The relation between PI3K/AKT signalling pathway and cancer

SMARCC1 Suppresses Tumor Progression by Inhibiting the PI3K/AKT Signaling Pathway in Prostate Cancer

Background

SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin subfamily C member 1 (SMARCC1) protein is a potential tumor suppressor in various cancers. However, its role in prostate cancer (PCa) remains controversial. The aim of this study was to determine the biological function of SMARCC1 in PCa and explore the underlying regulatory mechanisms.

Methods

The expression of SMARCC1 was validated in PCa tissues by immunohistochemistry. Meanwhile, function experiments were used to evaluate the regulatory role on cell proliferation and metastasis in PCa cells with SMARCC1 depletion both in vitro and in vivo. The expression levels of relevant proteins were detected by Western blotting.

Results

Our finding showed that SMARCC1 was significantly downregulated in prostate adenocarcinoma, with a higher Gleason score (GS) than that in low GS. The decreased expression of SMARCC1 was significantly correlated with a higher GS and poor prognosis. Additionally, we found that silencing of SMARCC1 dramatically accelerated cell proliferation by promoting cell cycle progression and enhancing cell migration by inducing epithelial mesenchymal transition (EMT). Furthermore, depletion of SMARCC1 facilitated PCa xenograft growth and lung metastasis in murine models. Mechanistically, the loss of SMARCC1 activated the PI3K/AKT pathway in PCa cells.

Conclusion

SMARCC1 suppresses PCa cell proliferation and metastasis via the PI3K/AKT signaling pathway and is a novel therapeutic target.

A Signaling View into the Inflammatory Tumor Microenvironment

The development of tumors requires an initiator event, usually exposure to DNA damaging agents that cause genetic alterations such as gene mutations or chromosomal abnormalities, leading to deregulated cell proliferation. Although the mere stochastic accumulation of further mutations may cause tumor progression, it is now clear that an inflammatory microenvironment has a major tumor-promoting influence on initiated cells, in particular when a chronic inflammatory reaction already existed before the initiated tumor cell was formed. Moreover, inflammatory cells become mobilized in response to signals emanating from tumor cells. In both cases, the microenvironment provides signals that initiated tumor cells perceive by membrane receptors and transduce via downstream kinase cascades to modulate multiple cellular processes and respond with changes in cell gene expression, metabolism, and morphology. Cytokines, chemokines, and growth factors are examples of major signals secreted by immune cells, fibroblast, and endothelial cells and mediate an intricate cell-cell crosstalk in an inflammatory microenvironment, which contributes to increased cancer cell survival, phenotypic plasticity and adaptation to surrounding tissue conditions. Eventually, consequent changes in extracellular matrix stiffness and architecture, coupled with additional genetic alterations, further fortify the malignant progression of tumor cells, priming them for invasion and metastasis. Here, we provide an overview of the current knowledge on the composition of the inflammatory tumor microenvironment, with an emphasis on the major signals and signal-transducing events mediating different aspects of stromal cell-tumor cell communication that ultimately lead to malignant progression.

Central and peripheral emetic loci contribute to vomiting evoked by the Akt inhibitor MK-2206 in the least shrew model of emesis

Akt (protein kinase B) signaling is frequently activated in diverse cancers. Akt inhibitors such as perifosine and MK-2206 have been evaluated as potential cancer chemotherapeutics. Although both drugs are generally well tolerated, among their most common side-effects vomiting is a major concern. Here we investigated whether these Akt inhibitors evoke emesis in the least shrew model of vomiting. Indeed, both perifosine and MK-2206 induced vomiting with maximal efficacies of 90% at 50 mg/kg (i.p.) and 100% at 10 mg/kg (i.p.), respectively. MK-2206 (10 mg/kg, i.p.) increased c-Fos immunoreactivity both centrally in the shrew brainstem dorsal vagal complex (DVC) emetic nuclei, and peripherally in the jejunum. MK-2206 also evoked phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in both the DVC emetic nuclei and the enteric nervous system in the jejunum. The ERK1/2 inhibitor U0126 suppressed MK-2206-induced emesis dose-dependently. We then evaluated the suppressive efficacy of diverse antiemetics against MK-2206-evoked vomiting including antagonists/inhibitors of the: L-type Ca2+ channel (nifedipine at 2.5 mg/kg, subcutaneously (s.c.)); glycogen synthase kinase 3 (GSK-3) (AR-A014418 at 10 mg/kg and SB216763 at 0.25 mg/kg, i.p.); 5-hydroxytryptamine 5-HT3 receptor (palonosetron at 0.5 mg/kg, s.c.); substance P neurokinin NK1 receptor (netupitant at 10 mg/kg, i.p.) and dopamine D2/3 receptor (sulpride at 8 mg/kg, s.c.). All tested antagonists/blockers attenuated emetic parameters to varying degrees. In sum, this is the first study to demonstrate how pharmacological inhibition of Akt evokes vomiting via both central and peripheral mechanisms, a process which involves multiple emetic receptors.

Effects of 1800 MHz radiofrequency fields on signal transduction and antioxidant proteins in human A172 glioblastoma cells

PURPOSE

To assess the effects of 1800 MHz radiofrequency electromagnetic field (RF-EMF) exposure on the expression of signal transduction and antioxidant proteins in a human-derived A172 glioblastoma cell line.

MATERIALS AND METHODS

Adherent human-derived A172 glioblastoma cells (1.0 × 105 cells per 35 mm culture dish, containing 2 mL DMEM media) were exposed to 1800 MHz continuous-wave (CW) or GSM-modulated RF fields, in the presence or absence of serum for 5, 30 or 240 min at a specific absorption rate (SAR) of 0 (sham) or 2.0 W/kg. Concurrent negative (vehicle) and positive controls (1 µg/mL anisomycin) were included in each experiment. Cell lysates were collected immediately after exposure, stabilized by protease and phosphatase inhibitors in lysis buffer, then frozen and maintained at -80 °C until analysis. The relative expression levels of phosphorylated- and total-signal transduction proteins (CREB, JNK, NF-κB, ERK1/2, Akt, p70S6K, STAT3 and STAT5) and antioxidant proteins (SOD1, SOD2, CAT, TRX1, PRX2) were assessed using Milliplex magnetic bead array panels and a MagPix Multiplex imaging system.

