Mir-4746 inhibits the proliferation of colorectal cancer cells in vitro and in vivo by targeting CCND1.

Colorectal cancer (CRC) is a commonly seen malignant tumor manifesting itself in the digestive tract, but it remains unclear what is the molecular mechanism behind its occurrence and development, which can have a significant impact on the clinical diagnosis and treatment of CRC. According to some studies, microRNA (miRNA) plays an essential role in the occurrence and development of cancer. In spite of this, there are still many miRNAs that play an important role in the progression of CRC but have yet to be reported. In our research, it was found out that the expression of mir-4746 is significantly down-regulated in CRC tissues and cells, and that its expression level is closely associated with the tumor size and prognosis of clinical patients. As revealed by function and mechanism experiments, targeting CCND1 mRNA 3'-UTR, mir-4746 can promote the degradation of CCND1 mRNA, thus reducing the protein level of CCND1, leading to cell G0-G1 phase arrest, and ultimately inhibiting the proliferation of CRC cells. For the first time, our study reported the biological functions of mir-4746 and its preliminary mechanism of action, in addition to demonstrating that mir-4746 can be applied as both a potential prognostic marker and the therapeutic target for CRC.

Discovery of 4-methoxy-N-(1-naphthyl)benzenesulfonamide derivatives as small molecule dual-target inhibitors of tubulin and signal transducer and activator of transcription 3 (STAT3) based on ABT-751.

Overexpressed tubulin and continuously activated STAT3 play important roles in the development of many cancers and are potential therapeutic targets. A series of 4-methoxy-N -(1-naphthalene) benzenesulfonamide derivatives were designed and optimized based on ß-tubulin inhibitor ABT-751 to verify whether STAT3 and tubulin dual target inhibitors have better antitumor effects. Compound DL14 showed strong inhibitory activity against A549, MDA-MB-231 and HCT-116 cells in vitro with IC50 values of 1.35 µM, 2.85 µM and 3.04 µM, respectively. Further experiments showed that DL14 not only competitively bound to colchicine binding site to inhibit tubulin polymerization with IC50 values 0.83 µM, but also directly bound to STAT3 protein to inhibit STAT3 phosphorylation with IC50 value of 6.84 µM. Three other compounds (TG03, DL15, and DL16) also inhibit this phosphorylation. In terms of single target inhibition, DL14 is slightly inferior to positive drugs, but it shows a good anti-tumor effect in vivo, and can inhibit >80% of xenograft tumor growth. This study describes a novel 4-methoxy-N-(1-naphthyl) benzenesulfonamide skeleton as an effective double-targeted anticancer agent targeting STAT3 and tubulin.

Interplay between Trx-1 and S100P promotes colorectal cancer cell epithelial-mesenchymal transition by up-regulating S100A4 through AKT activation.

We previously reported a novel positive feedback loop between thioredoxin-1 (Trx-1) and S100P, which promotes the invasion and metastasis of colorectal cancer (CRC). However, the underlying molecular mechanisms remain poorly understood. In this study, we examined the roles of Trx-1 and S100P in CRC epithelial-to-mesenchymal transition (EMT) and their underlying mechanisms. We observed that knockdown of Trx-1 or S100P in SW620 cells inhibited EMT, whereas overexpression of Trx-1 or S100P in SW480 cells promoted EMT. Importantly, S100A4 and the phosphorylation of AKT were identified as potential downstream targets of Trx-1 and S100P in CRC cells. Silencing S100A4 or inhibition of AKT phosphorylation eliminated S100P- or Trx-1-mediated CRC cell EMT, migration and invasion. Moreover, inhibition of AKT activity reversed S100P- or Trx-1-induced S100A4 expression. The expression of S100A4 was higher in human CRC tissues compared with their normal counterpart tissues and was significantly correlated with lymph node metastasis and poor survival. The overexpression of S100A4 protein was also positively correlated with S100P or Trx-1 protein overexpression in our cohort of CRC tissues. In addition, overexpression of S100P reversed the Trx-1 knockdown-induced inhibition of S100A4 expression, EMT and migration and invasion in SW620 cells. The data suggest that interplay between Trx-1 and S100P promoted CRC EMT as well as migration and invasion by up-regulating S100A4 through AKT activation, thus providing further potential therapeutic targets for suppressing the EMT in metastatic CRC.

