected to be with colorectal cancer only 4 cases of early cancer, including severe dysplasia were detected with a detection rate of 7.4%, significantly than that of the year 2005 (P < 0.01). CONCLUSION: Sample targeting and localized biopsy under stereomicroscopy raises the detection rate of early colorectal cancer.

Suppression of KLF8 induces cell differentiation and sensitizes colorectal cancer to 5-fluorouracil.

KLF8 is a member of the KLF transcription factor family that plays an important role in oncogenesis. However, the role of KLF8 in colorectal cancer remains unknown. The aims of the present study were to examine KLF8 expression in colorectal cancers, to determine the role of KLF8 in cell differentiation and to investigate the antiproliferative effect of KLF8 silencing. The expression of KLF8 and phospho-ERK proteins was analyzed, and the effects of KLF8 suppression on cell differentiation and growth were evaluated. In addition, the biological impact of KLF8 knockdown on colorectal cancer cells was investigated in vitro and in vivo. The expression of the KLF8 protein was higher in 10/14 (71.43%) fresh cancer tissues compared with adjacent normal tissues, and the blockade of ERK signaling by U0126 decreased the expression of KLF8 in a time- and dose-dependent manner. Furthermore, KLF8-siRNA induced the expression of carcinoembryonic antigen (CEA) and E-cadherin as well as the maturation of F-actin. KLF8 suppression inhibited serum-dependent, anchorage­dependent and -independent cell growth. Moreover, KLF8 silencing induced apoptosis and sensitized cancer cells to 5-fluorouracil (5-FU). A strong antitumorigenic effect by lenti-KLF8-shRNA, which was enhanced when combined with 5-FU treatment, was exerted in nude mice. Thus, KLF8 suppression induced cell differentiation and inhibited tumorigenesis.

Training in early gastric cancer diagnosis improves the detection rate of early gastric cancer: an observational study in China.

Few studies have analyzed the training of endoscopists in the diagnosis of early gastric cancer (EGC). This study assessed whether specific training of endoscopists improves the detection rate of EGC. The rates of detection of EGC by endoscopists at the Digestive Endoscopy Center of the Affiliated Nanfang Hospital of China Southern Medical University between January 2013 and May 2014 were retrospectively analyzed. Because some endoscopists received training in the diagnosis of EGC, beginning in September 2013, the study was divided into 3 time periods: January to September 2013 (period 1), September 2013 to January 2014 (period 2), and January to May 2014 (period 3). The rates of EGC detection during these 3 periods were analyzed. From January 2013 to May 2014, a total of 25,314 gastroscopy examinations were performed at our center, with 48 of these examinations (0.2%) detecting EGCs, accounting for 12.1% (48/396) of the total number of gastric cancers detected. The EGC detection rates by trained endoscopists during periods 1, 2, and 3 were 0.3%, 0.6%, and 1.5%, respectively, accounting for 22.0%, 39.0%, and 60.0%, respectively, of the gastric cancers detected during these time periods. In comparison, the EGC detection rates by untrained endoscopists during periods 1, 2, and 3 were 0.05%, 0.08%, and 0.10%, respectively, accounting for 3.1%, 6.0%, and 5.7%, respectively, of the gastric cancers detected during these times. After training, the detection rate by some trained endoscopists markedly increased from 0.2% during period 1 to 2.3% during period 3. Further, the use of magnifying endoscopy with narrow-band imaging (M-NBI) (odds ratio = 3.1, 95% confidence interval 2.4-4.1, P < 0.001) contributed to the diagnosis of EGC. In conclusion, specific training could improve the endoscopic detection rate of EGC. M-NBI contributed to the diagnosis of EGC.

[CD133(+) Colo205 colorectal cancer cells express high levels of ALDH1 in serum-free culture].

