Long Noncoding RNA UCA1 in Gastrointestinal Cancers: Molecular Regulatory Roles and Patterns, Mechanisms, and Interactions

Alteration of the gut microbiota in patients with lung cancer accompanied by chronic obstructive pulmonary diseases

Aim

To explore the abundance and diversity of the gut microbiota in patients with lung cancer accompanied by chronic obstructive pulmonary disease (LC-COPD).

Methods

The study cohort comprised 15 patients with LC-COPD, 49 patients with lung cancer, and 18 healthy control individuals. ELISA was used to detect inflammatory factors in venous blood. 16S rDNA sequencing was performed to determine the abundance and diversity of the gut microbiota. Gas chromatography-mass spectrometry was used to determine the concentration of short-chain fatty acids (SCFAs) in feces samples.

Results

The α-diversity index indicated that the richness and diversity of the gut microbiota were lower in patients with LC-COPD compared with patients with lung cancer and controls. Principal component analysis revealed significant differences among the three groups (P < 0.05). The linear discriminant analysis effect size algorithm indicated that the o_Lactobacillales, g_Lactobaccillus, f_Lactobaccillaceae, s_Lactobaccillus_oris, c_Bacilli, g_Anaerofustis, s_uncultured organism, and s_bacterium_P1C10 species were prevalent in patients with LC-COPD, while the g_Clostridium_XIVa and g_Butyricicoccus species were prevalent in patients with lung cancer. Furthermore, the concentrations of the SCFAs butyric acid, isobutyric acid, isovaleric acid, and valeric acid tended to be lower in patients with LC-COPD compared with patients with lung cancer and healthy controls, although these intergroup differences were not significant (P > 0.05). Patients with lung cancer had the lowest serum concentration of tumor necrosis factor (TNF)-a. There were no intergroup differences in the concentrations of other inflammatory factors.

Conclusions

The present study indicated that the abundance and structure of the gut microbiota is altered, and the concentrations of SCFAs may be decreased in patients with LC-COPD. In addition, patients with lung cancer had the lowest serum concentration of TNF-a.

LncRNA-MUF: A Novel Oncogenic Star with Potential as a Biological Marker and Therapeutic Target for Gastrointestinal Malignancies

Gastrointestinal (GI) cancers pose a significant global health challenge, characterized by a high incidence and poor prognosis. The delayed detection and occurrence of metastasis contribute to the overall low survival rates associated with these cancers. Therefore, there is an urgent need to identify novel molecular targets for effective GI cancer treatment. Recent research has shed light on the potential of long non-coding RNAs (lncRNAs) as promising targets in cancer therapy, given their strong association with carcinogenesis and profound impact on tumor development. Among these lncRNAs, lncRNA-MUF, also known as LINC00941, has emerged as a key player in oncogenic regulation, specifically implicated in the progression of various GI cancers, including esophageal, gastric, colorectal, hepatic, and pancreatic cancer. This review aims to provide an updated and focused analysis of the regulatory roles of LINC00941 in the initiation and progression of GI cancer. Our objective is to unravel the underlying molecular mechanisms through which LINC00941 influences GI cancer phenotypes both in vivo and in vitro, with a special emphasis on the key molecules and signaling pathways involved. Additionally, LINC00941 has demonstrated clinical significance in terms of clinical pathology, prognosis, and diagnosis in GI tumors, further reinforcing its potential as a novel therapeutic target.

Lymph node metastasis-related lncRNA GAS6-AS1 facilitates the progression of esophageal squamous cell carcinoma

Background

Lymph node metastasis is the main type of metastasis in esophageal squamous cell carcinoma (ESCC), especially when the primary tumor invasion depth reaches above the adventitia layer (T3 stage), the incidence of lymph node metastasis increases sharply. Abnormal expression of long non-coding RNAs (lncRNAs) has been confirmed in ESCC, but there are still many unknown connections between lncRNAs and lymph node metastasis.

Methods

We used transcriptome sequencing (RNA-seq) to analyze 10 pairs of ESCC tissues with primary tumor stage T3 and their paired normal epithelium. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to further verify the sequencing results, and survival curve analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis were used to investigate its clinical application value. We investigated the growth and metastasis effects of lncRNA GAS6-AS1 on ESCC cell lines TE-1 and KYSE410 in vitro and in vivo. Other functional experiments included cell apoptosis and cell cycle experiments.

