circSKA3 promotes colorectal cancer metastases through miR-1238 and methylation.

Colorectal cancer (CRC) is becoming one of the most common cancers overworld, which causes a high rate of death in patients. circRNAs are non-coding RNAs(ncRNAs), which have been reported to be involved in the development of many cancers, including CRC. However, the exact mechanism that how circRNAs function through in CRC remains unclear. In this study, we firstly used GEO database and bioinformatic methods to identify the significant changed circRNAs, with circSKA3 being the most significantly upregulated circRNAs in CRC tissues. PCR results further confirmed higher expression of circSKA3 in CRC patients. CCK-8, scratch, and transwell assays indicated that circSKA3 could promote the proliferation, migration, and invasion of CRC cell lines for cell detection. Dual-luciferase assays were carried out to detect the downstream targets of circSKA3, and a binding site between circSKA3 and miR-1238 was identified and miR-1238 could also combine with YTHDF2. Overexpression of YTHDF2 rescued the decreased cell proliferation, migration, and invasion caused by miR-1238 overexpression. RIP assay further indicated that YTHDF2 could decrease the methylation of STAT5A. In summary, our study found that circSKA3 was upregulated in CRC tissues comparing with normal tissues. circSKA3 could increase the expression ofYTHDF2 through sponging miR-1238 to decrease the methylation of STAT5A, which could provide a novel target for CRC treatment.

Incidence, risk factors, and predictive modeling of stoma site incisional hernia after enterostomy closure: a multicenter retrospective cohort study.

PURPOSE: Stoma site incisional hernia (SSIH) is a common complication, but its incidence and risk factors are not well known. The objective of this study is to explore the incidence and risk factors of SSIH and build a predictive model. METHODS: We performed a multicenter retrospective analysis on the patients who underwent enterostomy closure from January 2018 to August 2020. Patient's general condition, perioperative, intraoperative, and follow-up information was collected. The patients were divided into control group (no occurrence) and observation group (occurrence) according to whether SSIH occurred. Univariate and multivariate analysis were used to evaluate the risk factors of SSIH, following which we constructed a nomogram for SSIH prediction. RESULTS: One hundred fifty-six patients were enrolled in the study. The incidence of SSIH was 24.4% (38 cases), of which 14 were treated with hernia mesh repair, and the others were treated with conservative treatment. Univariate and multivariate analysis showed that age ≥ 68 years (OR 1.045, 95% CI 1.002 ~ 1.089, P = 0.038), colostomy (OR 2.913, 95% CI 1.035 ~ 8.202, P = 0.043), BMI ≥ 25 kg/m2 (OR 1.181, 95% CI 1.010 ~ 1.382, P = 0.037), malignant tumor (OR 4.838, 95% CI 1.508 ~ 15.517, P = 0.008) and emergency surgery (OR 5.327, 95% CI 1.996 ~ 14.434, P = 0.001) are the independent risk factors for SSIH. CONCLUSIONS: Based on the results, a predictive model for the occurrence of SSIH was constructed to screen high-risk groups of SSIH. For patients at high risk for SSIH, how to deal with the follow-up and prevent the occurrence of SSIH is worth further exploration.

Decorin-mediated inhibition of cholangiocarcinoma cell growth and migration and promotion of apoptosis are associated with E-cadherin in vitro.

Emerging evidences have shown that decorin expression is significantly reduced in many cancer tissues and cancer cells. However, its biological role and clinical significance in cholangiocarcinoma development and progression are unknown. In this study, immunohistochemistry was conducted to investigate the expression of decorin in cholangiocarcinomas. The results showed that decorin levels markedly decreased in 44 cholangiocarcinoma tissues compared to 40 adjacent normal tissues. The analysis between decorin expression and clinicopathological characteristics in cholangiocarcinoma patients showed that patients with low levels of decorin expression had a relatively poor prognosis. Moreover, recombinant human decorin treatment and overexpression of decorin in cholangiocarcinoma cells could inhibit cell proliferation, migration, and invasion and promote apoptosis. Furthermore, the E-cadherin expression significantly increased after decorin overexpression or use of recombinant human decorin in cholangiocarcinoma cells. Our findings indicated that downregulation of decorin may be identified as a poor prognostic biomarker in cholangiocarcinomas. Also, decorin-mediated inhibition of cholangiocarcinoma cell growth, migration, and invasion and promotion of cell apoptosis might be through regulation of the expression of E-cadherin in vitro.