RESULTS

In cells exposed to 1800 MHz continuous-wave RF-EMF with the presence of serum in the culture medium, CAT expression was statistically significantly decreased after a 30 min exposure, total JNK was decreased at both 30 and 240 min of exposure, STAT3 was decreased after 240 min of exposure and phosphorylated-CREB expression was decreased after 30 min of exposure. In cells exposed to 1800 MHz GSM-modulated RF-EMF in serum-free cultures, the expression level of total STAT5 was decreased after 30 and 240 min of exposure. These observed changes were detected sporadically across time-points, culture conditions and RF-EMF exposure conditions indicating the likelihood of false positive events. When cells were treated with anisomycin for 15 min as a positive control, dramatic increases in the expression of phosphorylated signaling proteins were observed in both serum-starved and serum-fed A172 cells, with larger fold change increases in the serum-free cultures. No statistically significant differences in the expression levels of SOD1, SOD2 or TRX1 were observed under any tested conditions after exposure to RF-EMF.

CONCLUSIONS

The current study found no consistent evidence of changes in the expression of antioxidant proteins (SOD1, SOD2, CAT or TRX2) or a variety of signal transductions proteins (CREB, JNK, NF-κB, ERK1/2, Akt, p70S6K, STAT3, STAT5) in a human-derived glioblastoma A172 cell line in response to exposure to 1800 MHz continuous-wave or GSM-modulated RF-EMF for 5, 30 or 240 min in either serum-free or serum-containing cultures.

Silencing LINC01116 suppresses the development of lung adenocarcinoma via the AKT signaling pathway

Background

A growing body of evidence has proven that long noncoding ribonucleic acids (lncRNAs) are important epigenetic regulators that play crucial parts in the pathogenesis of human cancers. Previous studies have shown that long intergenic nonprotein coding RNA 01116 (LINC01116) is a carcinogen in several carcinomas; however, its function in lung adenocarcinoma (LUAD) has not been clarified. Here, we aimed to investigate the role of LINC01116 in LUAD.

Methods

The relative expression levels of LINC01116 in LUAD cell lines and tissues were detected by quantitative reverse transcription polymerase chain reaction. A Kaplan–Meier survival analysis was performed using patient information from the Gene Expression Profiling Interactive Analysis (GEPIA) database. LUAD proliferation, invasion, migration, and apoptosis were measured by performing cell counting kit‐8, colony formation, transwell, wound healing, and flow cytometric assays. A xenograft animal experiment was performed to investigate the effect of LINC01116 in vivo. Protein kinase B (AKT) signaling pathway‐related protein expressions were tested by Western blot assay.

Results

LINC01116 expression was upregulated in LUAD cells and tissues. The loss‐of‐function experiments on LUAD cells revealed that silencing LINC01116 expression could decrease cell viability both in vitro and in vivo. Furthermore, silencing LINC01116 inhibited LUAD cell invasion and migration and induced cell apoptosis. Mechanically, silencing LINC01116 significantly decreased p‐AKT protein levels, and an AKT pathway stimulator could rescue the suppressive effects of small interfering LINC011116‐specific RNAs on LUAD development.

Conclusions

Our study demonstrated that silencing LINC01116 suppresses the development of LUAD via the AKT signaling pathway.

The impact of microRNAs on myeloid-derived suppressor cells in cancer

Inflammation promotes cancer development. To a large extent, this can be attributed to the recruitment of myeloid-derived suppressor cells (MDSCs) to tumors. These cells are known for establishing an immunosuppressive tumor microenvironment by suppressing T cell activities. However, MDSCs also promote metastasis and angiogenesis. Critically, as small non-coding RNAs that regulate gene expression, microRNAs (miRNAs) control MDSC activities. In this review, we discuss how miRNA networks regulate key MDSC signaling pathways, how they shape MDSC development, differentiation and activation, and how this impacts tumor development. By targeting the expression of miRNAs in MDSCs, we can alter their main signaling pathways. In turn, this can compromise their ability to promote multiple hallmarks of cancer. Therefore, this may represent a new powerful strategy for cancer immunotherapy.

Phosphatidylinositol 3-kinase (PI3K) inhibitors: a recent update on inhibitor design and clinical trials (2016-2020)

Introduction: The phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway plays a central role in regulating cell growth and proliferation and thus has been considered as effective anticancer drug targets. Many PI3K inhibitors have been developed and progressed to various stages of clinical trials, and some have been approved as anticancer treatment. In this review, we discuss the drug design and clinical development of PI3K inhibitors over the past 4 years. We review the selectivity and potency of 47 PI3K inhibitors. Structural determinants for increasing selectivity toward PI3K subtype-selectivity or mutant selectivity are discussed. Future research direction and current clinical development in combination therapy of inhibitors involved in PI3Ks are also discussed.Area covered: This review covers clinical trial reports and patent literature on PI3K inhibitors and their selectivity published between 2016 and 2020.Expert opinion: To PI3Kα mutants (E542K, E545K, and H1047R), it is highly desirable to design and develop mutant-specific PI3K inhibitors. It is also necessary to develop subtype-selective PI3Kα inhibitors to minimize toxicity. To reduce drug resistance and to improve efficacy, future studies should include combination therapy of PI3K inhibitors with existing anticancer drugs from different pathways.