Results

Based on our RNA-seq data, lncRNA GAS6-AS1 is highly expressed in ESCC tissues, especially in cancer tissues with lymph node metastasis. The qRT-PCR experiment analysis showed that high expression of GAS6-AS1 was related to poor tumor differentiation and tumor stage. Logistic regression analysis showed that it was an independent risk factor for lymph node metastasis, and ROC analysis validated that it could predict lymph node metastasis. Further survival analysis suggested that high expression of GAS6-AS1 was associated with patients' poor prognosis. In vitro experiments, knocking down GAS6-AS1 inhibited the growth and metastasis of ESCC cells and inhibited tumor growth in vivo. In addition, knocking down GAS6-AS1 can inhibit cell cycle and promote cell apoptosis.

Conclusions

Our results revealed that lncRNA GAS6-AS1 obtained from RNA-seq can be used as an independent risk factor for ESCC lymph node metastasis and an effective biomarker to predict, and that it was related to the growth and metastasis of ESCC. It may represent a new biomarker to aid in the assessment of the lymph node metastasis of ESCC.

SNHG15-Mediated Localization of Nucleolin at the Cell Protrusions Regulates CDH2 mRNA Expression and Cell Invasion

LncRNAs are emerging as important regulators of gene expression by controlling transcription in the nucleus and by modulating mRNA translation in the cytoplasm. In this study, we reveal a novel function of lncRNA SNHG15 in mediating breast cancer cell invasion through regulating the local translation of CDH2 mRNA. We show that SNHG15 preferentially localizes at the cellular protrusions or cell leading edge and that this localization is directed by IMP1, a multifunctional protein involved in many aspects of RNA regulation. We demonstrate that SNHG15 also forms a complex with nucleolin, allowing nucleolin to be co-transported with SNHG15 to the cell protrusions, where the accumulated nucleolin is able to bind to CDH2 mRNA. Interaction with nucleolin stabilizes local CDH2 mRNA and regulates its translation, thus promoting cell invasive potential. Our findings reveal an underlying mechanism by which lncRNA could serve as a carrier to transport a protein regulator into a specific cell compartment to enhance target mRNA expression.

Serum LINC00152 and UCA1 in HCV-Induced Hepatocellular Carcinoma: Clinical Significance and Prognostic Value

Background

Despite significant advancements in the molecular characterization of hepatocellular carcinoma (HCC), no oncogene addiction has been discovered. Long noncoding RNAs (lncRNAs) have a lot of promise as cancer biomarkers. LINC00152 and UCA1 have shown potential as diagnostic, prognostic, and therapeutic targets for human cancers.

Aim

To investigate the diagnostic and prognostic potential of serum LINC00152 and UCA1 in hepatocellular carcinoma (HCC).

Methods

The expression levels of LINC00152 and UCA1 in blood samples from 120 patients (60 with HCC, 60 with liver cirrhosis) and 40 healthy subjects were assessed using real-time qRT-PCR.

Results

Serum LINC00152 and UCA1 expression were considerably higher in HCC patients compared to patients with liver cirrhosis and the healthy controls (p<0.001 and p<0.001 respectively). And their expressions in the liver cirrhosis group were significantly higher than in healthy controls. Both lncRNAs performed well in the ROC analysis, distinguishing HCC patients from patients with liver cirrhosis. Higher levels of LINC00152 expression were linked to lesions in both lobes of the liver (p=0.02), while higher levels of UCA1 expression were linked to vascular invasion and the late stage (p=0.01, p=0.03 respectively). The multivariate analysis showed that a high level of LINC00152 in the blood was an independent indicator of a bad outcome for HCC patients (HR=2.23, 95% CI= 1.30-5.29, p=0.03).

Conclusion

Serum LINC00152 and UCA1 expression were upregulated in patients with HCC, suggesting their use as non-invasive biomarkers for HCC. Furthermore, LINC00152 has the potential to serve as a prognostic indicator.

UCA1 executes an oncogenic role in pancreatic cancer by regulating miR-582-5p/BRCC3

Background

As a fatal disease, the mechanism of pancreatic cancer is unclear. Urothelial carcinoma antigen 1(UCA1), a long noncoding RNA (lncRNA) that was first reported in bladder cancer, acts as an oncogene. However, the regulatory role and mechanism of UCA1 in pancreatic cancer remain unknown. This study aims to investigate the expression level and prognostic value of UCA1 in pancreatic cancer tissues, the effects and mechanism of UCA1 in regulating cell proliferation, apoptosis and metastasis.

Methods

UCA1 expression levels in tissues were detected by in situ hybridization (ISH) and the prognostic value was evaluated by univariate and multivariate survival analysis. For in vitro experiments, proliferation was evaluated by a cell count kit assay, Edu experiments, and a clone formation assay. Apoptosis was evaluated by fluorescence-activated cell sorting flow-cytometry. Cell migration and invasion capacities were detected by wound healing and transwell assays. Western blots were performed to detect apoptotic associated molecules and epithelial-mesenchymal transition (EMT) markers. For the in vivo experiment, subcutaneous transplantation models of pancreatic cancer in nude mice were established to observe the tumor growth. The regulatory mechanism of UCA1 was explored by proteomics, bioinformatic analysis, luciferase reporter assays, and rescue experiments.

