Inhibition of ubiquitin specific peptidase 8 is effective against 5-fluorouracil resistance in colon cancer via suppressing EGFR and EGFR-mediated signaling pathways.

BACKGROUND: The identification of a sensitizing strategy to overcome 5-fluorouracil (5-FU) therapeutic resistance is needed in colon cancer. Recent studies highlight the oncogenic role of ubiquitin specific peptidase 8 (USP8) in many cancers. In line with these efforts, this work investigated the therapeutic potential of targeting USP8 in colon cancer. METHODS: Immunohistochemistry was performed to determine USP8 expression level in colon cancer tissues and their adjacent normal tissues. Gain-of-function analysis via plasmid overexpression and loss-of-function analysis via siRNA knockdown were applied on cellular assays. The combinatory effects of USP8 inhibitor and cisplatin were determined using a colon xenograft mouse model. Immunoblotting was performed to investigate the molecular mechanism of USP8 inhibition in colon cancer cells. RESULTS: Compared to normal counterparts, we showed that USP8 protein level was significantly higher in colon cancer tissues and cells. In addition, USP8 expression was not affected by prolonged exposure of colon cancer cells to 5-FU. USP8 was important for colon cancer cell growth and survival but not migration as assessed by loss-of-function and gain-of-function approaches. Pharmacological inhibition of USP8 using USP8 inhibitor is active against both sensitive and 5-FU-resistant colon cancer cells. Of note, USP8 inhibitor significantly inhibited colon cancer formation and growth, and augmented in vivo efficacy of 5-FU without causing toxicity in mice. Mechanistic studies showed that USP8 inhibitor acted on colon cancer cells through suppressing EGFR and EGFR-mediated signalling pathways. CONCLUSIONS: Our work is the first to reveal the essential role of USP8 in colon cancer via EGFR oncogenic signalling pathways. Our findings provide a proof-of-concept that USP8 inhibitors are promising candidates to overcome 5-FU resistance in colon cancer.

Dual targeting of Mcl-1 and Bcl-2 to overcome chemoresistance in cervical and colon cancer.

After an initial positive response to chemotherapy, cancer patients often become resistant and experience relapse. Our previous research identified eukaryotic translation initiation factor 4E (eIF4E) as a crucial target to overcome chemoresistance. In this study, we delved further into the role and therapeutic potential of myeloid cell leukemia 1 (Mcl-1), an eIF4E-mediated target, in chemoresistance. We showed that the levels of phosphor and total eIF4E, as well as Mcl-1, were elevated in chemoresistant cervical but not colon cancer cells. Mcl-1 inhibitor S64315 decreased Mcl-1 levels in chemoresistant cancer cells, regardless of Mcl-1 upregulation, decreased viability in chemoresistant cancer cells and acted synergistically with chemotherapy drugs. The combined inhibition of Mcl-1 and B-cell lymphoma 2 (Bcl-2), employing both genetic and pharmacological approaches, led to a markedly more substantial decrease in viability compared with the inhibition of either target individually. The combination of S64315 and Bcl-2 inhibitors reduced tumor growth in chemoresistant cervical and colon cancer models without causing general toxicity in mice. This combination also prolonged overall survival compared with using S64315 or venetoclax alone. Our research highlights the therapeutic potential of inhibiting Mcl-1 and Bcl-2 simultaneously in chemoresistant cancers and provides a rationale for initiating clinical trials to investigate the combination of S64315 and venetoclax for the treatment of advanced colon and cervical cancer.

Characterization of Circular RNA Expression Profiles in Colon Specimens of Patients with Slow Transit Constipation.

Background: Slow transit constipation (STC) is a clinical syndrome characterized by a decreased urge to defecate and delayed colonic transit. Circular RNAs (circRNAs) are a recently discovered class of regulatory RNAs that have emerged as critical biomarkers and regulators of various diseases. However, the expression profiles and mechanisms underlying circRNA regulation in human STC tissues have not been explored. Methods: High-throughput RNA sequencing technology was used to compare the differences in circRNA expression profiles in colon samples taken from patients with STC or controls. Bioinformatics analyses were performed on the host genes of the differentially expressed circRNAs (DE-circRNAs), a competing endogenous RNA network was constructed, and the expression levels of some DE-circRNAs were verified using quantitative real-time polymerase chain reactions (qRT-PCR). Results: There were 190 DE-circRNAs identified in the STC group. Bioinformatics analysis predicted that the DE-circRNAs were enriched in the relaxation of smooth muscle, actin binding, actin cytoskeleton organization, dilated cardiomyopathy, and cardiac muscle contraction. These results suggest that muscle diseases may be related to the pathogenesis of STC. The expression levels of the 12 most differentially expressed circRNAs were verified using qRT-PCR. In addition, circRNA-microRNA-mRNA regulatory networks were constructed using the 8 most significant circRNAs. Some mRNAs predicted to be closely related to smooth muscle function were found in these networks. Conclusions: This study provides a helpful blueprint for researchers to select candidate circRNAs for further study of the pathogenesis of STC and screen potential biomarkers or targets for use in the diagnosis and treatment of STC.