Iridin Induces G2/M Phase Cell Cycle Arrest and Extrinsic Apoptotic Cell Death through PI3K/AKT Signaling Pathway in AGS Gastric Cancer Cells

Iridin is a natural flavonoid found in Belamcanda chinensis documented for its broad spectrum of biological activities like antioxidant, antitumor, and antiproliferative effects. In the present study, we have investigated the antitumor potential of iridin in AGS gastric cancer cells. Iridin treatment decreases AGS cell growth and promotes G2/M phase cell cycle arrest by attenuating the expression of Cdc25C, CDK1, and Cyclin B1 proteins. Iridin-treatment also triggered apoptotic cell death in AGS cells, which was verified by cleaved Caspase-3 (Cl- Caspase-3) and poly ADP-ribose polymerase (PARP) protein expression. Further apoptotic cell death was confirmed by increased apoptotic cell death fraction shown in allophycocyanin (APC)/Annexin V and propidium iodide staining. Iridin also increased the expression of extrinsic apoptotic pathway proteins like Fas, FasL, and cleaved Caspase-8 in AGS cells. On the contrary, iridin-treated AGS cells did not show variations in proteins related to an intrinsic apoptotic pathway such as Bax and Bcl-xL. Besides, Iridin showed inhibition of PI3K/AKT signaling pathways by downregulation of (p-PI3K, p-AKT) proteins in AGS cells. In conclusion, these data suggest that iridin has anticancer potential by inhibiting PI3K/AKT pathway. It could be a basis for further drug design in gastric cancer treatment.

Identification and Validation of SNP-Containing Genes With Prognostic Value in Gastric Cancer via Integrated Bioinformatics Analysis

Background

Gastric cancer is one of the most common malignancies worldwide. Although the diagnosis and treatment of this disease have substantially improved in recent years, the five-year survival rate of gastric cancer is still low due to local recurrence and distant metastasis. An in-depth study of the molecular pathogenesis of gastric cancer and related prognostic markers will help improve the quality of life and prognosis of patients with this disease. The purpose of this study was to identify and verify key SNPs in genes with prognostic value for gastric cancer.

Methods

SNP-related data from gastric cancer patients were obtained from The Cancer Genome Atlas (TCGA) database, and the functions and pathways of the mutated genes were analyzed using DAVID software. A protein-protein interaction (PPI) network was constructed using the STRING database and visualized by Cytoscape software, and molecular complex detection (MCODE) was used to screen the PPI network to extract important mutated genes. Ten hub genes were identified using cytoHubba, and the expression levels and the prognostic value of the central genes were determined by UALCAN and Kaplan-Meier Plotter. Finally, quantitative PCR and Western blotting were used to verify the expression of the hub genes in gastric cancer cells.

Results

From the database, 945 genes with mutations in more than 25 samples were identified. The PPI network had 360 nodes and 1616 edges. Finally, cytoHubba identified six key genes (TP53, HRAS, BRCA1, PIK3CA, AKT1, and SMARCA4), and their expression levels were closely related to the survival rate of gastric cancer patients.

Conclusion

Our results indicate that TP53, HRAS, BRCA1, PIK3CA, AKT1, and SMARCA4 may be key genes for the development and prognosis of gastric cancer. Our research provides an important bioinformatics foundation and related theoretical foundation for further exploring the molecular pathogenesis of gastric cancer and evaluating the prognosis of patients.

Lenvatinib induces anticancer activity in gallbladder cancer by targeting AKT

Gallbladder cancer (GBC) is characterized by poor prognosis, early metastasis, and high recurrence rates, which seriously threaten human health. The effect of lenvatinib, a widely used drug in anti-hepatocellular carcinoma in China, on GBC progress, as well as its underlying molecular mechanism, remains unclear. Therefore, the present study investigated the effect of lenvatinib on human GBC GBC-SD and NOZ cells and its underlying mechanisms. A series of experiments, including cell proliferation, clone formation, wound healing, and cell migration and invasion assays, as well as flow cytometry, were performed to investigate the anticancer effect of lenvatinib on GBC. Western blotting was used to detect alterations in protein expression of CKD2, CKD4, cyclin D1, caspase-9, matrix metalloproteinase (MMP)-2, cell migration-inducing protein (CEMIP) and phospho-AKT (p-AKT). In addition, the chemosensitivity of lenvatinib-treated GBC cells to gemcitabine (GEM) and whether the activation of phosphoinositide 3 kinase (PI3K)/AKT contributed to the chemoresistance were determined. Finally, the anticancer effect of lenvatinib in vivo was detected using a xenograft mouse model. These data showed that treatment with lenvatinib inhibited cell proliferation, colony formation ability, migration, induced apoptosis, regulated cell cycle and resulted in decreased resistance to GEM. Treatment with lenvatinib decreased the expression of MMP-2, CEMIP, CDK2, CDK4 and cyclin D1, and increased the expression of cleaved caspase-9, which was mediated by the inactivation of the PI3K/AKT pathway in vitro. In addition, lenvatinib inhibited autophagy in GBC-SD and NOZ cells. Besides, Lenvatinib suppressed GBC cell growth in vivo by targeting p-AKT. In combination, the present data indicated that lenvatinib plays a potential anticancer role in GBC by downregulating the expression of p-AKT.

MicroRNAs and angiogenesis: a new era for the management of colorectal cancer

MicroRNAs (miRNAs) are a class of small noncoding RNA molecules containing only 20–22 nucleotides. MiRNAs play a role in gene silencing and translation suppression by targeting and binding to mRNA. Proper control of miRNA expression is very important for maintaining a normal physiological environment because miRNAs can affect most cellular pathways, including cell cycle checkpoint, cell proliferation, and apoptosis pathways, and have a wide range of target genes. With these properties, miRNAs can modulate multiple signalling pathways involved in cancer development, such as cell proliferation, apoptosis, and migration pathways. MiRNAs that activate or inhibit the molecular pathway related to tumour angiogenesis are common topics of research. Angiogenesis promotes tumorigenesis and metastasis by providing oxygen and diffusible nutrients and releasing proangiogenic factors and is one of the hallmarks of tumour progression. CRC is one of the most common tumours, and metastasis has always been a difficult issue in its treatment. Although comprehensive treatments, such as surgery, radiotherapy, chemotherapy, and targeted therapy, have prolonged the survival of CRC patients, the overall response is not optimistic. Therefore, there is an urgent need to find new therapeutic targets to improve CRC treatment. In a series of recent reports, miRNAs have been shown to bidirectionally regulate angiogenesis in colorectal cancer. Many miRNAs can directly act on VEGF or inhibit angiogenesis through other pathways (HIF-1a, PI3K/AKT, etc.), while some miRNAs, specifically many exosomal miRNAs, are capable of promoting CRC angiogenesis. Understanding the mechanism of action of miRNAs in angiogenesis is of great significance for finding new targets for the treatment of tumour angiogenesis. Deciphering the exact role of specific miRNAs in angiogenesis is a challenge due to the high complexity of their actions. Here, we describe the latest advances in the understanding of miRNAs and their corresponding targets that play a role in CRC angiogenesis and discuss possible miRNA-based therapeutic strategies.