MiR-186-5p upregulation inhibits proliferation, metastasis and epithelial-to-mesenchymal transition of colorectal cancer cell by targeting ZEB1.

MicroRNA-186-5p (miR-186-5p) is upregulated and exhibits as a crucial oncogene in various human tumors. However, the functions and underlying mechanisms of this microRNA on colorectal cancer remain largely unknown. Here, we report that miR-186-5p share a lower expression in colorectal cancer cell lines (HT116, H29, SW620 and LoVo) than in normal colonic epithelial cell line NCM460. MiR-186-5p overexpression inhibits proliferation, metastasis and epithelial-to-mesenchymal transition (EMT) of colorectal cancer cell line LoVo. Zinc Finger E-Box Binding Homeobox 1 (ZEB1), an EMT related marker, is predicted as a target of miR-186-5p. Luciferase reporter assay, qRT-PCR and western blot analysis showed that miR-186-5p directly targeted the 3'-untranslated regions (3'UTR) of ZEB1 messenger RNA. Further functional experiments indicated that overexpression of miR-186-5p suppress the proliferation and metastasis ability of LoVo, which was consistent with the inhibitory effects by knockdown of ZEB1. Additionally, overexpression of ZEB1 could significantly reverse the miR-186-5p mimics initiated suppression impact of proliferation, metastasis and EMT on LoVo. In summary, miRNA-186-5p affects the proliferation, metastasis and EMT process of colorectal cancer cell by inhibition of ZEB1. Hence, it may serve as a promising therapeutic target for colorectal cancer.

Identification of differentially expressed circular RNAs in human colorectal cancer.

Circular RNA, a class of non-coding RNA, is a new group of RNAs and is related to tumorigenesis. Circular RNAs are suggested to be ideal candidate biomarkers with potential diagnostic and therapeutic implications. However, little is known about their expression in human colorectal cancer. In our study, differentially expressed circular RNAs were detected using circular RNA array in paired tumor and adjacent non-tumorous tissues from six colorectal cancer patients. Expression levels of selected circular RNAs (hsa_circRNA_103809 and hsa_circRNA_104700) were measured by real-time polymerase chain reaction in 170 paired colorectal cancer samples for validation. Statistical analyses were conducted to investigate the association between hsa_circRNA_103809 and hsa_circRNA_104700 expression levels and respective patient clinicopathological features. Receiver operating characteristic curve was constructed to evaluate the diagnostic values. Our results indicated that there were 125 downregulated and 76 upregulated circular RNAs in colorectal cancer tissues compared with normal tissues. We also first demonstrated that the expression levels of hsa_circRNA_103809 ( p < 0.0001) and hsa_circRNA_104700 ( p = 0.0003) were significantly lower in colorectal cancer than in normal tissues. The expression level of hsa_circRNA_103809 was significantly correlated with lymph node metastasis ( p = 0.021) and tumor-node-metastasis stage ( p = 0.011), and the expression level of hsa_circRNA_104700 was significantly correlated with distal metastasis ( p = 0.036). The area under receiver operating characteristic curves of hsa_circRNA_103809 and hsa_circRNA_104700 were 0.699 ( p < 0.0001) and 0.616 ( p < 0.0001), respectively. In conclusion, these results suggest that hsa_circRNA_103809 and hsa_circRNA_104700 may be potentially involved in the development of colorectal cancer and serve as potential biomarkers for the diagnosis of colorectal cancer.

A CTL-Inspired Killing System Using Ultralow-Dose Chemical-Drugs to Induce a Pyroptosis-Mediated Antitumor Immune Function.

