Unveiling YWHAH: A potential therapeutic target for overcoming CD8+ T cell exhaustion in colorectal cancer.

Colorectal cancer (CRC) is a significant global health challenge, with increasing rates of incidence and mortality. Despite advancements in immunotherapy, resistance, particularly due to T cell exhaustion, remains a major hurdle. This study explores the role of YWHAH, mediated by N4-acetylcytidine (ac4C) modification, in CRC progression and its impact on CD8+ T cell exhaustion. Analysis of five paired CRC patient tissue samples using acetylated RNA immunoprecipitation and sequencing (acRIP-seq)identified ac4C-modified mRNAs. Functional assays, including cell culture, transfection, qRT-PCR, and immune assays, investigated the influence of YWHAH expression on CRC advancement. Bioinformatics analysis of TCGA data assessed the correlation between YWHAH and immune responses, as well as checkpoint inhibitors. Flow cytometry and Immunohistochemistry validated these findings, complemented by a co-culture experiment involving CD8+ T cells and CRC cell lines (LOVO and HCT116). acRIP-seq revealed YWHAH as a potential driver of CRC progression, exhibiting ac4C modification-mediated stability and upregulation. High YWHAH levels correlated with adverse outcomes and immune evasion in CRC patients, showing strong associations with immune checkpoint proteins and modest correlations with CD8+ T cell infiltration. Co-culture experiments demonstrated YWHAH-induced CD8+ T cell exhaustion, characterized by decreased proliferation and increased exhaustion markers. NAT10-mediated ac4C modification enhanced YWHAH stability in CRC. The involvement of YWHAH in CD8 + T cell exhaustion suggests its potential as a therapeutic target and prognostic marker in CRC immunotherapy, highlighting the intricate interplay between epitranscriptomic modifications, the tumor microenvironment, and immune responses in CRC progression.

SETBP1 activation upon MDM4-enhanced ubiquitination of NR3C1 triggers dissemination of colorectal cancer cells.

Colorectal cancer (CRC) presents a growing concern globally, marked by its escalating incidence and mortality rates, thus imposing a substantial health burden. This investigation delves into the role of nuclear receptor subfamily 3 group C member 1 (NR3C1) in CRC metastasis and explores the associated mechanism. Through a comprehensive bioinformatics analysis, NR3C1 emerged as a gene with diminished expression levels in CRC. This finding was corroborated by observations of a low-expression pattern of NR3C1 in both CRC tissues and cells. Furthermore, experiments involving NR3C1 knockdown revealed an exacerbation of proliferation, migration, and invasion of CRC cells in vitro. Subsequent assessments in mouse xenograft tumor models, established by injecting human HCT116 cells either through the tail vein or at the cecum termini, demonstrated a reduction in tumor metastasis to the lung and liver, respectively, upon NR3C1 knockdown. Functionally, NR3C1 (glucocorticoid receptor) suppressed SET binding protein 1 (SETBP1) transcription by binding to its promoter region. Notably, mouse double minute 4 (MDM4) was identified as an upstream regulator of NR3C1, orchestrating its downregulation via ubiquitination-dependent proteasomal degradation. Further investigations unveiled that SETBP1 knockdown suppressed migration and invasion, and epithelial to mesenchymal transition of CRC cells, consequently impeding in vivo metastasis in murine models. Conversely, upregulation of MDM4 exacerbated the metastatic phenotype of CRC cells, a propensity mitigated upon additional upregulation of NR3C1. In summary, this study elucidates a cascade wherein MDM4-mediated ubiquitination of NR3C1 enables the transcriptional activation of SETBP1, thereby propelling the dissemination of CRC cells.

Identification of biomarkers for abdominal aortic aneurysm in Behçet's disease via mendelian randomization and integrated bioinformatics analyses.