Curcumin Regulates Cancer Progression: Focus on ncRNAs and Molecular Signaling Pathways

Curcumin [(1E,6E) ‑1,7‑bis(4‑hydroxy‑3‑methoxyphenyl) hepta‑1,6‑diene‑3,5‑ dione] is a natural polyphenol derived from the rhizome of the turmeric plant Curcuma longa. Accumulated evidences have presented curcumin’s function in terms of anti-inflammatory, antioxidant properties, and especially anti-tumor activities. Studies demonstrated that curcumin could exert anti-tumor activity via multiple biological signaling pathways, such as PI3K/Akt, JAK/STAT, MAPK, Wnt/β-catenin, p53, NF-ĸB and apoptosis related signaling pathways. Moreover, Curcumin can inhibit tumor proliferation, angiogenesis, epithelial-mesenchymal transition (EMT), invasion and metastasis by regulating tumor related non-coding RNA (ncRNA) expression. In this review, we summarized the roles of curcumin in regulating signaling pathways and ncRNAs in different kinds of cancers. We also discussed the regulatory effect of curcumin through inhibiting carcinogenic miRNA and up regulating tumor suppressive miRNA. Furthermore, we aim to illustrate the cross regulatory relationship between ncRNA and signaling pathways, further to get a better understanding of the anti-tumor mechanism of curcumin, thus lay a theoretical foundation for the clinical application of curcumin in the future.

Ultrasound molecular imaging-guided tumor gene therapy through dual-targeted cationic microbubbles

The success of gene therapy depends largely on the development of gene vectors and effective gene delivery systems. It has been demonstrated that cationic microbubbles can be loaded with negatively charged plasmid DNA and thus improve gene transfection efficiency. In this study, we developed dual-targeting cationic microbubbles conjugated with iRGD peptides(Cyclo(Cys-Arg-Gly-Asp-Lys-Gly-Pro-Asp-Cys)) and CCR2 (chemokine (C-C motif) receptor 2) antibodies (MB_iRGD/CCR2) for ultrasound molecular imaging and targeted tumor gene therapy. The ultrasound molecular imaging experiments showed that there were significantly enhanced ultrasound molecular imaging signals in the tumor that received MB_iRGD/CCR2, compared with those that received MB_iRGD, MB_CCR2, or MB_control. As a therapy plasmid, pGPU6/GFP/Neo-shAKT2, carrying an expression cassette for the human AKT2 RNA interference sequence, was used. Our results demonstrated that MB_iRGD/CCR2 had a significantly higher gene transfection efficiency than MB_iRGD, MB_CCR2, or MB_control under ultrasound irradiation, resulting in much lower AKT2 protein expression and stronger tumor growth inhibition effects in vivo and in vitro. In conclusion, our study demonstrated a novel gene delivery system via MB_iRGD/CCR2 for ultrasound molecular-imaging-guided gene therapy of breast cancer.

The Spectrum, Tendency and Predictive Value of PIK3CA Mutation in Chinese Colorectal Cancer Patients

Background

PIK3CA is a high-frequency mutation gene in colorectal cancer, while its prognostic value remains unclear. This study evaluated the mutation tendency, spectrum, prognosis power and predictive power in cetuximab treatment of PIK3CA in Chinese CRC cohort.

Methods

The PIK3CA exon 9 and 20 status of 5763 CRC patients was detected with Sanger sequencing and a high-resolution melting test. Clinicopathological characteristics of 5733 patients were analyzed. Kaplan-Meier method and nomogram were used to evaluate the overall survival curve and disease recurrence, respectively.

Results

Fifty-eight types of mutations in 13.4% (771/5733) of the patients were detected. From 2014 to 2018, the mutation rate of PIK3CA increased from 11.0% to 13.5%. At stage IV, exon 20 mutated patients suffered shorter overall survival time than wild-type patients (multivariate COX regression analysis, HR = 2.72, 95% CIs = 1.47-5.09; p-value = 0.012). At stage III, PIK3CA mutated patients were more likely to relapse (multivariate Logistic regression analysis, exon 9: OR = 2.54, 95% CI = 1.34-4.73, p = 0.003; exon 20: OR = 3.89, 95% CI = 1.66-9.10, p = 0.002). The concordance index of the nomogram for predicting the recurrence risk of stage III patients was 0.685. After cetuximab treatment, the median PFS of PIK3CA exon 9 wild-type patients (n = 9) and mutant patients (n = 5) did not reach a significant difference (3.6 months vs. 2.3 months, Log-rank test, p-value = 0.513).

Conclusions

We found that PIK3CA mutation was an adverse predictive marker for the overall survival of stage IV patients and recurrence of stage III patients, respectively. Further more, we suggested that PIK3CA exon 9 mutations are not negative predictors of cetuximab treatment in KRAS, NRAS, and BRAF wild-type mCRC patients.

Anti-Lung Cancer Targets of Radix Paeoniae Rubra and Biological Molecular Mechanism: Network Pharmacological Analyses and Experimental Validation

Objective

To systematically explore the pharmacological mechanism of Radix Paeoniae Rubra (RPR) against lung cancer (LC).

Methods

A network pharmacology approach, which involves active ingredients and target forecast, network construction, gene ontology and pathway enrichment, was employed in this research. In addition, the effect of Baicalein (BAI) in RPR on A549 cells was researched in vitro and in vivo.