A Cytotoxic T lymphocyte-inspired system capable of using ultralow-dose chemical drugs to manipulate cell death is needed to investigate the antitumor immunotherapy. Recent studies reveal pyroptosis promotes antitumor immune function. However, high-dose chemotherapy leads to cytokine release syndrome by pyroptosis. Therefore, pyroptosis-inducing ultralow-dose chemotherapy is potential in preclinical and clinical research, but its efficacy, safety, and the antitumor immune responses are not clear. Here, a near-infrared light controllable killing system (BIK system) is established by which ultralow-dose doxorubicin can be spatiotemporally transported to tumor cells and mediate efficient pyroptosis. This BIK system reduces total drug consumption to less than one-thirtieth the common dose in vitro. Moreover, this BIK system exhibited good tumor targeting and tumor penetration. This system is applied for pyroptosis-induced antitumor therapies, which shows less than ≈25 µg kg-1 doxorubicin is sufficient for tumor regression with negligible injuries to major organs. The antitumor immune function are proven to correlate with the impressive efficacy of pyroptosis-inducing ultralow-dose chemotherapy. This study provides new insights into the design of nanoassisted systems for activating the antitumor immunity by microstimulation; the application of the BIK system suggests that ultralow-dose chemotherapy is sufficient for inducing a robust pyroptosis-mediated antitumor immunity.

Inhibition of DDR1 promotes ferroptosis and overcomes gefitinib resistance in non-small cell lung cancer.

Gefitinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), which serves the critical pillar for the treatment of non-small cell lung cancer (NSCLC). However, the acquired resistance remains a challenge for its clinical application, for which, practical strategies to reverse gefitinib resistance in NSCLC are necessary. Ferroptosis, a programmed cell death driven by ferritin-dependent lipid peroxidation, involves in NSCLC progression and related chemoresistance. In our previous work, the self-synthesised EGFR inhibitor Yfq07 (N4, N6-disubstituted pyrimidine-4,6-diamine derivatives) displayed a considerable inhibitory effect on NSCLC both in vitro and in vivo. Herein, we observed that Yfq07 suppressed the proliferation of PC-9GR and HCC827GR cells, two gefitinib resistance NSCLC cell lines. Mechanically, Yfq07 inhibited the phosphorylation of the Discoidin Domain Receptor 1 (DDR1), a receptor tyrosine kinase (RTK) highly expressed in multiple cancers, accompanied by downregulated miR-3648 and upregulated SOCS2. Inhibition or knockdown of DDR1 suppressed the proliferation, migration, and invasion of gefitinib-resistant NSCLC cells, and on the other hand, also downregulated miR-3648 and promoted SOCS2 expression. More specifically, miR-3648 targeted the 3'UTR segment of SOCS2 mRNA and thus affecting the P-ERK signalling pathway to regulate the malignant behaviors of gefitinib-resistant NSCLC cells. Furthermore, Yfq07 also indirectly induced the ferroptosis of gefitinib-resistant NSCLC cells via SOCS2 triggered inhibition of xCT-GPX4 pathway. In conclusion, our study indicates that DDR1 inhibitor Yfq07 promotes ferroptosis and reverses gefitinib-resistance of NSCLC through DDR1-miR-3648-SOCS2 signalling pathway, which provides insights for targeted therapy of gefitinib-resistant NSCLC and drug developments targeting ferroptosis.

Expression of ZNF148 in different developing stages of colorectal cancer and its prognostic value: a large Chinese study based on tissue microarray.