Results

ISH staining revealed that UCA1 levels between cancer tissues (n=94) and tumor-adjacent tissues (n=73) did not show significant differences. Survival analysis indicated that high expression of UCA1 was an unfavorable prognosis factor for pancreatic cancer. Downregulation of UCA1 by siRNA significantly inhibited cell proliferation, decreased the capacities of cell migration and invasion, induced cell apoptosis, and inhibited EMT. Furthermore, we demonstrated that UCA1 positively regulated the expression of BRCC3 by inhibiting miR-582-5p. Rescue experiments indicated that either inhibiting the expression of miR-582-5p or enhancing expression of BRCC3 could partly attenuate the antitumor effects of downregulation of UCA1.

Conclusion

UCA1 acted as an oncogene in pancreatic cancer by partly regulating miR-582-5p/BRCC3, which could be a new therapeutic target for pancreatic cancer.

Crosstalk between colorectal cancer cells and cancer-associated fibroblasts in the tumor microenvironment mediated by exosomal noncoding RNAs

Colorectal cancer (CRC) is a common malignant tumor of the digestive system, and its morbidity rates are increasing worldwide. Cancer-associated fibroblasts (CAFs), as part of the tumor microenvironment (TME), are not only closely linked to normal fibroblasts, but also can secrete a variety of substances (including exosomes) to participate in the regulation of the TME. Exosomes can play a key role in intercellular communication by delivering intracellular signaling substances (e.g., proteins, nucleic acids, non-coding RNAs), and an increasing number of studies have shown that non-coding RNAs of exosomal origin from CAFs are not only closely associated with the formation of the CRC microenvironment, but also increase the ability of CRC to grow in metastasis, mediate tumor immunosuppression, and are involved in the mechanism of drug resistance in CRC patients receiving. It is also involved in the mechanism of drug resistance after radiotherapy in CRC patients. In this paper, we review the current status and progress of research on CAFs-derived exosomal non-coding RNAs in CRC.

Phytochemicals of Withania somnifera as a Future Promising Drug against SARS-CoV-2: Pharmacological Role, Molecular Mechanism, Molecular Docking Evaluation, and Efficient Delivery

Coronavirus disease (COVID-19) has killed millions of people since first reported in Wuhan, China, in December 2019. Intriguingly, Withania somnifera (WS) has shown promising antiviral effects against numerous viral infections, including SARS-CoV and SARS-CoV-2, which are contributed by its phytochemicals. This review focused on the updated testing of therapeutic efficacy and associated molecular mechanisms of WS extracts and their phytochemicals against SARS-CoV-2 infection in preclinical and clinical studies with the aim to develop a long-term solution against COVID-19. It also deciphered the current use of the in silico molecular docking approach in developing potential inhibitors from WS targeting SARS-CoV-2 and host cell receptors that may aid the development of targeted therapy against SARS-CoV-2 ranging from prior to viral entry until acute respiratory distress syndrome (ARDS). This review also discussed nanoformulations or nanocarriers in achieving effective WS delivery to enhance its bioavailability and therapeutic efficacy, consequently preventing the emergence of drug resistance, and eventually therapeutic failure.

LncRNA LINC01094 Promotes Cells Proliferation and Metastasis through the PTEN/AKT Pathway by Targeting AZGP1 in Gastric Cancer

Long noncoding RNAs (lncRNAs) were recently reported to play an essential role in multiple cancer types. Herein, through next-generation sequencing, we screened metastasis-driving molecules by using tissues from early-stage gastric cancer (GC) patients with lymph node metastasis, and we identified a lncRNA LINC01094, which was associated with the metastasis of GC. According to the clinical data from the TCGA, GSE15459, and GSE62254 cohorts, the high expression of LINC01094 was associated with an unfavorable prognosis. Moreover, 106 clinical GC and paired normal samples were collected, and the qRT-PCR results showed that the high expression of LINC01094 was associated with high T and N stages and a poor prognosis. We found that LINC01094 promotes the proliferation and metastasis of GC in vitro and in vivo. AZGP1 was found as the protein-binding partner of LINC01094 by using RNA pulldown and RNA-binding protein immunoprecipitation (RIP) assays. LINC01094 antagonizes the function of AZGP1, downregulates the expression of PTEN, and further upregulates the AKT pathway. Collectively, our results suggested that LINC01094 might predict the prognosis of GC patients and become the therapy target for GC.

