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Background: Cancer is a thorny problem which cannot be conquered by mankind at present and recent researchers have put their focus on tumor microenviroment. Neutrophils, the prominent leukocytes in peripheral blood that accumulate in tumours, serves as frontline cells in response to tumour progression owing to the rapid development of micro biotechnology. Hence, targeted therapy with these neutrophils has made targeting treatment a promising field in cancer therapy. Main body: We broadly summarise some studies on the phenotypes and functions of tumour‐associated neutrophils as well as the unique web‐like products of neutrophils that play a role in cancer progression—neutrophil extracellular traps—and the interactions between neutrophils and the tumour microenvironment. Moreover, several targeted neutrophils therapeutic studies have made some progress and provided potential strategies for the treatment of cancer. Conclusion: This review aims to offer a holistic perspective on therapeutic interventions targeting neutrophils to further inspire more researches on cancer therapies. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A) modification of gene transcripts plays critical roles in cancer. Here we report transcriptomic m6A profiling in 98 tissue samples from 65 individuals with pancreatic ductal adenocarcinoma (PDAC). We identify 17,996 m6A peaks with 195 hyper-methylated and 93 hypo-methylated in PDAC compared with adjacent normal tissues. The differential m6A modifications distinguish two PDAC subtypes with different prognosis outcomes. The formation of the two subtypes is driven by a newly identified m6A regulator CSTF2 that co-transcriptionally regulates m6A installation through slowing the RNA Pol II elongation rate during gene transcription. We find that most of the CSTF2-regulated m6As have positive effects on the RNA level of host genes, and CSTF2-regulated m6As are mainly recognized by IGF2BP2, an m6A reader that stabilizes mRNAs. These results provide a promising PDAC subtyping strategy and potential therapeutic targets for precision medicine of PDAC. N6-methyladenosine (m6A) modification has important implications in different cancer subtypes. Here, the authors perform transcriptomic m6A profiling to identify two subtypes of pancreatic ductal adenocarcinoma with differential m6A modifications and different clinical outcomes, which is driven by m6A regulator CSTF2. [ABSTRACT FROM AUTHOR]

As a new infectious disease, COVID-19 is spread through the respiratory tract in most cases. Its source and pathological mechanism are not clear. The most common clinical feature is pulmonary infection. Also, a lot patients have gastrointestinal symptoms. Angiotensin-converting enzyme 2 (ACE2) is a functional cellular receptor for SARS-CoV-2, which is like SARS-CoV, a coronavirus associated with severe acute respiratory syndrome (SARS) outbreak in 2003. The tissues and cells expressing ACE2 are potential targets for SARS-CoV-2 infection, and the high expression of ACE2 in intestinal epithelial cells marks that SARS-CoV-2 may directly infect intestinal epithelial cells. Recent studies also suggest that SARS-CoV-2 existed and replicated in intestinal environment for a long time. The interaction between SARS-CoV-2 and RAS system leads to the decrease of local anti-inflammatory ability. The virus cycle leads to excessive imbalance of immune response and cytokine release. The downregulation of ACE2 after viral infection leads to gastrointestinal dysfunction. The above are the causes of gastrointestinal symptoms. Here, we reviewed the possible causes and mechanisms of gastrointestinal symptoms caused by COVID-19. Additionally, we discussed the influence of gastrointestinal symptoms on the prognosis of patients. [ABSTRACT FROM AUTHOR]

In recent years, an increasing number of studies have reported that intestinal microbiota have an important effect on tumour immunity by affecting the tumour microenvironment (TME). The intestinal microbiota are closely associated with various immune cells, such as T lymphocytes, natural killer cells (NK cells) and macrophages. Some bacteria, such as Akkermansia muciniphila (A. muciniphila) and Lactobacillus reuteri (L. reuteri), have been shown to improve the effect of tumour immunity. Furthermore, microbial imbalance, such as the increased abundance of Fusobacterium nucleatum (F. nucleatum) and Helicobacter hepaticus (H. hepaticus), generally causes tumour formation and progression. In addition, some microbiota also play important roles in tumour immunotherapy, especially PD‐L1‐related therapies. Therefore, what is the relationship between these processes and how do they affect each other? In this review, we summarize the interactions and corresponding mechanisms among the intestinal microbiota, immune system and TME to facilitate the research and development of new targeted drugs and provide new approaches to tumour therapy. [ABSTRACT FROM AUTHOR]