OBJECTIVE: To investigate the expression pattern of CD133 and ALDH1 in colorectal cancer cells line Colo205 cultured in serum-free medium (SFM) containing recombinant human epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). METHODS: Colo205 cells were cultured in serum-free medium (SFM) containing human recombinant EGF and bFGF or in serum-supplemented medium (SSM). The expression of CD133 was analyzed in both groups, and CD133(+) and CD133(-) cells sorted from the SFM group using flow cytometry and observed microscopically for their growth status. The expression of CD133 and ALDH1 in CD133(+) cells and CD133(-) cells was detected by immunofluorescence assay. CD133(+) cells and CD133(-) cells were then injected subcutaneously into NOD/SCID mice and the expression of ALDH1 in the tumor tissues was detected by immunohistochemistry. RESULTS: The cells in SFM group showed a significantly higher percentage of CD133(+) cells than those in SSM group (P<0.05). In SFM, CD133(+) cells were capable of forming tumor spheres while CD133(-) cells could not; CD133(+)cells strongly expressed CD133 and ALDH1 and CD133(-) cells did not. In mice, tumors generated by CD133(+) cells, but not by CD133(-) cells, positively expressed ALDH1. CONCLUSIONS: CD133(+) Colo205 colorectal cancer cells in SFM containing human recombinant EGF and bFGF can form tumor spheres and strongly express ALDH1. ALDH1 may be one of the candidate markers of colorectal cancer stem cells.

Identification of kininogen-1 as a serum biomarker for the early detection of advanced colorectal adenoma and colorectal cancer.

BACKGROUND: Serum markers represent potential tools for the detection of colorectal cancer (CRC). The aim of this study was to obtain proteomic expression profiles and identify serum markers for the early detection of CRC. METHODS: Proteomic profiles of serum samples collected from 35 healthy volunteers, 35 patients with advanced colorectal adenoma (ACA), and 40 patients with CRC were compared using Clinprot technology. Using enzyme-linked immunosorbent assays (ELISAs), 366 sera samples were additionally analyzed, and immunohistochemistry studies of 400 tissues were used to verify the expression of kininogen-1 and its value in the early detection of CRC. RESULTS: Predicting models were established among the three groups, and kininogen-1 was identified as a potential marker for CRC using Clinprot technology. ELISAs also detected significantly higher serum kininogen-1 levels in ACA and CRC patients compared to controls (P<0.05). Furthermore, the area under the receiver operating characteristic curve (AUC) for serum kininogen-1 in the diagnosis of ACA was 0.635 (P=0.003), and for serum carcinoembryonic antigen (CEA) was 0.453 (P=0.358). The sensitivity, specificity, and accuracy of serum kininogen-1 for diagnosing Duke's stage A and B CRC was 70.13%, 65.88%, and 67.90%, respectively, whereas serum CEA was 38.96%, 85.88%, and 63.58%, respectively. Moreover, immunohistochemistry showed that expression of kininogen-1 was significantly higher in CRC and ACA tissues than in normal mucosa (48.39% vs. 15.58% vs. 0%, P<0.05). CONCLUSIONS: These results suggest that Clinprot technology provides a useful tool for the diagnosis of CRC, and kininogen-1 is a potential serum biomarker for the early detection of advanced colorectal adenoma and CRC.

Low molecular weight heparin relieves experimental colitis in mice by downregulating IL-1ß and inhibiting syndecan-1 shedding in the intestinal mucosa.

Low molecular weight heparin (LMWH) exhibits anti-inflammatory properties, but its effect on inflammation in colitis remains unclear. This study aimed to evaluate the therapeutic effects of LMWH on dextran sulfate sodium (DSS)-induced colitis in mice, in which acute colitis progresses to chronic colitis, and to explore the potential mechanism involved in this process. C57BL/6 mice were randomly divided into control, DSS, and DSS plus LMWH groups (n = 18). Disease activity was scored by a disease activity index (DAI). Histological changes were evaluated by hematoxylin and eosin (HE) staining. The mRNA levels of syndecan-1, interleukin (IL)-1ß, and IL-10 were determined by quantitative reverse transcription polymerase chain reaction. Protein expression of syndecan-1 was detected by immunohistochemistry. The serum syndecan-1 level was examined by a dot immunobinding assay. LMWH ameliorated the disease activity of colitis induced by DSS administration in mice. Colon destruction with the appearance of crypt damage, goblet cell loss, and a larger ulcer was found on day 12 after DSS administration, which was greatly relieved by the treatment of LMWH. LMWH upregulated syndecan-1 expression in the intestinal mucosa and reduced the serum syndecan-1 level on days 12 and 20 after DSS administration (P<0.05 vs. DSS group). In addition, LMWH significantly decreased the expression of both IL-1ß and IL-10 mRNA on days 12 and 20 (P<0.05 vs. DSS group). LMWH has therapeutic effects on colitis by downregulating inflammatory cytokines and inhibiting syndecan-1 shedding in the intestinal mucosa.