BACKGROUND: It has been speculated that zinc finger protein 148 (ZNF148) is a tumor suppressor. However, to the authors' knowledge, little is known about the clinical significance of ZNF148 expression in patients with colorectal cancer (CRC). The objective of the current study was to clarify the association between ZNF148 expression and the postoperative prognosis of patients with CRC. METHODS: Tissue microarrays containing 56 normal mucosa, 51 adenoma, 742 CRC (TNM stage I-IV), 16 familial adenomatous polyposis, and 21 metastatic CRC specimens were examined immunohistochemically for ZNF148 expression. RESULTS: Expression of ZNF148 was found to increase consecutively from normal mucosa to stage I CRC, and then decreased consecutively from stage I to stage IV CRC. Lower expression of ZNF148 in tumors was found to be significantly associated with lymph node metastases, advanced TNM disease stage, poor differentiation, higher rate of disease recurrence, worse overall survival (OS), and shorter disease-free survival. High expression of ZNF148 was also associated with improved OS (P = .025) and disease-free survival (P = .042) in patients with stages II to III CRC. On multivariate Cox analysis, lower ZNF148 expression in tumors, advanced TNM stage, colon cancer, and elevated serum carbohydrate antigen 19-9 (CA19-9) were found to be significant factors for a worse OS. In 16 patients with familial adenomatous polyposis, ZNF148 expression was upregulated at steps toward carcinogenesis. In 21 patients with metastatic CRC, although ZNF148 expression was higher in primary tumors compared with adjacent mucosa, its expression in metastatic tumors was significantly lower than that in primary tumors. CONCLUSIONS: Although ZNF148 expression is related to colorectal carcinogenesis, high ZNF148 expression in patients with CRC appears to be inversely associated with malignant phenotypes and may serve as a significant prognostic factor after surgery for patients with CRC.

A cytotoxic T cell inspired oncolytic nanosystem promotes lytic cell death by lipid peroxidation and elicits antitumor immune responses.

Lytic cell death triggers an antitumour immune response. However, cancer cells evade lytic cell death by several mechanisms. Moreover, a prolonged and uncontrolled immune response conversely leads to T-cell exhaustion. Therefore, an oncolytic system capable of eliciting an immune response by killing cancer cells in a controlled manner is needed. Here, we establish a micro-scale cytotoxic T-cell-inspired oncolytic system (TIOs) to precisely lyse cancer cells by NIR-light-controlled lipid peroxidation. Our TIOs present antigen-based cell recognition, tumour-targeting and catalytic cell-lysis ability; thus, the TIOs induce oncolysis in vivo. We apply TIOs to preclinical cancer models, showing anti-tumor activity with negligible side-effects. Tumour regression is correlated with a T-cell based anti-tumour immune response and TIOs also improve responses to anti-PD-1 therapy or STING activation. Our study provides insights to design oncolytic systems for antitumour immunity. Moreover, activation of STING can reverse T-cell exhaustion in oncolysis.

Sparse-to-dense coarse-to-fine depth estimation for colonoscopy.

Colonoscopy, as the golden standard for screening colon cancer and diseases, offers considerable benefits to patients. However, it also imposes challenges on diagnosis and potential surgery due to the narrow observation perspective and limited perception dimension. Dense depth estimation can overcome the above limitations and offer doctors straightforward 3D visual feedback. To this end, we propose a novel sparse-to-dense coarse-to-fine depth estimation solution for colonoscopic scenes based on the direct SLAM algorithm. The highlight of our solution is that we utilize the scattered 3D points obtained from SLAM to generate accurate and dense depth in full resolution. This is done by a deep learning (DL)-based depth completion network and a reconstruction system. The depth completion network effectively extracts texture, geometry, and structure features from sparse depth along with RGB data to recover the dense depth map. The reconstruction system further updates the dense depth map using a photometric error-based optimization and a mesh modeling approach to reconstruct a more accurate 3D model of colons with detailed surface texture. We show the effectiveness and accuracy of our depth estimation method on near photo-realistic challenging colon datasets. Experiments demonstrate that the strategy of sparse-to-dense coarse-to-fine can significantly improve the performance of depth estimation and smoothly fuse direct SLAM and DL-based depth estimation into a complete dense reconstruction system.

m(6)A demethylase ALKBH5 inhibits cell proliferation and the metastasis of colorectal cancer by regulating the FOXO3/miR-21/SPRY2 axis.