Comparison of the clinical outcomes of skin bridge loop ileostomy and traditional loop ileostomy in patients with low rectal cancer.

To compare the clinical results of patients with low rectal cancer who underwent skin bridge loop ileostomy and traditional loop ileostomy, and provide clinical evidence for choosing a better ostomy method. We retrospectively collected data of 118 patients with rectal cancer who underwent low anterior resection and loop ileostomy. To investigate the patients characteristics, postoperative stoma-related complications and the frequency of exchanged ostomy bags. The differences of these indicators between the two groups of patients who underwent skin bridge loop ileostomy and traditional loop ileostomy were compared. The Visual Analog Scale (VAS) score of the skin bridge loop ileostomy group was lower than that of the traditional ileostomy loop group (P < 0.05). The skin bridge group had a lower Discoloration, Erosion, Tissue overgrowth (DET) score and incidence of mucocutaneous separation than the traditional group at the 1st and 2nd weeks after operation (P < 0.05). The average number of weekly exchanged ostomy bags was significantly less in the skin bridge group than in the traditional group within 4 weeks after surgery (P < 0.05). Our experience demonstrates that the skin bridge loop ileostomy may significantly reduce early postoperative stoma-related complications, the frequency of exchanged ostomy bags and patients' medical costs after discharge.

SNHG20/miR-140-5p/NDRG3 axis contributes to 5-fluorouracil resistance in gastric cancer.

5-fluorouracil (5-FU)-based chemotherapy is the first line treatment for advanced gastric cancer. However, the effectiveness of 5-FU is limited by drug resistance. The N-myc downstream-regulated gene, family member 3 (NDRG3) is a member of the NDRG family and has been implicated in numerous types of cancer. However, the role of NDRG3 in gastric cancer remains unclear. In the present study, NDRG3 mRNA expression in gastric cancer and adjacent normal tissues was analyzed using the Gene Expression Profiling Interactive Analysis web tool. NDRG3 expression was silenced using short hairpin RNAs to examine the effect of NDRG3 on the growth of gastric cancer cells. Potential regulators of NDRG3 were identified using the TargetScan and MicroRNA tools and verified by a luciferase assay and reverse transcription-quantitative PCR analysis. The current study demonstrated that NDRG3 was upregulated in gastric cancer specimens and promoted cell proliferation in gastric cancer cell lines. Furthermore, the present study revealed that the small nucleolar RNA host gene 20 (SNHG20)/microRNA (miR)-140-5p signaling pathway may regulate the expression of NDRG3. SNHG20 was revealed to be involved in mediating resistance to 5-FU in gastric cancer cell lines via NDRG3. In conclusion, the results of the present study suggest that the SNHG20/miR-140-5p/NDRG3 axis may be involved in mediating resistance to 5-FU in gastric cancer.

Inhibition of cyclin-dependent kinases by AT7519 is effective to overcome chemoresistance in colon and cervical cancer.

Cyclin-dependent kinases (CDK), a family of heterodimeric kinases that play central roles in regulation of cell cycle progression and transcription, have garnered attention in recent years because their aberrant activity has been reported in a wide variety of human cancers. AT7519 is a multitargeted CDK inhibitor that is currently in clinical trials for the treatment of refractory blood cancers. In this work, we are the first to provide preclinical evidence that AT7519 is an attractive candidate to overcome chemoresistance in colon and cervical cancer. We show that AT7519 is effective in targeting a panel of colon and cervical cancer cell lines, with IC50 range from 0.1 to 1 µM. Importantly, AT7519 at similar IC50 range inhibits growth and induces apoptosis of paclitaxel-resistant cervical cancer cells and 5-FU-resistant colon cancer cells. AT7519 at sublethal concentration remarkably augments the inhibitory effects of 5-FU and paclitaxel in colon and cervical cancer cells. Mechanistically, we show that AT7519 suppresses phosphorylation of CDK1, CDK2 and RNA polymerase II in chemoresistant colon and cervical cancer cells. We further confirm the efficacy of AT7519 and its mechanisms of the action using two independent chemoresistant xenograft mouse models: 5-FU-resistant colony cancer xenograft and paclitaxel-resistant cervical cancer xenograft. Our findings support the clinical trials of AT7519 for cancer treatment. Our work also demonstrates the therapeutic value of inhibiting CDK in chemoresistant cancers.