Cancer metastasis is a symptom of adverse prognosis, a prime origin of therapy failure, and a lethal challenge for cancer patients. N 6-methyladenosine (m6A), the most prevailing modification in messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs) of higher eukaryotes, has attracted increasing attention. Growing studies have verified the pivotal roles of m6A methylation in controlling mRNAs and ncRNAs in diverse physiological processes. Remarkably, recent findings have showed that aberrant methylation of m6A-related RNAs could influence cancer metastasis. In this review, we illuminate how m6A modifiers act on mRNAs and ncRNAs and modulate metastasis in several cancers, and put forward the clinical application prospects of m6A methylation. [ABSTRACT FROM AUTHOR]

Background: Previous studies on the systemic immune-inflammation index (SII), which is based on platelet, neutrophil and lymphocyte counts, as a prognostic marker in patients with colorectal cancer (CRC) yielded inconsistent results. The aim of this study was to evaluate the prognostic and clinicopathological role of SII in CRC via meta-analysis. Methods: A comprehensive literature survey was performed on PubMed, Web of Science, Embase and the Cochrane Library databases to include studies published up to 6 April 2020. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were computed to estimate the prognostic and clinicopathological value of SII in CRC. Results: A total of 12 studies published between 2016 and 2019 were included in our meta-analysis. The combined analysis showed that high SII levels were significantly associated with worse overall survival (OS; HR = 1.61, 95% CI = 1.21–2.13, p = 0.001) and progression-free survival (HR = 1.74, 95% CI = 1.26–2.39, p = 0.001) in CRC. Moreover, elevated SII was also correlated with poor tumor differentiation (OR = 1.60, 95% CI = 1.27–2.02, p < 0.001), presence of distant metastasis (OR = 2.27, 95% CI = 1.10–4.67, p = 0.026), ECOG PS of 1–2 (OR = 1.98, 95% CI = 1.39–2.84, p < 0.001) and tumor size ⩾5 cm (OR = 1.49, 95% CI = 1.18–1.88, p = 0.001). However, high SII was not significantly associated with sex, tumor location, lymph node metastasis, or age in patients with CRC. Conclusion: Our meta-analysis indicated that high SII levels predicted poor prognosis in CRC. In addition, an elevated SII was also associated with clinical factors, implying higher malignancy of the disease. [ABSTRACT FROM AUTHOR]

Aimei Rong,2 Quanbo Zhou,3 Wenlu Li41Department of Emergency Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450000, China; 2Department of Gastroenterology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450000, China; 3Department of Anus and Intestine Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450000, China; 4Department of Stomatology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450000, China Background: Claudin 8 (CLDN8), an integral membrane protein that constitutes tight junctions in cell membranes, was recently implicated in tumor progression. However, its roles in colorectal cancer (CRC) progression and metastasis remain unknown. Methods: In this study, we examined the effect of CLDN8 on the progression of CRC, including cell proliferation, migration, and invasion, and determines its underlying molecular mechanism using in vitro CRC cell lines and in vivo mouse xenograft models. Results: We found that CLDN8 expression in human CRC tissues was significantly higher than that in adjacent normal tissues. The knockdown of CLDN8 markedly suppressed the proliferation, migration, and invasion of SW480 and HT-29 CRC cells, whereas the overexpression of CLDN8 notably promoted tumor progression in SW480 and HT-29 CRC cells. Mechanistic studies revealed that CLDN8 upregulated p-ERK (p-PKB/AKT) and MMP9 in CRC cells. Notably, the MAPK/ERK inhibitor PD98095 dramatically attenuated the effects of CLDN8 on p-ERK and MMP9. Moreover, PD98095 remarkably blocked the tumor-promoting activity of CLDN8. The knockdown of CLDN8 also inhibited the in vivo tumor growth in a nude mouse xenograft model. Collectively, CLDN8 promoted CRC cell proliferation, migration, and invasion, at least in part, by activating the MAPK/ERK signaling pathway. Conclusion: These findings suggest that CLDN8 exhibits an oncogenic effect in human CRC progression. [ABSTRACT FROM AUTHOR]