Results

A total of 159 targets of the 29 active components in RPR were procured by pharmacokinetic parameters. The network analysis showed that β-sitosterol, baicalein, (+)-catechin, ellagic acid, stigmasterol, (2R, 3R)-4-methoxyl-distylin were the main ingredients and JUN, VEGFA, BCL2 were the hub targets of RPR in the treatment of LC. The functional enrichment analysis showed that RPR likely was useful to LC by regulating numerous pathways including Pathways in cancer, MAPK signaling pathway and so on. MTT results showed that 100μM, 200μM, 400μM of BAI had a time and dose-dependent inhibitory effect on A549 cells proliferation; Wound healing and transwell assays showed that 100μM, 200μM, 400μM of BAI could significantly restrain the migration and invasion of A549 cells; Flow cytometry assay results showed that 100μM, 200μM, 400μM of BAI could induce apoptosis of A549 cells. In vivo, BAI (50, 100 mg/kg) significantly inhibited tumor growth and promoted apoptosis of tumor cells compared with the control group.

Conclusion

BAI in RPR may exert anti-tumor effects by inhibiting the proliferation, migration and invasion of LC cells, and inducing the apoptosis of LC cells.

New Therapeutic Opportunities for the Treatment of Squamous Cell Carcinomas: A Focus on Novel Driver Kinases

Squamous cell carcinomas of the lung, head and neck, esophagus, and cervix account for more than two million cases of cancer per year worldwide with very few targetable therapies available and minimal clinical improvement in the past three decades. Although these carcinomas are differentiated anatomically, their genetic landscape shares numerous common genetic alterations. Amplification of the third chromosome's distal portion (3q) is a distinguishing genetic alteration in most of these carcinomas and leads to copy-number gain and amplification of numerous oncogenic proteins. This area of the chromosome harbors known oncogenes involved in squamous cell fate decisions and differentiation, including TP63, SOX2, ECT2, and PIK3CA. Furthermore, novel targetable oncogenic kinases within this amplicon include PRKCI, PAK2, MAP3K13, and TNIK. TCGA analysis of these genes identified amplification in more than 20% of clinical squamous cell carcinoma samples, correlating with a significant decrease in overall patient survival. Alteration of these genes frequently co-occurs and is dependent on 3q-chromosome amplification. The dependency of cancer cells on these amplified kinases provides a route toward personalized medicine in squamous cell carcinoma patients through development of small-molecules targeting these kinases.

Systematic Identification of circRNA-miRNA-mRNA Regulatory Network in Esophageal Squamous Cell Carcinoma

Background

Circular RNAs (circRNAs) are described as endogenous non-coding RNAs that have been reported to play important roles in the development and progression of cancers. This study aimed to reveal the circRNA-related regulatory mechanism in esophageal squamous cell carcinoma (ESCC).

Methods

A genome-wide circRNA microarray assay was performed to profile the expression of circRNAs in the blood of preoperative ESCC patients and healthy controls. A systematic method of data mining was performed to identify the differentially expressed miRNAs (DEmiRs) and differentially expressed genes (DEGs) based on the metaMA and RankProd analysis. Bioinformatics analyses and multiple tools were employed to construct the potential circRNA–miRNA–mRNA regulatory network.

Results

Thirty-three differentially expressed circRNAs were identified in the ESCC blood, including 31 downregulated and two upregulated circRNAs in the blood of ESCC patients compared with the healthy controls. Twenty-three DEmiRs and 2,220 DEGs were obtained by the integration of microarray datasets. An ESCC-associated circRNA–miRNA–mRNA network was constructed based on 31 circRNAs, 3 DEmiRs, and 190 DEGs. Enrichment analyses indicated that the DEGs were associated with a series of biological processes and cancer-related pathways. The protein–protein interaction (PPI) network was generated by the 190 DEGs, with 10 hub genes verified in the network. Subsequently, a sub-network was established for ESCC, which included 29 circRNAs, 2 miRNAs, and 10 hub genes.

Conclusion

Our study provided a novel clue to help understand the circRNA–miRNA–mRNA regulatory mechanism, highlighting the potential roles of circRNAs in the pathogenesis and development of ESCC.

The Controversial Role of Autophagy in Ewing Sarcoma Pathogenesis-Current Treatment Options

Ewing Sarcoma (ES) is a rare, aggressive, and highly metastasizing cancer in children and young adults. Most ES cases carry the fusion of the Ewing Sarcoma Breakpoint Region 1 (EWSR1) and FLI1 (Friend leukemia virus integration site 1) genes, leading to an EWS-FLI1 fused protein, which is associated with autophagy, a homeostatic and catabolic mechanism under normal and pathological conditions. Following such interesting and controversial data regarding autophagy in ES, many clinical trials using modulators of autophagy are now underway in this field. In the present review, we summarize current data and clinical trials that associate autophagy with ES. In vitro studies highlight the controversial role of autophagy as a tumor promoter or a tumor suppressor mechanism in ES. Clinical and in vitro studies on ES, together with the autophagy modulators, suggest that caution should be adopted in the application of autophagy as a therapeutic target. Monitoring and targeting autophagy in every ES patient could eliminate the need for targeting multiple pathways in order to achieve the maximum beneficial effect. Future studies are required to focus on which ES patients are affected by autophagy modulators in order to provide novel and more efficient therapeutic protocols for patients with ES based on the current autophagy status of the tumors.

The HOTAIR lncRNA: A remarkable oncogenic promoter in human cancer metastasis

Long non-coding RNA (lncRNA) is a new type of non-coding RNA that has an important regulatory influence on several human diseases, including cancer metastasis. HOX antisense intergenic RNA (HOTAIR), a newly discovered lncRNA, has an important effect on tumour proliferation, migration and metastasis. HOTAIR regulates cell proliferation, changes gene expression, and promotes tumour cell invasion and migration. However, its molecular mechanism of action remains unknown. The present review summarizes the molecular mechanism and role of HOTAIR in tumour invasion and metastasis, discusses the association between HOTAIR and tumour metastasis through different pathways, such as the transforming growth factor β, Wnt/β-catenin, PI3K/AKT/MAPK and vascular endothelial growth factor pathways, emphasizes the function of HOTAIR in human malignant tumour metastasis and provides a foundation for its application in the diagnosis, prognosis and medical treatment of various tumours.