MMP-1/TIMP-1 expressions in rectal submucosa of females with obstructed defecation syndrome associated with internal rectal prolapse.

OBJECTIVE: To explore the MMP-1/TIMP-1 expressions in rectal submucosa of females with obstructed defecation syndrome (ODS) associated with internal rectal prolapse (IRP). METHODS: Fifty-six female patients with ODS associated with IRP were enrolled as Case group, and 43 female hemorrhoids of stages III-IV without constipation and IRP were enrolled as Control group. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry were performed to test the expressions of MMP-1/TIMP-1 in the rectal submucosa. Western blotting was used to examine protein expressions of MMP-1/TIMP-1 and pro-inflammatory cytokines (IL-6 and TNF-α) in the rectal submucosa. EVG staining was conducted to detect collagen and elastic fibers in rectal submucosa. RESULTS: The increased expression of MMP-1 was negatively linked to the decreased TIMP-1 level in the rectal submucosa of patients with ODS associated with IRP. Besides, the expressions of IL-6 and TNF-α were increased in the Case group as compared with the Control group. Additionally, ODS severity and the pro-inflammatory cytokines was positively linked to MMP-1, but negatively related to TIMP-1 in Case group. EVG staining showed that the area ratios of collagen and elastic fibers were lower in Case group than Control group. Through Pearson's correlation analysis, the area ratios of collagen and elastic fibers were positively associated with MMP-1 expression, but negatively correlated with TIMP-1 expression in rectal submucosa of patients with ODS associated with IRP. CONCLUSION: Elevated MMP-1 and reduced TIMP-1 were found in ODS associated with IRP, which was related to the ODS severity, inflammation and contents of collagen and elastic fibers.

Migration of a foreign body to the rectum: A case report and literature review.

RATIONALE: Rectal foreign bodies are not an uncommon finding in outpatient departments globally. Most such objects are inserted through the anus. Occasionally, a foreign body may be ingested and may successfully pass through the entire gastrointestinal tract and be held up in the rectum. In extremely rare cases, foreign bodies in adjacent tissues or organs can penetrate the rectal wall and enter the rectal lumen. We report a rare case that the IUCD had migrated and was embedded in the rectal wall. A part of the IUCD was loosened and deformed into a metallic wire that protruded through the anus. PATIENT CONCERNS: A 45-year-old woman presented with complaints of a metallic wire protruding through her anus when she used the washroom. The wire would become longer when she manually pulled it; however, this process was associated with pain in the lower abdomen, and she therefore stopped manipulating it. DIAGNOSES: A rectal foreign body secondary to intrauterine contraceptive device (IUCD) migration and rectal perforation, as well as a pelvic cyst. INTERVENTIONS: Under general anesthesia, she underwent laparoscopic removal of the rectal foreign body, pelvic adhesiolysis, pelvic cyst resection, and ileostomy combined with colonoscopy. OUTCOMES: Her postoperative recovery was uneventful. LESSONS: Foreign bodies in adjacent tissues or organs can penetrate the rectal wall and enter the rectal lumen. Regular follow-up after IUCD insertion is very important. We report this rare case that would increase awareness among clinicians regarding the differential diagnosis and treatment in such cases.

Inhibition of eukaryotic translation initiation factor 4E is effective against chemo-resistance in colon and cervical cancer.

Although cancer patients initially respond well to chemotherapy, they eventually develop resistance and relapse. In this work, we demonstrate that eIF4E-targeting therapy is a potential sensitizing strategy for overcoming chemoresistance and progression in cancer. We show that ribavirin, an anti-viral drug and pharmacological eIF4E inhibitor, effectively inhibits proliferation and decreases viability of paclitaxel-resistant cervical cancer and 5-FU-resistant colon cancer cells while is less toxic to human fibroblast cells. Importantly, oral administration of ribavirin significantly inhibits paclitaxel-resistant colon and 5-FU-resistant cervical cancer growth in xenograft mouse cancer model without causing significant toxicity in mice. Consistently, combination of ribavirin with paclitaxel or 5-FU sensitizes colon and cervical cancer cells to chemotherapeutic agents treatment in vitro and in vivo. We further confirm that the mechanism of the action of ribavirin in chemoresistant cancer cells is through suppressing eIF4E function. In addition, specific eIF4E knockdown via two independent siRNA mimics the effects of ribavirin in chemoresistant colon and cervical cancer cells. Cell cycle analysis indicate that ribavirin enhances the anti-proliferative effect of 5-FU by additionally arresting cells at G2/M phase via increasing cyclin B1, p-histone H3(Ser10) and Mad2 levels. Our work demonstrates that eIF4E inhibition using inhibitor or siRNA, either as single agent or in combination, could sensitize chemoresistant cancer cells to paclitaxel or 5-FU treatment and thereby improving the efficacy of chemodrug. Our findings demonstrate the therapeutic value of inhibiting eIF4E, particularly in chemoresistant cancers. Our findings also suggest ribavirin as a promising sensitizing drug for cancer treatment.