Behçet's disease (BD) is a complex autoimmune disorder impacting several organ systems. Although the involvement of abdominal aortic aneurysm (AAA) in BD is rare, it can be associated with severe consequences. In the present study, we identified diagnostic biomarkers in patients with BD having AAA. Mendelian randomization (MR) analysis was initially used to explore the potential causal association between BD and AAA. The Limma package, WGCNA, PPI and machine learning algorithms were employed to identify potential diagnostic genes. A receiver operating characteristic curve (ROC) for the nomogram was constructed to ascertain the diagnostic value of AAA in patients with BD. Finally, immune cell infiltration analyses and single-sample gene set enrichment analysis (ssGSEA) were conducted. The MR analysis indicated a suggestive association between BD and the risk of AAA (odds ratio [OR]: 1.0384, 95% confidence interval [CI]: 1.0081-1.0696, p = 0.0126). Three hub genes (CD247, CD2 and CCR7) were identified using the integrated bioinformatics analyses, which were subsequently utilised to construct a nomogram (area under the curve [AUC]: 0.982, 95% CI: 0.944-1.000). Finally, the immune cell infiltration assay revealed that dysregulation immune cells were positively correlated with the three hub genes. Our MR analyses revealed a higher susceptibility of patients with BD to AAA. We used a systematic approach to identify three potential hub genes (CD247, CD2 and CCR7) and developed a nomogram to assist in the diagnosis of AAA among patients with BD. In addition, immune cell infiltration analysis indicated the dysregulation in immune cell proportions.

Activation of M2 macrophage autophagy by rapamycin increases the radiosensitivity of colorectal cancer xenografts.

BACKGROUND: Tumor-associated macrophages (TAMs) are intimately involved in cancer radiochemotherapy resistance. However, the mechanism by which macrophages affect radiosensitivity through autophagy remains unclear. The purpose of our study was to investigate how activating autophagy in type-II macrophages (M2) by using rapamycin (RAP) would affect the radiosensitivity of colorectal cancer (CRC) xenografts. MATERIALS AND METHODS: A nude mouse CRC model was established by injecting LoVo CRC cells. After tumor formation, supernatant from M2 cells (autophagy-unactivated), autophagy-activated M2 cells, or autophagy-downregulated M2 cells was injected peritumorally. All tumor-bearing mice were irradiated with 8-Gy X-rays twice, and the radiosensitivity of CRC xenografts was analyzed in each group. RESULTS: The mass, volume, and microvessel density (MVD) of tumors in the autophagy-unactivated M2 group significantly increased; however, supernatant from M2 cells that were autophagy-activated by rapamycin significantly decreased tumor weight, volume, and MVD compared with negative control. Combining bafilomycin A1 (BAF-A1) with RAP treatment restored the ability of the M2 supernatant to increase tumor mass, volume, and MVD. Immunohistochemical and Western blot results showed that compared with the negative control group, supernatant from M2 cells that were not activated by autophagy downregulated the expression of Livin and Survivin in tumor tissues; activation of M2 autophagy further downregulated the protein levels. CONCLUSIONS: Therefore, autophagy-activated M2 supernatant can downregulate the expression of the antiapoptotic genes Livin and Survivin in CRC xenografts, improving the radiosensitivity of CRC by inducing apoptosis in combination with radiotherapy and inhibiting the growth of transplanted tumors.

Development and validation of machine learning models and nomograms for predicting the surgical difficulty of laparoscopic resection in rectal cancer.