[Changes in the biological behaviors of colon cancer cells under simulated hypoxia in vitro].

OBJECTIVE: To investigate the reactivity of colon cancer cell line SW480 and CD133(+) SW480 subsets to hypoxia in vitro and the changes in the expressions of anti-apoptosis and angiogenesis genes. METHODS: SW480 cells was subjected to CoCl(2) exposure at varying concentrations and for different time lengths to induce hypoxia, and the protein expression of hypoxia induced factor 1α (HIF-1α) was detected by Western blotting. The CD133(+) SW480 cells were sorted by magnetic activated cell sorting (MACS) and their proportion was assayed by flow cytometry (FCM). The CD133(+) SW480 subsets were exposed to CoCl(2) at the optimal concentration with exposure time selected in terms of HIF-1α level, and their tumor stem cell sphere formation ability was evaluated. Real-time PCR was used to compare the mRNA expression levels of the surface markers of colon cancer stem cells (CD133 and PROM1), survivin, and vascular endothelial growth factor (VEGF). RESULTS: Exposure to 200 µmol/L CoCl(2) for 8 h resulted in the highest HIF-1α expression in SW480 cells, but the same exposure failed to induce HIF-1α expression in CD133(+) SW480 subsets. The CD133(+) SW480 subsets, after CoCl(2)-induced hypoxia, showed significantly enhanced ability of cell sphere formation. Hypoxia of SW480 cells caused significant increases in CD133, survivin and VEGF mRNA levels by 1.607∓0.103, 2.745∓0.370 and 3.798∓0.091 folds, respectively (P<0.05). CONCLUSION: CoCl(2) can simulate hypoxia in colon cancer cells in vitro to induce stable HIF-1α expression, which is concentration- and time-dependent. The hypoxia-stimulated tumor stem sells show an enhanced sphere formation and anti-apoptotic and anti-angiogenic abilities.

Effects of sea buckthorn procyanidins on healing of acetic acid-induced lesions in the rat stomach.

The aim of this study was to investigate the effects of sea buckthorn procyanidins (SBPC) on healing of acetic acid-induced lesions in the rat stomach and its possible mechanism. The sea buckthorn procyanidins (SBPC) were extracted with 60% alcohol/H2O from sea buckthorn bark and purified by macropore adsorption resin column, with a purity of >96%. The chemical character of SBPC was analyzed by reverse phase high-performance liquid chromatography/mass spectrometry (HPLC/MS). Chronic gastric ulceration was induced by injecting acetic acid into the subserosa of stomach. Different concentrations of SBPC were orally administrated to gastric ulcers rats. After treatment 7d and 14d, rats were sacrificed respectively. The healing of the acetic acid induced ulcerations was measured by ulcer index (UI). The level of epidermal growth factor (EGF) in plasma was determined; the expression of epidermal growth factor receptor (EGFR) and proliferating cell nuclear antigen (PCNA) around ulcer was detected by immunohistochemical method. SBPC was found to reduce the size of the ulcers at day 7 and 14 in a dose-dependent manner. Compared with the control, the UI of SBPC group was significantly lower (p< 0.01) and the level of EGF in the plasma of SBPC group increased significantly (p< 0.01), meanwhile the expression of EGFR and PCNA around ulcer in high-dose SBPC stomach were enhanced (p< 0.05). The results implied that SBPC plays an important role in healing of acetic acid-induced gastric lesions possibly by the acceleration of the mucosal repair.