Three Members of Transmembrane-4-Superfamily, TM4SF1, TM4SF4, and TM4SF5, as Emerging Anticancer Molecular Targets against Cancer Phenotypes and Chemoresistance

There are six members of the transmembrane 4 superfamily (TM4SF) that have similar topology and sequence homology. Physiologically, they regulate tissue differentiation, signal transduction pathways, cellular activation, proliferation, motility, adhesion, and angiogenesis. Accumulating evidence has demonstrated, among six TM4SF members, the regulatory roles of transmembrane 4 L6 domain family members, particularly TM4SF1, TM4SF4, and TM4SF5, in cancer angiogenesis, progression, and chemoresistance. Hence, targeting derailed TM4SF for cancer therapy has become an emerging research area. As compared to others, this review aimed to present a focused insight and update on the biological roles of TM4SF1, TM4SF4, and TM4SF5 in the progression, metastasis, and chemoresistance of various cancers. Additionally, the mechanistic pathways, diagnostic and prognostic values, and the potential and efficacy of current anti-TM4SF antibody treatment were also deciphered. It also recommended the exploration of other interactive molecules to be implicated in cancer progression and chemoresistance, as well as potential therapeutic agents targeting TM4SF as future perspectives. Generally, these three TM4SF members interact with different integrins and receptors to significantly induce intracellular signaling and regulate the proliferation, migration, and invasion of cancer cells. Intriguingly, gene silencing or anti-TM4SF antibody could reverse their regulatory roles deciphered in different preclinical models. They also have prognostic and diagnostic value as their high expression was detected in clinical tissues and cells of various cancers. Hence, TM4SF1, TM4SF4, and TM4SF5 are promising therapeutic targets for different cancer types preclinically and deserve further investigation.

The Functional Role of LncRNA UCA1 in Pancreatic Cancer: a mini-review

Pancreatic cancer (PaC) is a common malignant tumor of the digestive tract, with a 5-year survival rate of less than 5% and high mortality rate in the world. LncRNAs have been showed to possess multiple biological functions in growth, differentiation, and proliferation, which play an important role in different biological processes and diseases, especially in the development of tumors. LncRNA UCA1, which is firstly identified in human bladder cancer, has been showed to be a tumor promoter in pancreatic cancer. Recent researches have showed that UCA1 might promote pancreatic carcinogenesis and progression, and correlate with drug resistance. In this review, we address the biological function and regulatory mechanism of UCA1 in pancreatic cancer, which might give a new approach for clinical diagnosis and treatment.

Exosomal long non-coding RNAs: novel molecules in gastrointestinal cancers' progression and diagnosis

Gastrointestinal (GI) cancers arise in the GI tract and accessory organs, including the mouth, esophagus, stomach, liver, biliary tract, pancreas, small intestine, large intestine, and rectum. GI cancers are a major cause of cancer-related morbidity and mortality worldwide. Exosomes act as mediators of cell-to-cell communication, with pleiotropic activity in the regulation of homeostasis, and can be markers for diseases. Non-coding RNAs (ncRNAs), such as long non-coding RNAs (lncRNAs), can be transported by exosomes derived from tumor cells or non-tumor cells. They can be taken by recipient cells to alter their function or remodel the tumor microenvironment. Moreover, due to their uniquely low immunogenicity and excellent stability, exosomes can be used as natural carriers for therapeutic ncRNAs in vivo. Exosomal lncRNAs have a crucial role in regulating several cancer processes, including angiogenesis, proliferation, drug resistance, metastasis, and immunomodulation. Exosomal lncRNA levels frequently alter according to the onset and progression of cancer. Exosomal lncRNAs can therefore be employed as biomarkers for the diagnosis and prognosis of cancer. Exosomal lncRNAs can also monitor the patient's response to chemotherapy while also serving as potential targets for cancer treatment. Here, we discuss the role of exosomal lncRNAs in the biology and possible future treatment of GI cancer.

Evodiamine as an anticancer agent: a comprehensive review on its therapeutic application, pharmacokinetic, toxicity, and metabolism in various cancers

Evodiamine is a major alkaloid component found in the fruit of Evodia rutaecarpa. It shows the anti-proliferative potential against a wide range of cancers by suppressing cell growth, invasion, and metastasis and inducing apoptosis both in vitro and in vivo. Evodiamine shows its anticancer potential by modulating aberrant signaling pathways. Additionally, the review focuses on several therapeutic implications of evodiamine, such as epigenetic modification, cancer stem cells, and epithelial to mesenchymal transition. Moreover, combinatory drug therapeutics along with evodiamine enhances the anticancer efficacy of chemotherapeutic drugs in various cancers by overcoming the chemo resistance and radio resistance shown by cancer cells. It has been widely used in preclinical trials in animal models, exhibiting very negligible side effects against normal cells and effective against cancer cells. The pharmacokinetic and pharmacodynamics-based collaborations of evodiamine are also included. Due to its poor bioavailability, synthetic analogs of evodiamine and its nano capsule have been formulated to enhance its bioavailability and reduce toxicity. In addition, this review summarizes the ongoing research on the mechanisms behind the antitumor potential of evodiamine, which proposes an exciting future for such interests in cancer biology.