BACKGROUND: The objective of this study is to develop and validate a machine learning (ML) prediction model for the assessment of laparoscopic total mesorectal excision (LaTME) surgery difficulty, as well as to identify independent risk factors that influence surgical difficulty. Establishing a nomogram aims to assist clinical practitioners in formulating more effective surgical plans before the procedure. METHODS: This study included 186 patients with rectal cancer who underwent LaTME from January 2018 to December 2020. They were divided into a training cohort (n = 131) versus a validation cohort (n = 55). The difficulty of LaTME was defined based on Escal's et al. scoring criteria with modifications. We utilized Lasso regression to screen the preoperative clinical characteristic variables and intraoperative information most relevant to surgical difficulty for the development and validation of four ML models: logistic regression (LR), support vector machine (SVM), random forest (RF), and decision tree (DT). The performance of the model was assessed based on the area under the receiver operating characteristic curve(AUC), sensitivity, specificity, and accuracy. Logistic regression-based column-line plots were created to visualize the predictive model. Consistency statistics (C-statistic) and calibration curves were used to discriminate and calibrate the nomogram, respectively. RESULTS: In the validation cohort, all four ML models demonstrate good performance: SVM AUC = 0.987, RF AUC = 0.953, LR AUC = 0.950, and DT AUC = 0.904. To enhance visual evaluation, a logistic regression-based nomogram has been established. Predictive factors included in the nomogram are body mass index (BMI), distance between the tumor to the dentate line ≤ 10 cm, radiodensity of visceral adipose tissue (VAT), area of subcutaneous adipose tissue (SAT), tumor diameter >3 cm, and comorbid hypertension. CONCLUSION: In this study, four ML models based on intraoperative and preoperative risk factors and a nomogram based on logistic regression may be of help to surgeons in evaluating the surgical difficulty before operation and adopting appropriate responses and surgical protocols.

Tumor microenvironment reprogramming combined with immunogenic enhancement by nanoemulsions potentiates immunotherapy.

The combination of immune checkpoint inhibitors and immunogenic cell death (ICD) inducers has become a promising strategy for the treatment of various cancers. However, its efficacy remains unmet because of the dense stroma and defective vasculatures in the tumor microenvironment (TME) that restricts the intratumoral infiltration of cytotoxic T lymphocytes (CTLs). Herein, cancer-associated fibroblasts (CAFs)-targeted nanoemulsions are tailored to combine the ICD induction and the TME reprogramming to sensitize checkpoint blockade immunotherapy. Melittin, as an ICD inducer and an antifibrotic agent, is efficiently encapsulated into the nanoemulsion accompanied by a nitric oxide donor to improve its bioavailability and tumor targeting. The nanoemulsions exhibited dual functionality by directly inducing direct cancer cell death and enhancing the tumoral immunogenicity, while also synergistically reprogramming the TME through reversing the activated CAFs, decreasing collagen deposition and restoring tumor vessels. Consequently, these nanemulsions successfully facilitated the CTLs infiltration and suppressing the recruitment of immunosuppressive cells. A combination of AE-MGNPs and anti-CTLA-4 antibody greatly elicited a striking level of antitumor T-cell response to suppress tumor growth in CAFs-rich colorectal tumor models. Our work emphasized the integration of the ICD induction with simultaneous modulation of the TME to enhance the sensitivity of patients to checkpoint blockade immunotherapy.

CircFNTA promotes tumorigenesis and progression of gastric cancer via miR-604/miR-647/SCN8A axis.

Gastric cancer (GC) is a major contributor to cancer-related deaths and is characterized by high heterogeneity in epidemiology and histopathology worldwide. Increasing evidence indicates that circular RNAs (circRNAs) play multifaceted roles in cellular processes in human cancers. Here, we demonstrated that circFNTA high expression increases the proliferation, metastasis, and epithelial-mesenchymal transition process and tumorigenicity of GC cells. First, we found that circFNTA was upregulated in GC cells and tissues, and the high circFNTA levels were positively associated with the poor prognosis in GC patients. Using luciferase reporter and RNA-pull down assays, we elucidated that circFNTA sponged two microRNAs, miR-604 and miR-647. In addition, the proliferation and metastatic ability of GC cell reduction caused by silencing circFNTA was hindered by inhibitors of miR-604 and miR-647. Moreover, SCN8A was predicted by miRDB as a common target gene of miR-604 and miR-647, which was then verified by the luciferase reporter assay. Knockdown of circFNTA causes messenger RNA and protein levels in SCN8A to be downregulated in GC cells. However, this effect was overturned by cotransfection miR-604 and miR-647. Also, we identified that SCN8A was downregulated in GC tissues, which was positively correlated with circFNTA expression. In rescue experiments, the attenuated cell proliferation and metastatic ability caused by circFNTA knockdown was reversed by miR-604 and miR-647 inhibitors and SCN8A overexpression. Collectively, our findings suggest an oncogenic role of circFNTA in GC progression and elucidate that circFNTA exerts its function by modulating the miR-604/miR-647/SCN8A axis.