OBJECTIVE: Colorectal cancer is a common malignancy worldwide. This research aimed to investigate the role of α-ketoglutarate-dependent dioxygenase alkB homologue 5 (ALKBH5), a N6-methyladenosine (m(6)A) demethylase, on the cell proliferation and metastasis of colorectal cancer. METHODS: The interaction relationship between FOXO3, miR-21, and SPRY2 were predicted by starBase 2.0 and determined using RIP, CHIP, and dual-luciferase reporter assays. Quantitative reverse transcription PCR (RT-qPCR) and western blot were used to measure the gene and miRNA expressions of ALKBH5, FOXO3, miR-21, and SPRY2. The cell proliferation was determined using CCK8 and colony formation assays. The metastatic abilities were measured using wound healing and transwell assays. RESULTS: In colorectal cancer, downregulated ALKBH5 is related to poor prognosis. Rescued ALKBH5 suppresses the proliferation and metastasis of colorectal cancer cells. The role of ALKBH5 is achieved by reducing the m(6)A modification of forkhead box O3 (FOXO3), which enhances its stability. FOXO3 targets miR-21 and increases the SPRY2 expressions. The antitumor effects of ALKBH5 can be blocked by FOXO3 knockdown, which is reversed by the miR-21 inhibitor. CONCLUSION: ALKBH5 plays an antitumor role in colorectal cancer by regulating the FOXO3/miR-21/SPRY2 axis, providing a new direction for colorectal cancer therapy.

Discovery of N-substituted sulfamoylbenzamide derivatives as novel inhibitors of STAT3 signaling pathway based on Niclosamide.

Signal transducer and activator of transcription 3 (STAT3) has been confirmed as an attractive therapeutic target for cancer therapy. Herein, we designed and synthesized a series of N-substituted Sulfamoylbenzamide STAT3 inhibitors based on small-molecule STAT3 inhibitor Niclosamide. Compound B12, the best active compound of this series, was identified as an inhibitor of IL-6/STAT3 signaling with an IC50 of 0.61-1.11 µM in MDA-MB-231, HCT-116 and SW480 tumor cell lines with STAT3 overexpression, by inhibiting the phosphorylation of STAT3 of Tyr705 residue and the expression of STAT3 downstream genes, inducing apoptosis and inhibiting the migration of cancer cells. Furthermore, in vivo study revealed that compound B12 suppressed the MDA-MB-231 xenograft tumor growth in nude mice at the dose of 30 mg/kg (i.g.), which has better antitumor activity than the positive control Niclosamide. More importantly, B12 is an orally bioavailable anticancer agent as a promising candidate for further development.

[Value of protective stoma in intersphincteric resection for ultra-low rectal cancer].

OBJECTIVE: To investigate the value of protective stoma in intersphincteric resection (ISR) for ultra-low rectal cancer. METHODS: Clinical data of 56 ultra-low rectal cancer patients without involvement of external anal sphincter treated during January 1999 to July 2009 with trans-anal ISR plus trans-abdominal total mesorectum excision and coloanal anastomosis were retrospectively analyzed. The patients were divided into two groups based on whether they received protective ostomy: ostomy group (16 cases) and ostomy-free group (40 cases). The postoperative complications as well as anal functional restoration were compared between the two groups. RESULTS: Sixteen cases (32.1%) of the 56 patients received protective stoma. The complication rate of anastomosis and anus complication rate in the ostomy-free group were significantly higher than those in ostomy group [35.0% (14/40) and 40.0% (16/40) vs. 1/16 and 1/16; P < 0.05]. In the ostomy-free group, one patient developed anastomotic dehiscence and tumor recurrence, the patients was given permanent colostomy, and the other three patients with lesions in the anastomosis and anus received ostomy and secondary surgical treatment, with a reoperation rate of 10.0% (4/40). The anal function of patients in the two groups were both decreased after the operation. The rate of patients got Kirwan grade I anal sphincter function in the 3rd, 6th and 12th month after protective stoma operation was 11/16, 13/15 and 11/13 in the ostomy group, respectively; and those were 30.0%, 37.5% and 45.0% in the ostomy-free group, respectively. Anal function was significantly better in the ostomy group than that in the ostomy-free group during the same postoperative period (P < 0.05). CONCLUSION: Protective stoma can avoid anastomotic leakage following ISR for ultra-low rectal cancer, and alleviate the suffering of anal incontinence in the early postoperative period, and is conducive to the restoration of anal function.

