CD90 affects the biological behavior and energy metabolism level of gastric cancer cells by targeting the PI3K/AKT/HIF-1α signaling pathway

High Expression of THY1 in Intestinal Gastric Cancer as a Key Factor in Tumor Biology: A Poor Prognosis-Independent Marker Related to the Epithelial-Mesenchymal Transition Profile

Gastric cancer (GC) is an important cancer-related death worldwide. Among its histological subtypes, intestinal gastric cancer (IGC) is the most common. A previous work showed that increased expression of the THY1 gene was associated with poor overall survival in IGC. Furthermore, it was shown that IGC tumor cells with high expression of THY1 have a greater capacity for tumorigenesis and metastasis in vitro. This study aimed to identify molecular differences between IGC with high and low expression of THY1. Using a feature selection method, a group of 35 genes were found to be the most informative gene set for THY1high IGC tumors. Through a classification model, these genes differentiate THY1high from THY1low tumors with 100% of accuracy both in the test subset and the independent test set. Additionally, this group of 35 genes correctly clustered 100% of the samples. An extensive validation of this potential molecular signature in multiple cohorts successfully segregated between THY1high and THY1low IGC tumors (>95%), proving to be independent of the gene expression quantification methodology. These genes are involved in central processes to tumor biology, such as the epithelial-mesenchymal transition (EMT) and remodeling of the tumor tissue composition. Moreover, patients with THY1high IGC demonstrated poor survival and a more advanced clinicopathological staging. Our findings revealed a molecular signature for IGC with high THY1 expression. This signature showed EMT and remodeling of the tumor tissue composition potentially related to the biology of IGC. Altogether, our results indicate that THY1high IGC tumors are a particular subset of tumors with a specific molecular and prognosis profile.

Tumor microenvironment-induced tumor cell plasticity: relationship with hypoxic stress and impact on tumor resistance

The role of tumor interaction with stromal components during carcinogenesis is crucial for the design of efficient cancer treatment approaches. It is widely admitted that tumor hypoxic stress is associated with tumor aggressiveness and thus impacts susceptibility and resistance to different types of treatments. Notable biological processes that hypoxia functions in include its regulation of tumor heterogeneity and plasticity. While hypoxia has been reported as a major player in tumor survival and dissemination regulation, the significance of hypoxia inducible factors in cancer stem cell development remains poorly understood. Several reports indicate that the emergence of cancer stem cells in addition to their phenotype and function within a hypoxic tumor microenvironment impacts cancer progression. In this respect, evidence showed that cancer stem cells are key elements of intratumoral heterogeneity and more importantly are responsible for tumor relapse and escape to treatments. This paper briefly reviews our current knowledge of the interaction between tumor hypoxic stress and its role in stemness acquisition and maintenance. Our review extensively covers the influence of hypoxia on the formation and maintenance of cancer stem cells and discusses the potential of targeting hypoxia-induced alterations in the expression and function of the so far known stem cell markers in cancer therapy approaches. We believe that a better and integrated understanding of the effect of hypoxia on stemness during carcinogenesis might lead to new strategies for exploiting hypoxia-associated pathways and their targeting in the clinical setting in order to overcome resistance mechanisms. More importantly, at the present time, efforts are oriented towards the design of innovative therapeutical approaches that specifically target cancer stem cells.

Glycolysis in human cancers: Emphasis circRNA/glycolysis axis and nanoparticles in glycolysis regulation in cancer therapy

The metabolism of cancer has been an interesting hallmark and metabolic reprogramming, especially the change from oxidative phosphorylation in mitochondria to glucose metabolism known as glycolysis occurs in cancer. The molecular profile of glycolysis, related molecular pathways and enzymes involved in this mechanism such as hexokinase have been fully understood. The glycolysis inhibition can significantly decrease tumorigenesis. On the other hand, circRNAs are new emerging non-coding RNA (ncRNA) molecules with potential biological functions and aberrant expression in cancer cells which have received high attention in recent years. CircRNAs have a unique covalently closed loop structure which makes them highly stable and reliable biomarkers in cancer. CircRNAs are regulators of molecular mechanisms including glycolysis. The enzymes involved in the glycolysis mechanism such as hexokinase are regulated by circRNAs to modulate tumor progression. Induction of glycolysis by circRNAs can significantly increase proliferation rate of cancer cells given access to energy and enhance metastasis. CircRNAs regulating glycolysis can influence drug resistance in cancers because of theirimpact on malignancy of tumor cells upon glycolysis induction. TRIM44, CDCA3, SKA2 and ROCK1 are among the downstream targets of circRNAs in regulating glycolysis in cancer. Additionally, microRNAs are key regulators of glycolysis mechanism in cancer cells and can affect related molecular pathways and enzymes. CircRNAs sponge miRNAs to regulate glycolysis as a main upstream mediator. Moreover, nanoparticles have been emerged as new tools in tumorigenesis suppression and in addition to drug and gene delivery, then mediate cancer immunotherapy and can be used for vaccine development. The nanoparticles can delivery circRNAs in cancer therapy and they are promising candidates in regulation of glycolysis, its suppression and inhibition of related pathways such as HIF-1α. The stimuli-responsive nanoparticles and ligand-functionalized ones have been developed for selective targeting of glycolysis and cancer cells, and mediating carcinogenesis inhibition.