Apoptosis evasion via long non-coding RNAs in colorectal cancer

Long non-coding RNA (LncRNA) is a novel and diverse class of regulatory transcripts that are frequently dysregulated in numerous tumor types. LncRNAs are involved in a complicated molecular network, regulating gene expression, and modulating diverse cellular activities in different cancers including colorectal cancer (CRC). Evidence indicates that lncRNAs can be used as a potential biomarker for the prognosis and diagnosis of CRC as they are aberrantly expressed in CRC cells. The high expression or silencing of lncRNAs is associated with cell proliferation, invasion, metastasis, chemoresistance and apoptosis in CRC. LncRNAs exert both pro-apoptotic and anti-apoptotic functions in CRC. The expression of some oncogene lncRNAs is upregulated which leads to the inhibition of apoptotic pathways, similarly, the tumor suppressor lncRNAs are downregulated in CRC. In this review, we describe the function and mechanisms of lncRNAs to regulate the expression of genes that are involved directly or indirectly in controlling cellular apoptosis in CRC. Furthermore, we also discussed the different apoptotic pathways in normal cells and the mechanisms by which CRC evade apoptosis.

Establishment and Analysis of a Prognostic Model of Autophagy-Related lncRNAs in ESCA

Esophageal cancer (ESCA) is a malignant tumor of the upper gastrointestinal tract, with a high mortality rate and poor prognosis. Long noncoding RNAs (lncRNAs) play a role in the malignant progression of tumors by regulating autophagy. This study is aimed at establishing a prognostic model of autophagy-related lncRNAs in ESCA and provide a theoretical basis to determine potential therapeutic targets for ESCA. The transcriptome expression profiles were downloaded from The Cancer Genome Atlas (TCGA). We identified autophagy-related mRNAs and lncRNAs in ESCA using differential expression analysis and the Human Autophagy Database (HADb). Four differentially expressed autophagy-related lncRNAs with a prognostic value were identified using Cox regression and survival analyses. Furthermore, the combination of the selected lncRNAs was able to predict the prognosis of patients with ESCA more accurately than any of the four lncRNAs individually. Finally, we constructed a coexpression network of autophagy-related mRNAs and lncRNAs. This study showed that autophagy-related lncRNAs play an important role in the occurrence and development of ESCA and could become a new target for the diagnosis and treatment of this disease.

The Novel LncRNA WASH5P Inhibits Colorectal Cancer Carcinogenesis via Targeting AKT Signaling Pathway

Emerging evidence has shown that long non-coding RNAs (lncRNAs) play an important role in colorectal cancer (CRC) carcinogenesis, so more specific mechanisms of key lncRNAs in CRC initiation and development are needed. Here, we evaluated the expression profiles of lncRNAs in CRC tissues and identified a novel lncRNA generated from the pseudogene Wiskott-Aldrich syndrome protein (WASP) family homolog 5, termed lncRNA WASH5P. However, the role and potential molecular mechanism of this novel lncRNA in diseases, including CRC carcinogenesis, is unknown. Our present study found that WASH5P was significantly downregulated in CRC cell lines and tissues compared with normal controls. The ectopic expression of WASH5P in CRC cells could significantly inhibit CRC cell proliferation, invasion, and migration. In addition, WASH5P could increase the expression of E-cadherin and decrease Vimentin expression. WASH5P-overexpressing CRC cells developed tumors more slowly in different mouse models. Meanwhile, the overexpression of WASH5P could significantly inhibit AKT activation via suppressing AKT phosphorylation. The treatment of PI3K/AKT (phosphatidlinositol 3-kinase /protein kinase B) signaling agonist 740Y-P rescued WASH5P-reduced AKT phosphorylation and abolished the inhibitory effects of WASH5P on cell viability, migration, and invasion. Moreover, 740Y-P restored the WASH5P-induced downregulation of p-AKT and vimentin and the upregulation of E-cadherin via Western blot. In summary, our findings suggested that the novel lncRNA WASH5P might be a potential candidate biomarker and therapeutic target that could inhibit CRC by repressing the AKT signaling pathway.