MPP7 promotes the migration and invasion of breast cancer cells via EGFR/AKT signaling

Metastasis is a major cause of breast cancer death. MPP7 is a cell polarity controller highly linked to cell migration; however, the function of MPP7 in breast cancer remains unknown. In this study, we reported that MPP7 expression was upregulated in breast cancer tissues and high MPP7 expression predicted poor survival in patients with breast cancer. Ectopic expression of MPP7 markedly enhanced the migration and invasion in breast cancer cells. In contrast, depletion of MPP7 resulted in impaired cell mobility and metastasis. Moreover, we demonstrated that MPP7 exerted its promotional effect via modulation of EMT and activation of the EGFR/AKT cascade. Our study reveals an oncogenic role of MPP7 in breast cancer and suggests that MPP7 may serve as a potential target for exploring novel therapeutic strategies against breast cancer metastasis.

LncRNA DNAJC3-AS1 Regulates Fatty Acid Synthase via the EGFR Pathway to Promote the Progression of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide. Recent studies have shown that long non-coding RNAs (lncRNAs) are involved in tumorigenesis and the development of CRC. By constructing a differential lncRNA expression profile, we screened gene chips and found that DNAJC3-AS1 was highly expressed in CRC tissues and was associated with poor prognosis in patients with CRC. Further, we proved through assays such as wound healing, colony formation, and Cell Counting Kit-8 (CCK8) that interfering with DNAJC3-AS1 could reduce the proliferation, migration, and invasion of CRC cells. Mechanically, we found that DNAJC3-AS1 regulates fatty acid synthase to promote the progression of CRC via the epidermal growth factor receptor/phosphatidylinositol 3-kinase/protein kinase B/nuclear factor κB signaling pathway. Therefore, DNAJC3-AS1 may be a new target for the diagnosis and therapy of CRC.

Silencing of Long Non-coding RNA ENST00000606790.1 Inhibits the Malignant Behaviors of Papillary Thyroid Carcinoma through the PI3K/AKT Pathway

PURPOSE

This study aimed to investigate the role and mechanism of lncRNA ENST00000606790.1 (ENST) in promoting the progression of papillary thyroid carcinoma (PTC).

METHODS

The expression of ENST in human PTC and normal para-cancerous thyroid (NPTC) tissues or cell lines was determined by RT-qPCR. Cell growth was determined by CCK8 assay. Cell colony formation was determined by cell colony formation assay. Cell cycle analysis was performed by staining cells with PI (Propidium Iodide). Cell invasion was assessed by transwell assay. Protein expression was examined by western-blot. siRNA was constructed to inhibit the expression of ENST. 740-Y-P was used to activate PI3K. The correlation between ENST expression and clinical outcomes was analyzed.

RESULTS

ENST was significantly up-regulated in PTC tissues or PTC cell lines (PTC and IHH4 cell lines), compared to NPTC tissues or normal cell lines, respectively. High expression of ENST was strongly correlated to lymph node metastasis and tumor size at diagnosis. Silencing of ENST significantly inhibited cell growth and colony formation, arrested the cell cycle at G2/M phase, upregulated the expression of CHK1, downregulated the expression of CDC25C, and inhibited cell invasion. Silencing of ENST significantly down-regulated the expression of PI3K, p-PI3K, AKT, and p-AKT in IHH4 cells. Furthermore, treatment with the PI3K activator  740-Y-P partially abolished the effect of silencing of ENST on PTC cells.

CONCLUSIONS

Overall, our results demonstrated that ENST can promote PTC progression by activating the PI3K/AKT signaling pathway, suggesting that ENST can serve as a potential biomarker and new therapeutic target for patients with PTC.

GSG2 Promotes Development and Predicts Poor Prognosis of Ovarian Cancer

Purpose

Ovarian cancer is one of the most common malignant tumors in gynecology, whose treatment was seriously limited by the unclear understanding of molecular mechanism in disease development. GSG2, also known as Haspin, is a novel molecule found to be involved in human cancers.

Materials and Methods

In this study, immunohistochemical analysis was used to detect GSG2 expression in ovarian cancer tissues and corresponding normal tissues. Statistical analysis was performed to construct relationship between GSG2 and tumor characteristics as well as prognosis. Ovarian cell model with GSG2 knockdown was constructed through lentivirus-mediated transfection of shRNA, which was used in MTT assay, colony formation assay and flow cytometry for investigating the role of GSG2 in ovarian cancer. A human apoptosis antibody array was used to identify potential downstream apoptosis-related proteins of GSG2.

Results

The results demonstrated the upregulation of GSG2 in ovarian cancer, whose expression was positively related to tumor grade and AJCC stage, and negatively correlated with patients’ prognosis. Moreover, knockdown of GSG2 inhibited ovarian cancer development through suppressing cell growth and inducing cell apoptosis. Further exploration revealed that a variety of apoptosis-related and PI3K signaling pathway-related proteins may be implicated in the GSG2 induced regulation of ovarian cancer.

Conclusion

In summary, it was illustrated that GSG2 was involved in the development of ovarian cancer, which has the potential to become therapeutic target and prognostic indicator in ovarian cancer treatment.