DNMT1-mediated NR3C1 DNA methylation enables transcription activation of connexin40 and augments angiogenesis during colorectal cancer progression.

Colorectal cancer (CRC) continues to be a major contributor to cancer-related mortality. Connexin 40 (CX40) is one of the major gap junction proteins with the capacity in regulating cell-to-cell communication and angiogenesis. This study investigates its role in angiogenesis in CRC and explores the regulatory mechanism. Aberrant high CX40 expression was detected in tumor tissues, which was associated with a poor prognosis in CRC patients. Elevated CX40 expression was detected in CRC cell lines as well. Conditioned medium of SW620 and HT29 cell lines was used to induce angiogenesis of human umbilical vein endothelial cells (HUVECs). CX40 knockdown in CRC cells reduced angiogenesis and mobility of HUVECs and blocked CRC cell proliferation, mobility, and survival. Following bioinformatics predictions, we validated by chromatin immunoprecipitation and luciferase assays that nuclear receptor subfamily 3 group C member 1 (NR3C1), which was poorly expressed in CRC samples, suppressed CX40 transcription. The poor NR3C1 expression was attributive to DNA hypermethylation induced by DNA methyltransferase 1 (DNMT1). Restoration of NR3C1 suppressed the pro-angiogenic effect, proliferation and survival, and tumorigenic activity of CRC cells, which were, however, rescued by CX40 upregulation. Collectively, this study demonstrates that transcription activation of CX40 upon DNMT1-mediated NR3C1 DNA methylation potentiates angiogenesis in CRC.

Decreased KLF3 Expression via miR-660-5p Targeting Suppresses Gastric Cancer Cell Progression.

OBJECTIVE: Gastric cancer (GC) is one of the most frequent cancers in the world. Recent studies have suggested that microRNAs (miRNAs/miRs) may act as novel therapeutic regimens for GC. This study revealed that miR-660-5p regulated the proliferation, migration, invasion, and apoptosis of GC cells via controlling the level of Krüppel-like factor 3 (KLF3). METHODS: The level of miR-660-5p was measured in clinical GC tissues. Then, the miRNA targeting relationship between miR-660-5p and KLF3 was explored in vitro. GC cell lines, including HGC-27, SNU-1, HS-746T, NCI-N87, and human gastric epithelial GES-1 cells, were used. The impact of miR-660-5p on cell proliferation, colony formation, invasion, migration, and apoptosis were determined by knocking down KLF3. RESULTS: It was demonstrated that the KLF3 expressions were significantly increased in GC tissues and cell lines compared to normal tissues or cells, and GC cell development was suppressed following KLF3 knockdown. Moreover, it was also revealed that miR-660-5p expression was significantly decreased in GC cells, and miR-660-5p acted as the direct regulator of KLF3. CONCLUSIONS: This study firstly reported the miR-660-5p/KLF3 interaction in GC, and the results provided a potential promising therapeutic target for GC.

METTL3 regulates N6-methyladenosine modification of ANGPTL3 mRNA and potentiates malignant progression of stomach adenocarcinoma.