Combination of chemical profiling and network pharmacology analysis to investigate the potential mechanism of Li-Zhong-Xiao-Pi granules in the treatment of gastric precancerous lesions

Li-Zhong-Xiao-Pi granules (LZXP) are effective for treating gastric precancerous lesions (GPL) in traditional Chinese medicine. However, the active compounds of LZXP and their potential therapeutic mechanism in GPL remained unclarified. The purpose of this study is to investigate the chemical composition and potential targets of LZXP. Based on the accurate masses, ion fragments, and literature data, a total of 128 compounds were identified in the LZXP sample using ultra-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) in both positive and negative ion modes, and 28 of these compounds were exactly determined by comparison with authentic reference standards. Meanwhile, 11 typical components were quantified via UPLC during a 24 min period. The linearity, accuracy, stability and recovery of the method were all proven. Through the network pharmacological analysis, six chemicals (quercetin, 4'-hydroxywogonin, sinensetin, 5, 7, 8, 3', 4'-pentamethoxyflavanone, 8-gingerdione and quercetin) were identified as the active ingredients, and five LZXP targets (AKT1, CYP1B1, PTGS2, MMP9 and EGFR) were found to be the crucial molecules in the treatment of GPL. This study provides a systematic and applicable method for the rapid screening and identification of the chemical constituents from LZXP, and an effective understanding the mechanism of LZXP in the treatment of GPL.

Newly identified form of phenotypic plasticity of cancer: immunogenic mimicry

Cancer plasticity is now a recognized new hallmark of cancer which is due to disturbances of cell differentiation programs. It is manifested not only in various forms like the best-known epithelial-mesenchymal transition (EMT) but also in vasculogenic and megakaryocytic mimicries regulated by EMT-specific or less-specific transcription factors such as HIF1a or STAT1/2. Studies in the past decades provided ample data that cancer plasticity can be manifested also in the expression of a vast array of immune cell genes; best-known examples are PDL1/CD274, CD47, or IDO, and we termed it immunogenic mimicry (IGM). However, unlike other types of plasticities which are epigenetically regulated, expression of IGM genes are frequently due to gene amplifications. It is important that the majority of the IGM genes are regulated by interferons (IFNs) suggesting that their protein expressions are regulated by the immune microenvironment. Most of the IGM genes have been shown to be involved in immune escape of cancers broadening the repertoire of these mechanisms and offering novel targets for immunotherapeutics.

Programmed death ligand 1 signals in cancer cells

The paradigm of surface-expressed programmed death ligand 1 (PDL1) signalling to immune cell programmed death 1 (PD1) to inhibit antitumour immunity has helped to develop effective and revolutionary immunotherapies using antibodies blocking these cell-extrinsic interactions. The recent discovery of cancer cell-intrinsic PDL1 signals has broadened understanding of pathologic tumour PDL1 signal consequences that now includes control of tumour growth and survival pathways, stemness, immune effects, DNA damage responses and gene expression regulation. Many such effects are PD1-independent. These insights demonstrate that the prevailing cell-extrinsic PDL1 signalling paradigm is useful, but incomplete in important respects. This Perspective discusses historical and recent advances in understanding cancer cell-intrinsic PDL1 signals, mechanisms for signal controls and important immunopathologic consequences including resistance to cytotoxic agents, targeted small molecules and immunotherapies. Cancer cell-intrinsic PDL1 signals present novel drug discovery targets and also have potential as reliable treatment response biomarkers. Cancer cell-intrinsic PD1 signals and cell-intrinsic PDL1 signals in non-cancer cells are discussed briefly, as are PDL1 signals from soluble and vesicle-bound PDL1 and PDL1 isoforms. We conclude with suggestions for addressing the most pressing challenges and opportunities in this rapidly developing field.

CD90 is regulated by notch1 and hallmarks a more aggressive intrahepatic cholangiocarcinoma phenotype

BACKGROUND

Intrahepatic Cholangiocarcinoma (iCCA) is characterized by a strong stromal reaction playing a role in tumor progression. Thymus cell antigen 1 (THY1), also called Cluster of Differentiation 90 (CD90), is a key regulator of cell-cell and cell-matrix interaction. In iCCA, CD90 has been reported to be associated with a poor prognosis. In an iCCA PDX model, we recently found that CD90 was downregulated in mice treated with the Notch γ-secretase inhibitor Crenigacestat. The study aims to investigate the role of CD90 in relation to the NOTCH pathway.