Inhibition of PI3K/AKT signaling via ROS regulation is involved in Rhein-induced apoptosis and enhancement of oxaliplatin sensitivity in pancreatic cancer cells

Several natural products have been demonstrated to both enhance the anti-tumor efficacy and alleviate the side effects of conventional chemotherapy drugs. Rhein, a main constituent of the Chinese herb rhubarb, has been shown to induce apoptosis in various cancer types. However, the exact pharmacological mechanisms controlling the influence of Rhein on chemotherapy drug effects in pancreatic cancer (PC) remain largely undefined. In this study, we found that Rhein inhibited the growth and proliferation of PC cells through G1 phase cell cycle arrest. Moreover, Rhein induced caspase-dependent mitochondrial apoptosis of PC cells through inactivation of the PI3K/AKT pathway. Combination treatment of Rhein and oxaliplatin synergistically enhanced apoptosis of PC cells through increased generation of intracellular reactive oxygen species (ROS) and inactivation of the PI3K/AKT pathway. Pre-treatment with the ROS scavenger N-acetyl-L-cysteine attenuated the combined treatment-induced apoptosis and restored the level of phosphorylated AKT, indicating that ROS is an upstream regulator of the PI3K/AKT pathway. The combination therapy also exhibited stronger anti-tumor effects compared with single drug treatments in vivo. Taken together, these data demonstrate that Rhein can induce apoptosis and enhance the oxaliplatin sensitivity of PC cells, suggesting that Rhein may be an effective strategy to overcome drug resistance in the chemotherapeutic treatment of PC.

Transcriptional Regulation of PIK3CD and PIKFYVE in T-Cell Acute Lymphoblastic Leukemia by IKAROS and Protein Kinase CK2

IKAROS, encoded by the IKZF1 gene, is a DNA-binding protein that functions as a tumor suppressor in T cell acute lymphoblastic leukemia (T-ALL). Recent studies have identified IKAROS’s novel function in the epigenetic regulation of gene expression in T-ALL and uncovered many genes that are likely to be directly regulated by IKAROS. Here, we report the transcriptional regulation of two genes, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD) and phosphoinositide kinase, FYVE-type zinc finger containing (PIKFYVE), by IKAROS in T-ALL. PIK3CD encodes the protein p110δ subunit of phosphoinositide 3-kinase (PI3K). The PI3K/AKT pathway is frequently dysregulated in cancers, including T-ALL. IKAROS binds to the promoter regions of PIK3CD and PIKFYVE and reduces their transcription in primary T-ALL. Functional analysis demonstrates that IKAROS functions as a transcriptional repressor of both PIK3CD and PIKFYVE. Protein kinase CK2 (CK2) is a pro-oncogenic kinase that is overexpressed in T-ALL. CK2 phosphorylates IKAROS, impairs IKAROS’s DNA-binding ability, and functions as a repressor of PIK3CD and PIKFYVE. CK2 inhibition results in increased IKAROS binding to the promoters of PIK3CD and PIKFYVE and the transcriptional repression of both these genes. Overall, the presented data demonstrate for the first time that in T-ALL, CK2 hyperactivity contributes to PI3K signaling pathway upregulation, at least in part, through impaired IKAROS transcriptional regulation of PIK3CD and PIKFYVE. Targeting CK2 restores IKAROS’s regulatory effects on the PI3K oncogenic signaling pathway.

JMJD8 Promotes Malignant Progression of Lung Cancer by Maintaining EGFR Stability and EGFR/PI3K/AKT Pathway Activation

JMJD8 is a JmjC domain-containing protein that has not been widely examined, despite its potential role in malignant tumor development. The underlying biological functions and molecular mechanisms of JMJD8 in non-small-cell lung cancer (NSCLC) remain unclear. Herein, we explored the relationship between JMJD8 and the activation of malignancy pathways in NSCLC. Immunohistochemical analyses revealed that high JMJD8 expression significantly correlated with cell differentiation and advanced TNM stages of NSCLC. The overexpression of JMJD8 promoted cell proliferation and invasion in vitro. Upon JMJD8 knockdown in lung cancer cell lines, cyclin B1, RhoA, RhoC, MMP9, and N-cadherin were down-regulated, and p21 and E-cadherin were conversely up-regulated. Key factors in the PI3K/AKT signaling pathway, such as p‑AKT, showed clear decreases in expression; additionally, the expression of epidermal growth factor receptor (EGFR), which functions upstream of PI3K, was altered. Co-immunoprecipitation experiments indicated that JMJD8 interacts with EGFR, and JMJD8 knockdown accelerated EGFR degradation. Our results suggested that JMJD8 functions as an oncogenic regulator in NSCLC. We found that JMJD8 promotes carcinogenic activity in NSCLC cells by facilitating EGFR stability, thereby activating the downstream PI3K/AKT signaling pathway. JMJD8 shows potential as a prognostic marker for lung cancer patients, providing a new target for therapeutic strategies.

The Potential Role of N6-Methyladenosine (m6A) Demethylase Fat Mass and Obesity-Associated Gene (FTO) in Human Cancers

N6-methyladenosine (m6A) demethylase fat mass and obesity-associated gene(FTO), previously recognized to be related with obesity and diabetes, was gradually discovered to be dysregulated in multiple cancers and plays an oncogenic or tumor-suppressive role. However, the specific expression and pro- or anti-cancer role of FTO in various cancers remained controversial. In this review, through summarizing the available literature, we found that FTO single nucleotide polymorphisms (SNPs) were closely related with cancer risk. Additionally, the dysregulation of FTO was implicated in multiple biological processes, such as cancer cell apoptosis, proliferation, migration, invasion, metastasis, cell-cycle, differentiation, stem cell self-renewal and so on. These modulations mostly relied on the communications between FTO and specific signaling pathways, including PI3K/AKT, MAPK and mTOR signaling pathways. Furthermore, FTO had great potential for clinical application by serving as a prognostic biomarker.

Long Non-Coding RNA AC118344.1 Promotes Gastric Cancer Cell Proliferation, Invasion, and Metastasis via AKT2 and Its Downstream Molecules HK2 and MMP2

Background

Gastric cancer (GC) is a highly occurring cancer with poor prognosis. Reports indicate that long non-coding RNA (LncRNA) potentially regulates tumor progression. Herein, we aim to explore the effect of LncRNA AC118344.1 on the progression of gastric cancer.