BACKGROUND: N6-methyladenosine (m6A) is associated with mammalian mRNA biogenesis, decay, translation and metabolism, and also contributes greatly to gastrointestinal tumor formation and development. Therefore, the specific mechanisms and signaling pathways mediated by methyltransferase-like 3 (METTL3), which catalyzes the formation of m6A chemical labeling in stomach adenocarcinoma (STAD), are still worth exploring. METHODS: Quantitative real-time PCR (qRT-PCR) was constructed to detect the expression of METTL3 in gastric cancer cell lines and patient tissues. The biological function of METTL3 was investigated in vitro/in vivo by Cell Counting Kit-8, colony formation assay, Transwell assay and nude mouse tumorigenesis assay. Based on the LinkedOmics database, the genes co-expressed with METTL3 in the TCGA STAD cohort were analyzed to clarify the downstream targets of METTL3. Methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) and RNA stability analysis were employed to explore the mechanism of METTL3 in gastric cancer progression. RESULTS: We analyzed TCGA data and found that METTL3 was frequently elevated in STAD, and demonstrated that METTL3 was present at high levels in clinical STAD tissues and cells. High METTL3 expression was more likely to have advanced TNM tumors and distant metastasis. On the other hand, METTL3 silencing effectively impeded the higher oncogenic capacity of AGS and HGC27 cells in vivo and in vitro, as reflected by slowed cell growth and diminished migration and invasion capacities. Continued mining of the TCGA dataset identified the co-expression of angiopoietin-like 3 (ANGPTL3) and METTL3 in STAD. Lower level of ANGPTL3 was related to increased level of METTL3 in STAD samples and shorter survival times in STAD patients. ANGPTL3 enrichment limited the growth and metastasis of STAD cells. Besides, ANGPTL3 mRNA levels could be decreased by METTL3-dominated m6A modifications, a result derived from a combination of MeRIP-qPCR and RNA half-life experiments. Importantly, the inhibitory effect of METTL3 silencing on cancer could be reversed to some extent by ANGPTL3 inhibition. CONCLUSIONS: Overall, our findings suggested that METTL3 functioned an oncogenic role in STAD by reducing ANGPTL3 expression in an m6A-dependent manner. The discovery of the METTL3-ANGPTL3 axis and its effect on STAD tumor growth will contribute to further studies on the mechanisms of gastric adenocarcinoma development.

Laparoscopic proximal gastrectomy with right-sided overlap and single-flap valvuloplasty (ROSF): a case-series study.

BACKGROUND: There is no standard reconstruction method following proximal gastrectomy, of which gastroesophageal reflux and anastomotic complications are of great concern. Though several techniques have been devised to overcome these postoperative complications, such as double tract reconstruction, double-flap technique and side overlap fundoplication by Yamashita, none of them is considered a perfect solution. Herein, we designed a novel method of esophagogastrostomy after laparoscopic proximal gastrectomy (LPG), named right-sided overlap and single-flap valvuloplasty (ROSF). METHODS: Between March 2021 and December 2021, 20 consecutive patients underwent LPG-ROSF at Department of Gastrointestinal Surgery, Second Affiliated Hospital of Soochow University. Surgical outcomes and postoperative complications were recorded. All patients were followed-up until December 2022. Endoscopy and assessment of gastrointestinal symptoms were performed 1 year after surgery. Nutrition-related parameters including total body weight, hemoglobin, lymphocyte count, serum total protein, serum albumin and serum prealbumin were evaluated 1 year after surgery and compared with those before surgery. RESULTS: The mean surgery time and anastomosis time was 285.3 ± 71.3 and 61.3 ± 11.2 min respectively. None of the patients had gastrointestinal early postoperative complications. Symptomatic reflux was observed in one patient (5%) while reflux esophagitis (Los Angeles Grade A) was observed in another patient (5%). Four patients (20%) had mild dysphagia (Visick score = II) but none of them had anastomotic stenosis. There were no significant changes in nutritional status postoperatively. CONCLUSIONS: ROSF can be safely performed after LPG and has satisfactory outcomes in preventing reflux and stenosis, and maintaining nutritional status. This technique requires further validation.

Novel Method for Detection of PIK3CA Mutations in Circulating Tumor DNA of Patients with Colorectal Cancer.