METHODS

THY1/CD90 gene and protein expression was evaluated in human iCCA tissues and xenograft models by qRT-PCR, immunohistochemistry, and immunofluorescence. Notch1 inhibition was achieved by siRNA. THY1/CD90 functions were investigated in xenograft models built with HuCCT1 and KKU-M213 cell lines, engineered to overexpress or knockdown THY1, respectively.

RESULTS

CD90 co-localized with EPCAM, showing its epithelial origin. In vitro, NOTCH1 silencing triggered HES1 and THY1 down-regulation. RBPJ, a critical transcriptional regulator of NOTCH signaling, exhibited putative binding sites on the THY1 promoter and bound to the latter, implying CD90 as a downstream NOTCH pathway effector. In vivo, Crenigacestat suppressed iCCA growth and reduced CD90 expression in the PDX model. In the xenograft model, Crenigacestat inhibited tumor growth of HuCCT1 cells transfected to overexpress CD90 and KKU-M213 cells constitutively expressing high levels of CD90, while not affecting the growth of HuCCT1 control cells and KKU-M213 depleted of CD90. In an iCCA cohort, patients with higher expression levels of NOTCH1/HES1/THY1 displayed a significantly shorter survival.

CONCLUSIONS

iCCA patients with higher NOTCH1/HES1/THY1 expression have the worst prognosis, but they are more likely to benefit from Notch signaling inhibition. These findings represent the scientific rationale for testing NOTCH1 inhibitors in clinical trials, taking the first step toward precision medicine for iCCA.

Repressing phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma by microRNA-142-3p restrains the progression of hepatocellular carcinoma

This paper probes the mechanisms underlying miR-142-3p's modulation of hepatocellular carcinoma (HCC) invasion and apoptosis. Quantitative real-time PCR and Western blot monitored the miR-142-3p profile in HCC tissues and non-tumor tissues. The correlation between miR-142-3p expression and HCC patients' clinicopathological indicators was analyzed. miR-142-3p overexpression and knockdown models were established in HCC cell lines. Cell proliferation was gauged by the colony formation assay and BrdU staining. For measuring apoptosis, flow cytometry and Western blot were implemented. Transwell assay tested cell migration and invasion. miR-142-3p mimics or inhibitors were transfected in Huh7 and HCCLM3 cells. The targeting association between miR-142-3p and PIK3CG was predicted through bioinformatics and further verified by related experiments. The influence of PIK3CG overexpression on miR-142-3p's role in HCC was assayed. A xenografted tumor model was built in mice to validate miR-142-3p knockdown's influence on HCC in vivo. As a result, miR-142-3p exhibited a decreased profile in HCC tissues and cells. Overexpressing miR-142-3p accelerated apoptosis and suppressed the PI3K/AKT/HIF-1α signal. Knocking down miR-142-3p presented opposite effects. PIK3CG overexpression dampened the anti-tumor effect of miR-142-3p. miR-142-3p repressed HCC invasion and intensified apoptosis to restrain HCC by abating the PIK3CG-mediated PI3K/AKT/HIF-1α pathway.

LncRNA GAS6 antisense RNA 1 facilitates the tumorigenesis of clear cell renal cell carcinoma by regulating the AMP-activated protein kinase/mTOR signaling pathway

The role of GAS6 antisense RNA 1 (GAS6-AS1) in clear cell renal cell carcinoma (ccRCC) remains unclear. The aim of the present study was to investigate the role and molecular mechanisms of GAS6-AS1 in the progression of ccRCC. GAS6-AS1 was found to be upregulated in ccRCC tissues and cell lines, and patients with high GAS6-AS1 expression levels exhibited a poor prognosis. Small interfering (si)RNA GAS6-AS1 inhibited the activity, colony formation, invasiveness and glycolysis of OSRC-2 and SW839 cells, while GAS6-AS1 overexpression promoted these functions. Moreover, si-GAS6-AS1 increased the phosphorylation level of AMP-activated protein kinase (AMPK) and decreased that of mTOR, as well as decreasing proliferating cell nuclear antigen (PCNA), MMP-2 and hexokinase-2 (HK2) expression, which were reversed by inhibiting AMPK or mTOR. In addition, the silencing of GAS6-AS1 suppressed the growth of xenografted tumors and attenuated the expression of PCNA, MMP-2 and HK2 in tumor tissues. These findings conclude that GAS6-AS1 regulated the proliferation, invasiveness and glycolysis of ccRCC cells by regulating the AMPK/mTOR signaling pathway, and suggest that GAS6-AS1 may be a potential therapeutic target for ccRCC.