Role of miR-22 in intestinal mucosa tissues and peripheral blood CD4+ T cells of inflammatory bowel disease.

OBJECTIVE: miR-22 is known to be involved in the pathogenesis of several autoimmune diseases, but it remains unclear whether miR-22 is associated with inflammatory intestinal disease (IBD). METHODS: The patients with ulcerative colitis (UC) and Crohn's disease (CD) were enrolled in this study. After the CD4+ T cells from healthy controls and active IBD patients were isolated and then transfected with miR-22 mimics/inhibitors, Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to measure expressions of miR-22, HDAC4, specific transcription factors in intestinal mucosa tissue and CD4+ T cells, while enzyme-linked immuno sorbent assay (ELISA) to detect expressions of inflammatory cytokines in PB. Antisense miR-22 was administered into mice during trinitrobenzene sulphoni cacid (TNBS)-induced colitis to determine its role in IBD. RESULTS: A significant elevation of miR-22 but an evident decrease of HDAC4 was found in CD4+ T cells in PB and intestinal mucosa tissues from IBD patients. In addition, there was a great reduction in HDAC4 and a dramatic enhancement in Th17 cell specific transcription factor (RORC) and inflammatory cytokines (IL-17A, IL-6 and TNF-α) after overexpression miR-22, which was opposite to the effect of inhibition of miR-22. Furthermore, administration of antisense miR-22 in TNBS-induced mouse colitis model significantly decreased numbers of interleukin (IL)-17A+ CD4+ T cells and the expressions of IL-17A, RORC, IL-6 and TNF-α. CONCLUSION: MiR-22 was up-regulated in CD4+ T cells in PB and intestinal mucosa tissues of IBD patients, which could promote Th17 cell differentiation via targeting HDAC4 to be involved in IBD progression.

SERPINA3 Silencing Inhibits the Migration, Invasion, and Liver Metastasis of Colon Cancer Cells.

OBJECTIVE: To investigate the impact of SERPINA3 on the migration, invasion, and liver metastasis of colon cancer cells. METHODS: Immunohistochemical staining was conducted to determine SERPINA3 expression in the cancer and adjacent normal tissues of 131 patients suffering from colon cancer. In vitro experiment, colon cancer cells with low (HT-29P), intermediate (KM-12C), and high (HT-29LMM, KM-12L4) metastatic potential were obtained to examine SERPINA3 expression levels. Besides, quantitative real-time PCR (qRT-PCR) and Western Blot were performed to detect SERPINA3 expression in HT-29LMM and KM-12L4 cells transfected with SERPINA3 siRNA; Wound-healing and Transwell assays to measure cell migration and invasion, respectively; and ELISA to detect MMP-2 and MMP-9 levels. In vivo experiment, mice with liver metastasis of colon cancer were established to observe the effect of SERPINA3 silencing on liver metastasis. Immunohistochemical assay was applied to evaluate the expressions of Serpina3, Mmp-2, Mmp-9, and proliferating cell nuclear antigen (Pcna) in liver metastasis tissues. RESULTS: SERPINA3 in colon cancer tissues was higher than in adjacent normal tissues, which was associated with patients' clinicopathological features. Besides, SERPINA3 expression showed a rising trend in low, intermediate, and high metastatic potential colon cancer cells. After KM-12L4 and HT-29LMM cells transfected with SERPINA3 siRNA, the migration and invasive ability of cells, as well as the expression levels of MMP-2 and MMP-9 were all decreased. Moreover, SERPINA3 siRNA could not only reduce live metastasis of mice, but also down-regulate the expression of Mmp-2 and Mmp-9 in liver metastasis tissues. CONCLUSION: SERPINA3 silencing could inhibit the migration, invasion, and liver metastasis of colon cancer cells.