The PIK3CA mutation is considered a potential target for treatment of colorectal cancer. We evaluated a PIK3CA mutation assay on plasma cell-free DNA (cfDNA) using a newly developed PCR with restriction digestion integrated and followed by Sanger's sequencing. We analyzed PIK3CA mutation in plasma with our newly developed assays and in matching tumor tissues by routine methods. We detected the PIK3CA gene mutation status by both methods in samples from 40 colorectal cancer patients. Three H1047R mutations of PIK3CA gene were detected in the cfDNA of the 40 patients by restriction digestion PCR. Neither E545K nor H1047R mutations were detected in the cfDNA by routine PCR/sequencing. The PIK3CA H1047R and E545K mutations in cfDNA can be sensitively detected with our newly developed assays. The colorectal cancer has been used as a clinical example in testing our new assays, which indicates that the new assays may have wider applications in detecting mutations in precision oncology. Trial registration: Current Controlled Trials ChiCTR-DDT-12002848, 8 October 2012.

FOXC2-induced circCASK aggravates colorectal cancer progression by upregulating SIX1 expression.

Colorectal cancer (CRC) ranks as the most common gastrointestinal solid carcinoma globally. Substantial evidence has established a pivotal role for circular RNAs (circRNAs) in CRC progression. In this study, differentially expressed circRNAs were analyzed based on a public dataset (GSE126094) and elevated expression of circCASK (hsa_circ_0001917) was validated in CRC. Moreover, increased circCASK was also confirmed in CRC patients. Functionally, circCASK knockdown led to a significant decrease in CRC cell growth and attenuated cell migration and invasion. Similarly, circCASK knockdown markedly attenuated tumor growth in vivo. Mechanistically, circCASK sponged miR-1271-5p and enhanced sine oculis homeobox homolog 1 (SIX1) expression. More importantly, both SIX1 overexpression and miR-1271-5p knockdown could reverse the cellular behavior inhibition induced by circCASK knockdown. Furthermore, SIX1 was most strongly and positively linked with Wnt/ß-catenin signaling pathways, circCASK triggered Wnt/ß-catenin signaling through the miR-1271-5p/SIX1 axis, and FOXC2 transcriptionally induced circCASK expression. In conclusion, circCASK induced by FOXC2 accelerated CRC progression through the miR-1271-5p/SIX1 axis, thus providing an interesting insight into CRC tumorigenesis.

GOLM1 facilitates human colorectal cancer progression and metastasis via activating the AKT/GSK3ß/EMT axis.

GOLM1 (Golgi membrane protein 1), a key tumor progression- and metastasis-related marker, is highly expressed in a variety of epithelium-derived human cancers. However, its expression and functions in human colorectal cancer (CRC) have been rarely explored. The present study verified the high expression of GOLM1 within CRC tissues and cell lines. GOLM1 was positively correlated with vascular invasion, TNM stage, and lymph node metastasis among CRC cases. In vitro experiments showed that GOLM1 downregulation inhibited the growth, migration, and invasion of Caco-2 and HCT116 cells, while the overexpression of GOLM1 facilitated the growth, migration, and invasion of SW480 cells. In vivo experiments revealed that the knockdown of GOLM1 reduced the growth of nude mouse xenografts and lung metastasis of HCT116 cells. Furthermore, GOLM1 was found to be a motivator for the epithelial-mesenchymal transition (EMT) phenotype and the AKT/GSK3ß pathway in CRC cells. Finally, MK2206, an AKT inhibitor, could markedly reverse GOLM1-elicited proliferation, migration, invasion, and EMT phenotype by inhibiting the AKT/GSK3ß pathway. Collectively, our data indicate that GOLM1 facilitates human CRC progression and metastasis via activating the AKT/GSK3ß/EMT axis. Most importantly, our study makes substantial support for the clinical translation of GOLM1 in CRC target therapy.

Multi-omics Analysis of the Role of PHGDH in Colon Cancer.