Infiltrating characteristics and prognostic value of tertiary lymphoid structures in resected gastric neuroendocrine neoplasm patients.

Objectives: Tertiary lymphoid structures (TLSs) are lymphocyte aggregates that play an anti-tumor role in most solid tumors. However, the functions of TLS in gastric neuroendocrine neoplasms (GNENs) remain unknown. This study aimed to determine the characteristics and prognostic values of TLS in resected GNEN patients. Methods: Haematoxylin-eosin, immunohistochemistry (IHC) and multiple fluorescent IHC staining were used to assess TLS to investigate the correlation between TLSs and clinicopathological characteristics and its prognostic value. Results: Tertiary lymphoid structures were identified in 84.3% of patients with GNEN. They were located in the stromal area or outside the tumor tissue and mainly composed of B and T cells. A high density of TLSs promoted an anti-tumor immune response in GNEN. CD15+ TANs and FOXP3+ Tregs in TLSs inhibited the formation of TLSs. High TLS density was significantly associated with prolonged recurrence-free survival (RFS) and overall survival (OS) of GNENs. Univariate and multivariate Cox regression analyses revealed that TLS density, tumor size, tumor-node-metastasis (TNM) stage and World Health Organisation (WHO) classification were independent prognostic factors for OS, whereas TLS density, tumor size and TNM stage were independent prognostic factors for RFS. Finally, OS and RFS nomograms were developed and validated, which were superior to the WHO classification and the TNM stage. Conclusion: Tertiary lymphoid structures were mainly located in the stromal area or outside the tumor area, and high TLS density was significantly associated with the good prognosis of patients with GNEN. Incorporating TLS density into a nomogram may improve survival prediction in patients with resected GNEN.

Turning Tertiary Lymphoid Structures (TLS) into Hot Spots: Values of TLS in Gastrointestinal Tumors.

Tertiary lymphoid structures (TLSs) are ectopic lymphocyte aggregation structures found in the tumor microenvironment (TME). Emerging evidence shows that TLSs are significantly correlated with the progression of gastrointestinal tumors, patients' prognosis, and the efficacy of adjuvant therapy. Besides, there are still some immunosuppressive factors in the TLSs that may affect the anti-tumor responses of TLSs, including negative regulators of anti-tumor immune responses, the immune checkpoint molecules, and inappropriate tumor metabolism. Therefore, a more comprehensive understanding of TLSs' responses in gastrointestinal tumors is essential to fully understand how TLSs can fully exert their anti-tumor responses. In addition, targeting TLSs with immune checkpoint inhibitors and vaccines to establish mature TLSs is currently being developed to reprogram the TME, further benefiting cancer immunotherapies. This review summarizes recent findings on the formation of TLSs, the mechanisms of their anti-tumor immune responses, and the association between therapeutic strategies and TLSs, providing a novel perspective on tumor-associated TLSs in gastrointestinal tumors.

Tissue specific imprinting on innate lymphoid cells during homeostasis and disease process revealed by integrative inference of single-cell transcriptomics.

Introduction: Innate lymphoid cells (ILCs) are key components of the immune system, yet the similarity and distinction of the properties across tissues under homeostasis, inflammation and tumor process remain elusive. Methods: Here we performed integrative inference of ILCs to reveal their transcriptional profiles and heterogeneity from single-cell genomics. We collected a large number of ILCs from human six different tissues which can represent unique immune niches (circulation, lymphoid tissue, normal and inflamed mucosa, tumor microenvironment), to systematically address the transcriptional imprinting. Results: ILCs are profoundly imprinted by their organ of residence, and tissue-specific distinctions are apparent under pathological conditions. In the hepatocellular carcinoma microenvironment, we identified intermediate c-kit+ ILC2 population, and lin-CD127- NK-like cells that expressed markers of cytotoxicity including CCL5 and IFNG. Additionally, CD127+CD94+ ILC1s were preferentially enriched in inflamed ileum from patients with Crohn's disease. Discussion: These analyses depicted a comprehensive characterization of ILC anatomical distribution and subset heterogeneity, and provided a base line for future temporal or spatial studies focused on tissue-specific ILC-mediated immunity.