[Clinical application of intersphincteric resection in the anal-preserving operation for ultra-low rectal carcinoma].

OBJECTIVE: To investigate the clinical application of intersphincter resection (ISR) combined with total mesorectal excision (TME) and colon-anal anastomosis in the treatment for ultra-low rectal carcinoma. METHODS: To review and analyze retrospectively the data of 34 patients with ultra-low rectal carcinoma (without external anal sphincter involvement) who received treatment of ISR, TME and colon-anal anastomosis. RESULTS: Partial resection of internal sphincter was performed in the patients with a distal edge of the tumor greater than or equal to 2 cm from the dentate line. Subtotal removal of the rectum was performed between 1 cm and 2 cm. Total resection was performed in less than 1 cm or involvement of dentate line. Reconstruction of digestive tract was done by manual colon-anal anastomosis. The average distance from distal excised margin to the tumor was 2.3 (1.8 - 3.2) cm among 34 patients. The pathological types were as follows: 28 cases of adenocarcinoma (11 were well differentiated, 17 moderately differentiated), 1 case of papillary carcinoma and 5 cases of villous adenoma with malignant change. The postoperative pathological stages were: Dukes stage A in 28 cases, stage B in 1 and stage C in 5 cases. The pTNM staging was 28 cases in phase I, 1 in phase IIa, 4 in phase IIIa and 1 in phase IIIb. The T stages of the patients were as following: 16 Tl, 17 T2 and 1 T3. Postoperative anastomotic stenosis occurred in 3 cases, anastomotic dehiscence in 2 cases and rectovaginal fistula in 2 cases. The ability of controlling feces of patients decreased significantly in the early postoperative period, and restored gradually at 6 to 12 months after operation. Anastomotic recurrence occurred in 1 case at 5 months after operation and liver metastasis in 1 case at 40 months. CONCLUSION: With strictly grasping indications, radical resection can be attained and anal sphincter preserved by ISR combined with TME and colon-anal anastomosis. It is an effective sphincter-preserving operation.

[Combination of trans-anal intersphincteric resection and trans-abdominal total mesorectal excision for anus-retained ultra-low rectal tumors].

OBJECTIVE: To study the combination of trans-anal intersphincteric resection and transabdominal total mesorectal excision for anus-retained ultra-low rectal tumors. METHODS: Clinical data of 34 ultra-low rectal tumor patients without external anal sphincter involved, who underwent the combination surgery, were retrospectively analyzed. RESULTS: The distance from the distal incisal margin of the rectum to the inferior margin of the tumor ranged from 1.8 cm to 3.0 cm on an average of 2.1 cm. For pathological types, there were 23 cases of adenocarcinoma (9 well differentiated and 14 moderately differentiated), 1 papillary carcinoma, 2 rectal stromal tumor, 5 rectal villous adenoma with neoplasia and 3 giant villous adenoma. For pathological stages, there were 18 cases at stage pTNM I, 5 at IIA, 1 at IIB, 4 at IIIA, 1 at III and for T grading, there were 15 cases at stage T1, 5 at T2, 8 at T3, 1 at T4. In these 34 patients, there were 3 cases with postoperative anastomotic stenosis, 2 with postoperative anastomotic rupture, 2 with rectovaginal fistula and no operative death. Because of the dysfunction of bowel control, bowel frequency varied from 3 to 12 in the early stage after operation, but with the recovery of anus function, bowel frequency decreased and ranged form 1 to 5 times a day and the time of formed bowel control could be more than 5 min in 6-12 months after operation. However, patients underwent total resection of internal anal sphincter still suffered from incontinence of loose stool after 1 year. After operation, anastomotic recurrence was found in 1 case in 5 months, liver metastasis in 1 case in 10 months and 28 months respectively, cardiac sudden death in 1 case in 26 months. CONCLUSION: The combination of trans-anal ISR and trans-abdominal TME for anus-retained ultra low rectal tumor is not only coincident with radical tumor principle but also retains the function of anus, on the premise of the strict indication.