Background: Colon adenocarcinoma (COAD) is ranked as the third most commonly diagnosed cancer in both women and men, and it is the most frequently occurring malignant tumor. Dynactin is a protein compound based on multiple subunits, including dynactin 1–6 (DCTN1–6), in most categories of cytoplasmic dynein performance in eukaryotes. Nevertheless, correlations between the DCTN family and the prognosis and diagnosis of COAD remain unidentified.Methods: Statistics for DCTN mRNA expression in patients with COAD were acquired from The Cancer Genome Atlas. Kaplan–Meier analyses and a Cox regression model were applied to determine overall survival, with computation of HRs and 95% CIs. Several online data portals were used to assess the biological process, and pathway examination was performed using the Kyoto Encyclopedia of Genes and Genomes to predict the biological functionality of DCTN genes.Results: We found that high expression of DCTN4 was linked with satisfactory results for overall survival (P=0.042, HR=0.650, 95% CI 0.429–0.985). The expression of DCTN1, DATN2, and DCTN4 was closely correlated with the frequency of colon tumors (P<0.001, area under the curve [AUC]=0.8811, 95% CI 0.8311–0.9312; P<0.001, AUC=0.870, 96% CI 0.833–0.9071; and P=0.0051, AUC=0.6317, 95% CI 0.5725–0.6908, respectively). In the enrichment examination, the level of gene expression was related to the cell cycle, cell apoptosis, and the cell metastasis pathway.Conclusion: The expression levels of DCTN1, DCTN2, and DCTN4 could allow differentiation between cancer-bearing tissues and paracancerous tissue. These genes can be applied as biomarkers to predict the prognosis and diagnosis of COAD. [ABSTRACT FROM AUTHOR]

The present study aimed to determine how the expression and function of HOTTIP modifies, and regulates the metabotropic glutamate receptor 1 (mGluR1) to affect human pancreatic cancer cell viability. HOTTIP expression was higher in human pancreatic cancer tissue compared with in para-carcinoma tissue. However, downregulation of HOTTIP expression was revealed to significantly reduce cell viability, induce apoptosis, promote caspase-3 and caspase-8 activities and increase Bax expression in pancreatic cancer cells. Additionally, downregulation of HOTTIP expression significantly suppressed mGluR1 and mitigated activation of the phosphoinositide 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) pathway in pancreatic cancer cells. To the best of our knowledge, the present study is the first to identify that the anticancer effect of HOTTIP against human pancreatic cancer functions the mGluR1 pathway. [ABSTRACT FROM AUTHOR]

Noncoding RNAs (ncRNAs) can be divided into microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), pRNAs, and tRNAs. Traditionally, miRNAs exert their biological function mainly through the inhibition of translation via the induction of target RNA transcript degradation. lncRNAs and circRNAs were once considered to have no potential to code proteins. Here, we will review the current knowledge on ncRNAs in relation to their origins, characteristics, and functions. We will also review how ncRNAs work as competitive endogenous RNA, gene transcription and expression regulators, and RNA-binding protein sponges in colorectal cancer (CRC). Notably, except for the abovementioned mechanisms, recent advances revealed that lncRNAs can also act as the precursor of miRNAs, and a small portion of lncRNAs and circRNAs was verified to have the potential to code proteins, providing new evidence for the significance of ncRNAs in CRC tumorigenesis and development. [ABSTRACT FROM AUTHOR]