Prediction values of tertiary lymphoid structures in the prognosis of patients with left- and right-sided colon cancer: a multicenter propensity score-matched study.

BACKGROUND: Tertiary lymphoid structures (TLS) are the lymphocyte aggregates that play a key role in the vast majority of solid tumors including colon cancer, displaying an antitumor effect under most circumstances. The heterogeneity between left- and right-sided colon cancer (LCC and RCC) encompasses various aspects, such as clinical manifestations, pathological features, and immune responses. However, the function and prognostic significance of TLS within LCC and RCC have yet to be fully understood. METHODS: A retrospective analysis was performed on 2612 patients who underwent radical resection for LCC or RCC without distant metastasis in multiple medical centers. Utilizing propensity score matching, 121 patients with LCC and 121 patients with RCC were selected for the training set. An external validation set including 64 patients with LCC and 64 patients with RCC were also employed. Hematoxylin-eosin and immunohistochemical staining were used to assess TLS and the proportion of various immune cells. Clinical characteristics and prognostic values of TLS in patients with LCC and RCC were analyzed. Nomograms were constructed for LCC and RCC to predict 3-year and 5-year overall survival (OS), respectively. RESULTS: For LCC and RCC patients, TLS was located in the interstitial region or outside the tumor tissue and mainly consisted of B cells and T cells. The TLS quantity and density in RCC were higher than those of LCC. In multivariate Cox regression analysis, TLS density ( P =0.014), vascular invasion ( P =0.019), and AJCC stage ( P =0.026) were independent prognostic factors for 5-year OS of RCC. For LCC patients, AJCC stage ( P =0.024), tumor differentiation ( P =0.001), and tumor budding ( P =0.040) emerged as independent prognostic factors for 5-year OS. Similar results were obtained in the external verification set. Separate nomograms for RCC and LCC were developed, displaying improved prediction performance compared to the AJCC 8th edition TNM staging system. CONCLUSIONS: Differences in TLS quantity and density were observed between LCC and RCC, suggesting that a nomogram based on TLS density could more effectively predict survival for RCC patients. Furthermore, a nomogram based on tumor budding was recommended for better prediction of LCC patient survival. Taken together, these results suggested that the immune and clinical characteristics of colon cancer at left and right side were substantially different, which may lead to the use of different prediction model and the development of individual treatment strategy.

Construction of a novel mRNA-miRNA-lncRNA network and identification of potential regulatory axis associated with prognosis in colorectal cancer liver metastases.

Liver metastasis is a leading cause of death in patients with colorectal cancer (CRC). Increasing evidence demonstrates that competing endogenous RNA (ceRNA) networks play important roles in malignant cancers. The purpose of this study was to identify molecular markers and build a ceRNA network as a significant predictor of colorectal liver metastases (CRLM). By integrated bioinformatics analysis, we found that apolipoprotein C1 (APOC1) was upregulated in CRLM and associated with prognosis in patients with CRC and thereby established an APOC1-dependent ceRNA network. By survival analysis, expression analysis, and correlation analysis of each element in the ceRNA network, we identified that ZEB1-AS1, miR-335-5p and APOC1 regulated each other. We further experimentally confirmed that ZEB1-AS1 promoted a CRC progression via regulating the expression of miR-335-5p that controlled the expression of APOC1. Our findings indicate that the ZEB1-AS1-miR-335-5p-APOC1 ceRNA regulatory network is significantly valuable for better prognosis of patients with CRC and as a new therapeutic target for the treatment of CRLM.

Polo-like kinase 1 is involved in apoptosis, invasion, and metastasis of pancreatic ductal adenocarcinoma.