Objectives: Serine metabolism is essential for tumor cells. Endogenous serine arises from de novo synthesis pathways. As the rate-limiting enzyme of this pathway, PHGDH is highly expressed in a variety of tumors including colon cancer. Therefore, targeted inhibition of PHGDH is an important strategy for anti-tumor therapy research. However, the specific gene expression and metabolic pathways regulated by PHGDH in colon cancer are still unclear. Our study was aimed to clarified the role of PHGDH in serine metabolism in colon cancer to provide new knowledge for in-depth understanding of serine metabolism and PHGDH function in colon cancer. Methods: In this study, we analyzed the gene expression and metabolic remodeling process of colon cancer cells (SW620) after targeted inhibition of PHGDH by gene transcriptomics and metabolomics. LC-MS analysis was performed in 293T cells to PHGDH gene transcription and protein post-translational modification under depriving exogenous serine. Results: We found that amino acid transporters, amino acid metabolism, lipid synthesis related pathways compensation and other processes are involved in the response process after PHGDH inhibition. And ATF4 mediated the transcriptional expression of PHGDH under exogenous serine deficiency conditions. While LC-MS analysis of post-translational modification revealed that PHGDH produced changes in acetylation sites after serine deprivation that the K289 site was lost, and a new acetylation site K21was produced. Conclusion: Our study performed transcriptomic and metabolomic analysis by inhibiting PHGDH, thus clarifying the role of PHGDH in gene transcription and metabolism in colon cancer cells. The mechanism of high PHGDH expression in colon cancer cells and the acetylation modification that occurs in PHGDH protein were also clarified by serine deprivation. In our study, the role of PHGDH in serine metabolism in colon cancer was clarified by multi-omics analysis to provide new knowledge for in-depth understanding of serine metabolism and PHGDH function in colon cancer.

Contribution of microRNA-30d to the prevention of the thyroid cancer occurrence and progression: mechanism and implications.

Thyroid cancer is a major endocrine tumor and represents an emerging health problem worldwide. MicroRNAs (miRNAs) have been addressed to participate in the pathogenesis and progression of thyroid cancer. However, it remains largely unknown what functions miR-30d may exert on thyroid cancer. This study, herein, aimed to identify the functional significance and machinery of miR-30d in the progression of thyroid cancer. MiR-30b presented aberrant low expression and ubiquitin-specific protease 22 (USP22) exhibited aberrant high expression in thyroid cancer tissues and cells. The current study proposed the possible machinery that miR-30d could target and negatively regulate USP22. Additionally, USP22 could enhance the stability of SIRT1 by inducing deubiquitination which consequently contributed to FOXO3a deacetylation-induced PUMA repression. Responding to the gain- or loss-of-function of miR-30d and/or USP22, behaviors of thyroid cancer cells were altered. Accordingly, miR-30d inhibited proliferation and promoted apoptosis of thyroid cancer cells by suppressing USP22 through SIRT1/FOXO3a/PUMA axis. The effects of miR-30d and USP22-mediated SIRT1/FOXO3a/PUMA axis on thyroid tumorigenesis were finally validated in murine models. We ultimately confirmed the anti-proliferative and pro-apoptotic effect of miR-30d via suppressing USP22 through in vivo findings. Conclusively, our findings highlight that the occurrence and progression of thyroid cancer can be suppressed by miR-30d-mediated inhibition of USP22 via the SIRT1/FOXO3a/PUMA axis, which provides a attractive therapeutic target for thyroid cancer treatment.

Exosomal circ_0091741 promotes gastric cancer cell autophagy and chemoresistance via the miR-330-3p/TRIM14/Dvl2/Wnt/ß-catenin axis.