Matrix Metalloproteinases in Chemoresistance: Regulatory Roles, Molecular Interactions, and Potential Inhibitors

Cancer is one of the major causes of death worldwide. Its treatments usually fail when the tumor has become malignant and metastasized. Metastasis is a key source of cancer recurrence, which often leads to resistance towards chemotherapeutic agents. Hence, most cancer-related deaths are linked to the occurrence of chemoresistance. Although chemoresistance can emerge through a multitude of mechanisms, chemoresistance and metastasis share a similar pathway, which is an epithelial-to-mesenchymal transition (EMT). Matrix metalloproteinases (MMPs), a class of zinc and calcium-chelated enzymes, are found to be key players in driving cancer migration and metastasis through EMT induction. The aim of this review is to discuss the regulatory roles and associated molecular mechanisms of specific MMPs in regulating chemoresistance, particularly EMT initiation and resistance to apoptosis. A brief presentation on their potential diagnostic and prognostic values was also deciphered. It also aimed to describe existing MMP inhibitors and the potential of utilizing other strategies to inhibit MMPs to reduce chemoresistance, such as upstream inhibition of MMP expressions and MMP-responsive nanomaterials to deliver drugs as well as epigenetic regulations. Hence, manipulation of MMP expression can be a powerful tool to aid in treating patients with chemo-resistant cancers. However, much still needs to be done to bring the solution from bench to bedside.

The Emerging Landscape of Long Non-Coding RNAs in Wilms Tumor

Long noncoding RNAs (LncRNAs) are transcripts of nucleic acid sequences with a length of more than 200 bp, which have only partial coding capabilities. Recent studies have shown that lncRNAs located in the nucleus or cytoplasm can be used as gene expression regulatory elements due to their important regulatory effects in a variety of biological processes. Wilms tumor (WT) is a common abdominal tumor in children whose pathogenesis remains unclear. In recent years, many specifically expressed lncRNAs have been found in WT, which affect the occurrence and development of WT. At the same time, lncRNAs may have the capacity to become novel biomarkers for the diagnosis and prognosis of WT. This article reviews related research progress on the relationship between lncRNAs and WT, to provide a new direction for clinical diagnosis and treatment of WT.

LncRNA UCA1 mediates Cetuximab resistance in Colorectal Cancer via the MiR-495 and HGF/c-MET Pathways

Background: Cetuximab is one of the most widely used monoclonal antibodies to treat patients with RAS/BRAF wild-type metastatic colorectal cancer (mCRC). Unfortunately, cetuximab resistance often occurs during targeted therapy. However, the underlying epigenetic mechanisms remain unclear. Our previous study demonstrated that the exosomal transfer of urothelial carcinoma-associated 1 (UCA1) confers cetuximab resistance to CRC cells. The goal of this study was to elucidate the detailed role of UCA1 in cetuximab resistance in CRC and the underlying molecular mechanism.

Methods:In vitro and in vivo functional studies were performed to assess the role of UCA1 in cetuximab resistance in CRC cell lines and xenograft models. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to examine UCA1 localization and expression. Bioinformatics analysis was performed to predict the potential mechanism of UCA1, which was further validated by the dual-luciferase reporter assay and the RNA immunoprecipitation (RIP) assay. Cells treated with indicators were subjected to Cell Counting Kit-8 (CCK-8) and western blotting to investigate the role of hepatocyte growth factor (HGF)/c-mesenchymal-epithelial transition (c-MET) signalling in UCA1-mediated cetuximab resistance.

Results: We showed that UCA1 decreased CRC cell sensitivity to cetuximab by suppressing apoptosis. Mechanistic studies revealed that UCA1 promoted cetuximab resistance by competitively binding miR-495 to facilitate HGF and c-MET expression in CRC cells. Moreover, HGF was shown to attenuate the cetuximab-induced inhibition of cell proliferation by activating the HGF/c-MET pathway in CRC cells.

Conclusion: We provide the first evidence of a UCA1-miR-495-HGF/c-MET regulatory network involved in cetuximab resistance in CRC. Therefore, UCA1 has potential as a predictor and therapeutic target for cetuximab resistance.