Collagen facilitates the colorectal cancer stemness and metastasis through an integrin/PI3K/AKT/Snail signaling pathway.

PURPOSE: Dynamic remodeling of the extracellular matrix (ECM) around tumor cells is crucial for the tumor progressions. However, the mechanism is not well defined. Here, we aimed to reveal the underlying mechanism of ECM induced metastasis and provide innovative strategy to suppress the distant metastasis induced by ECM. MATERIALS AND METHODS: IHC was used to detect the expression of target proteins. H&E staining was used to evaluate the growth of tumor in vivo. Using wound healing and transwell assay, we examined the ability of cell to metastasis. We employed IF and Western blot to detect the expression of target proteins. And qRT-PCR was used to examine the target genes in mRNA level. We also applied flow cytometry to examine the percent of CD133+ cell population. RESULTS: Herein, we observed elevated expression of type I collagen in colorectal cancer tissues from patients with high metastasis. Additionally, colorectal cancer cells cultured on 2D collagen reveal obviously enhanced capability of metastasis and tumorigenesis both in vitro and in vivo. We demonstrated that the activation of PI3K/AKT signal induced by integrin α2ß1 resulted in the enhanced metastatic capability and stemness of colorectal cancer cells. Moreover, we found that Snail worked as the downstream of PI3K/AKT signaling, resulting in the intensive invasion and metastasis of colorectal cancer. Blocking the pathway by applying E7820 successfully reversed the type I collagen induced distant metastasis in colorectal cancer. CONCLUSION: Combining E7820 and chemotherapeutic agents to block the integrin α2ß1/PI3K/AKT/Snail signaling pathway revealed dramatic enhanced tumor suppression and provided an innovative approach for clinical colorectal cancer treatment.

MEG3 can affect the proliferation and migration of colorectal cancer cells through regulating miR-376/PRKD1 axis.

The down-regulation of long non-coding RNA (lncRNA) MEG3 has been observed in various cancers; nonetheless, underlying mechanisms are still unclear. The current research work aims at exploring the roles of MEG3 in the pathogenesis of CRC and the associated mechanism. We observed that MEG3 was significantly down-regulated in both CRC tumor tissue and cell lines; also, the transient over-expression of MEG3 in CRC cell line SW480 and LoVo inhibited the proliferation and the migration and clone formation capability of cells; on the other hand, the knockdown of MEG3 has revealed opposite effects. Eventually, we figured it out that target miR-376 directly targeted both MEG3 and PRDK1 in SW480 and LoVo cells. To conclude, as our findings proved, MEG3 is likely to act as a tumor suppressor in the pathogenesis of CRC by means of the regulation of the miR-376/PRDK1 signal axis, suggesting that MEG3 has the potential to become a novel therapeutic target for the treatment of CRC.

Flubendazole demonstrates valid antitumor effects by inhibiting STAT3 and activating autophagy.