The importance of cancer cell-released exosomes in the treatment of various cancers has been well-characterized. The current study aims to examine the potential biological functions of gastric cancer (GC) cell-released exosomes delivering a novel circRNA circ_0091741 in GC and the underlying molecular mechanism. Expression of circ_0091741 was examined in the GC cells, (OXA)-resistant HGC-27 (HGC-27/OXA) cells, and isolated exosomes, after which its downstream miRNA was analyzed. The role and mechanism of the circ_0091741 transmitted by GC cells-derived exosomes in GC cell autophagy and chemoresistance were assessed using various molecular biological methods. A mouse tumor xenograft model was prepared to discern the effect of circ_0091741 on tumorigenesis in vivo. GC cells and their exosomes were characterized by upregulated circ_0091741 expression. circ_0091741 transferred by GC cell-derived exosomes induced the autophagy and OXA resistance of GC cells. circ_0091741 obstructed the binding of miR-330-3p to TRIM14 and increased the expression of TRIM14. TRIM14 could cause activation of the Wnt/ß-catenin signaling pathway by stabilizing Dvl2. By this mechanism, the autophagy and OXA resistance of GC cells were augmented. In vivo assay unfolded that orthotopic implantation of exosomal circ_0091741 overexpressed GC cells into nude mice enhanced tumorigenesis. In conclusion, our study emphasized the promotive role of exosomal circ_0091741 in autophagy and chemoresistance of GC cells, thus laying the basis for the development of novel therapeutic targets for GC treatment.

TCN1 Deficiency Inhibits the Malignancy of Colorectal Cancer Cells by Regulating the ITGB4 Pathway.

Background/Aims: This study aimed to investigate the biological function and regulatory mechanism of TCN1 in colorectal cancer (CRC). Methods: We studied the biological function of TCN1 by performing gain-of-function and loss-of-function analyses in HCT116 cell lines; examined the effects of TCN1 on the proliferation, apoptosis, and invasion of CRC cells; and determined potential molecular mechanisms using HCT116 and SW480 CRC lines and mouse xenotransplantation models. Tumor xenograft and colonization assays were performed to detect the tumorigenicity and metastatic foci of cells in vivo. Results: TCN1 knockdown attenuated CRC cell proliferation and invasion and promoted cell apoptosis. Overexpression of TCN1 yielded the opposite effects. In addition, TCN1-knockdown HCT116 cells failed to form metastatic foci in the peritoneum after intravenous injection. Molecular mechanism analyses showed that TCN1 interacted with integrin subunit ß4 (ITGB4) to positively regulate the expression of ITGB4. TCN1 knockdown promoted the degradation of ITGB4 and increased the instability of ITGB4 and filamin A. Downregulation of ITGB4 at the protein level resulted in the disassociation of the ITGB4/plectin complex, leading to cytoskeletal damage. Conclusions: TCN1 might play an oncogenic role in CRC by regulating the ITGB4 signaling pathway.

Cancer-associated fibroblast-targeted nanodrugs reshape colorectal tumor microenvironments to suppress tumor proliferation, metastasis and improve drug penetration.

Cancer-associated fibroblasts (CAFs) produce a critical tumor-promoting effect by cellular crosstalk with cancer cells and remodel the extracellular matrix (ECM) to form a protective physical barrier. The simple elimination of CAFs is not sufficient to govern the CAF-shaped aggressive tumor microenvironment (TME) because of the complexity of tumors. Herein, a CAF-targeted poly (lactic-co-glycolic acid) (PLGA) nanoemulsion is tailored to simultaneously deliver doxorubicin (DOX) and small interfering RNA (siRNA) targeting hepatocyte growth factor (HGF) for the combination of chemotherapy and gene therapy. The nanoemulsion (apt-Si/DNPs) shows a high specificity towards CAFs due to the aptamer modification and efficiently induces the apoptosis of CAFs, thus decreasing ECM deposition in the TME. Importantly, the delivered siRNA reduces the expression of the HGF in the remaining CAFs, which overcomes chemotherapy-induced upregulation of HGF mRNA and prevents the reproduction of CAFs through the autocrine HGF closed-loop. Owing to these synergetic effects, tumor proliferation, migration and invasion are prominently inhibited and tumor permeability is improved significantly. Overall, these results emphasize the potential of CAF-targeted combination treatments to inhibit tumor progression and metastasis, as well as overcome therapeutic resistance.