Identification of Combinations of Plasma lncRNAs and mRNAs as Potential Biomarkers for Precursor Lesions and Early Gastric Cancer

Patients with gastric cancer (GC) are usually first diagnosed at an advanced stage due to the absence of obvious symptoms at an early GC (EGC) stage. Therefore, it is necessary to identify an effective screening method to detect precursor lesions of GC (PLGC) and EGC to increase the 5-year survival rate of patients. Cell-free RNA, as a biomarker, has shown potential in early diagnosis, personalised treatment, and prognosis of cancer. In this study, six RNAs (CEBPA-AS1, INHBA-AS1, AK001058, UCA1, PPBP, and RGS18) were analysed via real-time quantitative polymerase chain reaction (RT-qPCR) using the plasma of patients with EGC and PLGC to identify diagnostic biomarkers. The receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic accuracy. Among the six RNAs, four lncRNAs (CEBPA-AS1, INHBA-AS1, AK001058, and UCA1) were upregulated and two mRNAs (PPBP and RGS18) were downregulated in the plasma of patients with PLGC and EGC. According to the findings of the ROC analysis, the four-RNA combination of INHBA-AS1, AK001058, UCA1, and RGS18 had the highest area under the curve (AUC) value for determining risk of GC in patients with PLGC and the six-RNA combination including CEBPA-AS1, INHBA-AS1, AK001058, UCA1, PPBP, and RGS18 had the highest AUC value for determining the risk of GC in patients with EGC. The results suggest the potential usefulness of noninvasive biomarkers for the molecular diagnosis of GC at earlier stages.

Antiviral peptides against SARS-CoV-2: therapeutic targets, mechanistic antiviral activity, and efficient delivery

The global pandemic of COVID-19 is a serious public health concern. Over 625 million confirmed cases and more than 6 million deaths have been recorded worldwide. Although several vaccines and antiviral medications have been developed, their efficacy is limited by the emerging new SARS-CoV-2 strains. Peptide-based therapeutics is a fast-growing class of new drugs and have unique advantages over large proteins and small molecules. Antiviral peptides (AVPs) are short polycationic antivirals with broad-spectrum effects, which have been shown to exert both prophylactic and therapeutic actions against reported coronaviruses. The potential therapeutic targets of AVPs are located either on the virus (e.g., E-protein and S-protein) to prohibit viral binding or host cells, particularly, those present on the cell surface (e.g., ACE2 and TMPRSS2). Despite AVPs having promising antiviral effects, their efficacy is limited by low bioavailability. Thus, nanoformulation is a prerequisite for prolonged bioavailability and efficient delivery. This review aimed to present an insight into the therapeutic AVP targets on both virus and host cells by discussing their antiviral activities and associated molecular mechanisms. Besides, it described the technique for discovering and developing possible AVPs based on their targets, as well as the significance of using nanotechnology for their efficient delivery against SARS-CoV-2.

Stabilization of UCA1 by N6-methyladenosine RNA methylation modification promotes colorectal cancer progression

Background

UCA1 is frequently upregulated in a variety of cancers, including CRC, and it can play an oncogenic role by various mechanisms. However, how UCA1 is regulated in cancer is largely unknown. In this study, we aimed to determine whether RNA methylation at N6-methyladenosine (m6A) can impact UCA1 expression in colorectal cancer (CRC).

Methods

qRT-PCR was performed to detect the level of UCA1 and IGF2BP2 in CRC samples. CRISPR/Cas9 was employed to knockout (KO) UCA1, METTL3 and WTAP in DLD-1 and HCT-116 cells, while rescue experiments were carried out to re-express METTL3 and WTAP in KO cells. Immunoprecipitation using m6A antibody was performed to determine the m6A modification of UCA1. In vivo pulldown assays using S1m tagging combined with site-direct mutagenesis was carried out to confirm the recognition of m6A-modified UCA1 by IGF2BP2. Cell viability was measured by MTT and colony formation assays. The expression of UCA1 and IGF2BP2 in TCGA CRC database was obtained from GEPIA (http://gepia.cancer-pku.cn).

Results

Our results revealed that IGF2BP2 serves as a reader for m6A modified UCA1 and that adenosine at 1038 of UCA1 is critical to the recognition by IGF2BP2. Importantly, we showed that m6A writers, METTL3 and WTAP positively regulate UCA1 expression. Mechanically, IGF2BP2 increases the stability of m6A-modified UCA1. Clinically, IGF2BP2 is upregulated in CRC tissues compared with normal tissues.

Conclusion

These results suggest that m6A modification is an important factor contributing to upregulation of UCA1 in CRC tissues.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02288-x.