BACKGROUND: Signal transducer and activator of transcription 3 (STAT3) is an oncogene, which upregulates in approximately 70% of human cancers. Autophagy is an evolutionarily conserved process which maintains cellular homeostasis and eliminates damaged cellular components. Moreover, the STAT3 signaling pathway, which may be triggered by cancer cells, has been implicated in the autophagic process. METHODS: In this study, we found that the anthelmintic flubendazole exerts potent antitumor activity in three human colorectal cancer (CRC) cell lines and in the nude mouse model. The inhibition of cell proliferation in vitro by flubendazole was evaluated using a clonogenic assay and the MTT assay. Western blot analysis, flow cytometry analysis, siRNA growth experiment and cytoplasmic and nuclear protein extraction were used to investigate the mechanisms of inhibiting STAT3 signaling and activation of autophagy induced by flubendazole. Additionally, the expression of STAT3 and mTOR was analyzed in paired colorectal cancer and normal tissues collected from clinical patients. RESULTS: Flubendazole blocked the IL6-induced nuclear translocation of STAT3, which led to inhibition of the transcription of STAT3 target genes, such as MCL1, VEGF and BIRC5. In addition, flubendazole also reduced the expression of P-mTOR, P62, BCL2, and upregulated Beclin1 and LC3-I/II, which are major autophagy-related genes. These processes induced potent cell apoptosis in CRC cells. In addition, flubendazole displayed a synergistic effect with the chemotherapeutic agent 5-fluorouracil in the treatment of CRC. CONCLUSIONS: Taken together, these results indicate that flubendazole exerts antitumor activities by blocking STAT3 signaling and inevitably affects the autophagy pathway. Flubendazole maybe a novel anticancer drug and offers a distinctive therapeutic strategy in neoadjuvant chemotherapy of CRC.

Design, Synthesis, And Evaluation Of Cyanopyridines As Anti-Colorectal Cancer Agents Via Inhibiting STAT3 Pathway.

BACKGROUND: Colorectal cancer is one of the common malignant tumors. Cyanopyridine and aminocyanopyridine having a carbon-nitrogen bond have been shown to have significant anticancer effects. STAT3 is a promising therapeutic target in multiple cancers. However, there are currently no effective STAT3 inhibitors in clinical practice for the treatment of colorectal cancer. MATERIALS AND METHODS: We screened 27 cyanopyridines for their anticancer activity by cell viability. The HCT-116, RKO, and DLD-1 cell lines were used to evaluate the anti-colorectal cancer effect of 3n. Scratch experiments and colony formation assays were used for the assessment of cell migration and proliferation capacity. Phosphorylated STAT3, STAT3, MCL-1, and Survivin levels were assessed by Western blot analysis. RESULTS: In this study, we synthesized 27 cyanopyridines and screened their anticancer activities in three human tumor cells, HCT-116, Hela229, and A375. We found that 2-amino-3-cyanopyridine 3n has better anticancer activity with IC50 values in the low micromolar range. Furthermore, 3n significantly inhibited the migration and colony formation of colorectal cancer cells. Mechanistically, 3n inhibited the expression of STAT3 phosphorylation in a dose- and time-dependent manner. CONCLUSION: 3n is worth of further investigations toward the discovery of STAT3 inhibitor as a drug candidate for cancer therapy.

Colonic Lysine Homocysteinylation Induced by High-Fat Diet Suppresses DNA Damage Repair.

Colorectal cancer (CRC) onset is profoundly affected by Western diet. Here, we report that high-fat (HF) diet-induced, organ-specific colonic lysine homocysteinylation (K-Hcy) increase might promote CRC onset by impeding DNA damage repair. HF chow induced elevated methionyl-tRNA synthetase (MARS) expression and K-Hcy levels and DNA damage accumulation in the mouse and rat colon, resulting in a phenotype identical to that of CRC tissues. Moreover, the increased copy number of MARS, whose protein product promotes K-Hcy, correlated with increased CRC risk in humans. Mechanistically, MARS preferentially bound to and modified ataxia-telangiectasia and Rad3-related protein (ATR), inhibited ATR and its downstream effectors checkpoint kinase-1 and p53, and relieved cell-cycle arrest and decreased DNA damage-induced apoptosis by disrupting the binding of ATR-interacting protein to ATR. Inhibiting K-Hcy by targeting MARS reversed these effects and suppressed oncogenic CRC cell growth. Our study reveals a mechanism of Western-diet-associated CRC and highlights an intervention approach for reversing diet-induced oncogenic effects.