BACKGROUND: Polo-like kinase 1 (Plk1) is overexpressed in different types of carcinomas, and it is widely pursued as a novel target for treatment of neoplasms. However, the role of Plk1 in invasion and metastasis of pancreatic cancer has not been reported. METHODS: In order to evaluate whetherPlk1 can potentially serve as a therapeutic target in pancreatic cancer, we herein explore and discuss the relationship between the inhibition of Plk1 by RNA interference (RNAi) and invasion and metastasis of pancreatic cancer cells. For this, three pancreatic cancer cell lines (AsPC-1, BxPC-3, and PANC-1) were studied. Plk1-specific short hairpin RNAs (shPlk1) were introduced into these cell lines by viral transduction. RESULTS: We found that Plk1 mRNA and protein levels were significantly reduced in the shPlk1 group. Moreover, knockdown of Plk1 expression by shPlk1 promoted apoptosis, while cell invasion and metastasis potentials were significantly reduced. CONCLUSIONS: Plk1 expression levels were closely correlated with proliferation, invasion, and metastasis of pancreatic cancer, and inhibition of Plk1 expression by RNAi could promote cell apoptosis and suppress metastasis and invasion of pancreatic cancer cells in vitro. Furthermore, Plk1 might constitute novel target for treatment of pancreatic cancer, with inhibition of Plk1 potentially providing a new strategy for the prevention of pancreatic cancer invasion and metastasis.

Combination of PI3K/Akt Pathway Inhibition and Plk1 Depletion Can Enhance Chemosensitivity to Gemcitabine in Pancreatic Carcinoma.

The prognosis of pancreatic cancer (PC) remains pessimistic because of the difficulty in early diagnosis as well as the little advance in chemotherapy. Although being the first-line chemotherapy drug for PC at present, gemcitabine still has some disadvantages, such as low drug sensitivity and significant side effects. Thus, how to further improve the sensitivity of PC cells to gemcitabine is still a difficult subject in the field of pancreatic cancer-treatment. Polo-like kinase 1 (Plk1) is closely related to poor outcome in many malignant tumors and its high expression is linked to chemoresistance in PC. As a downstream gene activated by PI3K/Akt signal pathway, we assumed that the targeted depletion of Plk1 could contribute to the chemosensitization induced by synergistic drug interaction of PI3K inhibitor LY294002 together with gemcitabine. To analyze effect of Plk1 in chemotherapy, we constructed two recombinant adenoviral vectors which carry enhanced green fluorescent protein (rAd-EGFP) and Plk1-shRNA (rAd-shPlk1), respectively. Both inhibition of PI3K/Akt signal pathway through PI3K inhibitor LY294002 and targeted depletion of Plk1 via recombinant adenoviral shRNA can cause chemosensitization, and the targeted depletion of Plk1 can enhance the chemosensitization of LY294002. Thus, the gene therapy like targeted depletion of Plk1 may create new perspectives for chemosensitization of PC.

Regulation of cell apoptosis and proliferation in pancreatic cancer through PI3K/Akt pathway via Polo-like kinase 1.

Pancreatic cancer has a poor prognosis. It is reported that the PI3K/Akt pathway is activated in many cancers, and inhibition of the PI3K/Akt pathway can induce cell apoptosis in most cancers. Polo-like kinase 1 (Plk1) is also overexpressed in most malignancies, and it controls multiple aspects of mitosis and apoptosis. Previous studies identified that PI3K/Akt-dependent phosphorylation of Plk1-Ser99 is required for metaphase-anaphase transition. In this study, we aimed to investigate the molecular mechanism of PI3K/Akt pathway regulating cell proliferation and apoptosis in pancreatic cancer cell lines (AsPC-1, BxPC-3, PANC-1). Immunohistochemistry (IHC) was used to assess Akt levels in human pancreatic tissues and pancreatic cancer tissues. MTT assay was used to detect cell proliferation. The mRNA was quantified by quantitative reverse transcription-PCR. Western blot analysis was used to detect the protein levels of p-Akt, Akt, Plk1, BAX, Bcl-2, XIAP, cleaved caspase-3 and caspase-3. Recombinant adenovirus vector containing Plk1-shRNA was constructed to inhibit Plk1 expression. Cell apoptosis was detected by flow cytometry and the apoptosis of tumor xenograft was assessed by TUNEL assay. The study showed that inhibition of PI3K/Akt pathway can induce cell apoptosis and reduce cell proliferation by downregulating Plk1 in vitro and in vivo. Additionally, Plk1 inhibition can lead to cancer cell apoptosis through inactivating XIAP, activating caspase-3, upregulating BAX and downregulating Bcl-2. Therefore, this study provided the molecular mechanism of PI3K/Akt pathway and Plk1 in the pancreatic cancer cell proliferation and apoptosis, which may benefit for the therapy of pancreatic cancer.