Long Noncoding Competing Endogenous RNA Networks in Pancreatic Cancer

Pancreatic cancer (PC) is a highly malignant disease characterized by insidious onset, rapid progress, and poor therapeutic effects. The molecular mechanisms associated with PC initiation and progression are largely insufficient, hampering the exploitation of novel diagnostic biomarkers and development of efficient therapeutic strategies. Emerging evidence recently reveals that noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and microRNAs (miRNAs), extensively participate in PC pathogenesis. Specifically, lncRNAs can function as competing endogenous RNAs (ceRNAs), competitively sequestering miRNAs, therefore modulating the expression levels of their downstream target genes. Such complex lncRNA/miRNA/mRNA networks, namely, ceRNA networks, play crucial roles in the biological processes of PC by regulating cell growth and survival, epithelial-mesenchymal transition and metastasis, cancer stem cell maintenance, metabolism, autophagy, chemoresistance, and angiogenesis. In this review, the emerging knowledge on the lncRNA-associated ceRNA networks involved in PC initiation and progression will be summarized, and the potentials of the competitive crosstalk as diagnostic, prognostic, and therapeutic targets will be comprehensively discussed.

Meta-Analysis on the Improvement of Symptoms and Prognosis of Gastrointestinal Tumors Based on Medical Care and Exercise Intervention

Gastric cancer is a malignant tumor that originates from the epithelium of the gastric mucosa. It is the result of a combination of multiple factors, but the current research has not yet clarified its pathogenesis, so further research and exploration are needed. This article is mainly based on the meta-analysis of the improvement of gastrointestinal tumor-related symptoms and prognosis based on medical care and exercise intervention. The control group followed routine care after enrollment. In addition to routine care, patients in the intervention group exercised through assessment, formulation of exercise prescriptions, implementation of supervision, and adjustment. By viewing the subjects' physical examination reports, determine their blood routine, urine routine, blood lipids, blood sugar, liver and kidney function, and electrocardiogram examination. In this experiment, dual-contrast ultrasound in each T staging was greater than 0.8, indicating that the diagnostic method is very accurate in the preoperative diagnosis of gastric cancer T staging. The results show that exercise intervention can improve the pain of patients with gastrointestinal tumors after chemotherapy, relieve cancer-induced fatigue, and improve the quality of life.

Liquid Biopsy to Detect Minimal Residual Disease: Methodology and Impact

One reason why some patients experience recurrent disease after a curative-intent treatment might be the persistence of residual tumor cells, called minimal residual disease (MRD). MRD cannot be identified by standard radiological exams or clinical evaluation. Tumor-specific alterations found in the blood indirectly diagnose the presence of MRD. Liquid biopsies thus have the potential to detect MRD, allowing, among other things, the detection of circulating tumor DNA (ctDNA), circulating tumor cells (CTC), or tumor-specific microRNA. Although liquid biopsy is increasingly studied, several technical issues still limit its clinical applicability: low sensitivity, poor standardization or reproducibility, and lack of randomized trials demonstrating its clinical benefit. Being able to detect MRD could give clinicians a more comprehensive view of the risk of relapse of their patients and could select patients requiring treatment escalation with the goal of improving cancer survival. In this review, we are discussing the different methodologies used and investigated to detect MRD in solid cancers, their respective potentials and issues, and the clinical impacts that MRD detection will have on the management of cancer patients.

ELTD1 Promotes Gastric Cancer Cell Proliferation, Invasion and Epithelial-Mesenchymal Transition Through MAPK/ERK Signaling by Regulating CSK

Purpose

Patients with gastric cancer (GC) often die from metastasis. However, the exact molecular mechanism underlying GC metastasis is complicated and still remains elusive. Epidermal growth factor, latrophilin and seven-transmembrane domain-containing 1 (ELTD1), has been reported to be involved in cancer metastasis, but its role in GC is still missing.

Patients and Methods

We first analyzed the expression of ELTD1 in GC using public databases (TCGA, Oncomine, and GEO) and our clinical samples. The functions of ELTD1 in GC proliferation, invasion and metastasis were determined by in vitro and in vivo experiments. The functional mechanism of ETLD1 in GC was also investigated. Finally, the association between ELTD1 expression and the overall survival of GC patients was analyzed using public databases.

Results

ELTD1 is significantly upregulated in GC tissues. Knockdown of ELTD1 inhibits GC cell proliferation, migration and invasion in vitro as well as tumor growth and metastasis in vivo, while ELTD1 overexpression obtains opposite results. Moreover, ELTD1 could promote epithelial to mesenchymal transition (EMT) in GC. Mechanistically, ELTD1 exerts its tumor-promoting effect by activating MAPK/ERK signaling. Subsequent studies demonstrated that ELTD1 could interact with C-terminal Src kinase (CSK) and inhibit its expression, which finally lead to MAPK/ERK activation. Data from TGCA and GEO both revealed that GC patients with high ELTD1 expression had poorer prognosis and the combination of ELTD1 with CSK showed better predictive performance.

Conclusion

ELTD1 plays an oncogene role in GC through MAPK/ERK signaling via inhibiting CSK, which may be a useful prognostic predictor and potential therapeutic target for GC.