Methods

Overexpression and knockout experiments were used to clarify the potential molecular signaling mechanisms induced by AC118344.1. CCK-8, transwell and in vivo metastasis assay were used to detect the function of AC118344.1 in AGS and SGC-7901 cells. Additionally, shRNA silencing techniques, qRT-PCR and Western blot assay were used to explore the relationship between AC118344.1, AKT2, and its downstream molecules.

Results

Upregulating the expression of AC118344.1 induces cell proliferation, invasion in vitro, and lung metastasis in vivo whereas downregulating the expression of AC118344.1 inhibits these effects. Besides, silencing the expression of AC118344.1 downregulated the expression of AKT2 in both the two cells. On the other hand, silencing the expression of AKT2 by shRNA was unable to downregulate the expression of AC118344.1 in both the gastric cancer cells. Also, AC118344.1 regulated AKT2 via its downstream molecules including HK2 and MMP2.

Conclusion

AC118344.1 promotes gastric cancer cell proliferation and invasion and lung metastasis in nude mice by upregulating the expression of AKT2 and its downstream molecules (HK2 and MMP2). Therefore, our findings provide a novel mechanism of the AC118344.1-AKT2-HK2/MMP2 axis in regulating the development of gastric cancer cells.

ZNF703 promotes tumor progression in ovarian cancer by interacting with HE4 and epigenetically regulating PEA15

Background

It is known that the transcription factor zinc finger protein 703 (ZNF703) plays an important role in physiological functions and the occurrence and development of various tumors. However, the role and mechanism of ZNF703 in ovarian cancer are unclear.

Materials and methods

Immunohistochemistry was used to analyze the expression of ZNF703 in ovarian cancer patients and to assess the effect of ZNF703 expression on the survival and prognosis of ovarian cancer patients. ZNF703 overexpression and suppression expression experiments were used to evaluate the effect of ZNF703 on malignant biological behavior of ovarian cancer cells in vitro. Detecting the interaction between HE4 and ZNF703 by immunofluorescence colocalization and coprecipitation, and nuclear translocation. Chromatin immunoprecipitation-sequencing (ChIP-Seq), dual luciferase reporter assay, ChIP-PCR, in vivo model were applied to study the molecular mechanism of ZNF703 affecting the development of ovarian cancer.

Results

ZNF703 was highly expressed in ovarian cancer tissues, and its expression level is related to the prognosis of ovarian cancer patients. In vivo and in vitro experiments confirmed that ZNF703 overexpression/inhibition expression will promoted/inhibited the malignant biological behavior of ovarian cancer. Mechanically, ZNF703 interacted with HE4, and HE4 promoted nuclear translocation of ZNF703. ChIP-Seq identified multiple regulatory targets of ZNF703, of which ZNF703 directly binds to the enhancer region of PEA15 to promote the transcription of PEA15 and thereby promoted the proliferation of cancer cells.

Conclusion

The results showed that ZNF703 as an oncogene played an important role in the epigenetic modification of ovarian cancer proliferation, and suggested that ZNF703 as a transcription factor may become a prognostic factor and a potential therapeutic target for ovarian cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-020-01770-0.

Brusatol reverses lipopolysaccharide-induced epithelial-mesenchymal transformation and induces apoptosis through PI3K/Akt/NF-кB pathway in human gastric cancer SGC-7901 cells

Brusatol is a butyrolactone compound isolated from traditional Chinese medicine Brucea javanica. It has been reported to possess strong cytotoxicity against various cancer cells, thus showing its potential as an anticancer drug. Besides, lipopolysaccharide (LPS) plays a central role in the tumor microenvironment, while epithelial-mesenchymal transformation (EMT), a biological process by which epithelial cells are transformed into mesenchymal phenotypic cells through specific procedures, participates in chronic inflammation and tumor metastasis. This study aimed to investigate the inhibition of LPS-induced tumor cell invasion and metastasis and the molecular mechanism of apoptosis induced by brusatol in human gastric cancer SGC-7901 cells. Cell viability, cell migration and invasion ability, inflammatory factor release, and protein expression were detected using methyl thiazolyl tetrazolium assays, transwell assays, ELISA kit, and Western blot analysis, respectively. The change of EMT marker protein vimentin was assessed using immunofluorescence, while the apoptosis rate was measured using flow cytometry. In summary, brusatol inhibited LPS-induced EMT via the deactivation of the PI3K/Akt/NF-кB signaling pathway. This provides a useful new theoretical basis for the treatment of gastric cancer in the future.

Non-Coding RNAs: Uncharted Mediators of Thyroid Cancer Pathogenesis

Thyroid cancer is the most prevalent malignancy of the endocrine system and the ninth most common cancer globally. Despite the advances in the management of thyroid cancer, there are critical issues with the diagnosis and treatment of thyroid cancer that result in the poor overall survival of undifferentiated and metastatic thyroid cancer patients. Recent studies have revealed the role of different non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) that are dysregulated during thyroid cancer development or the acquisition of resistance to therapeutics, and may play key roles in treatment failure and poor prognosis of the thyroid cancer patients. Here, we systematically review the emerging roles and molecular mechanisms of ncRNAs that regulate thyroid tumorigenesis and drug response. We then propose the potential clinical implications of ncRNAs as novel diagnostic and prognostic biomarkers for thyroid cancer.

Emerging roles of long noncoding RNAs in cholangiocarcinoma: Advances and challenges

Cholangiocarcinoma (CCA), a cancer with a relatively low incidence rate, is usually associated with poor prognosis. Current modalities for the diagnosis and treatment of CCA patients are still far from satisfactory. In recent years, numerous long noncoding RNAs (lncRNAs) have been identified as crucial players in the development of various cancers, including CCA. Abnormally expressed lncRNAs in CCA, regulated by some upstream molecules, significantly influence the biological behavior of tumor cells and are involved in tumor development through various mechanisms, including interactions with functional proteins, participation in competing for endogenous RNA (ceRNA) regulatory networks, activation of cancer‐related signaling pathways and epigenetic modification of gene expression. Furthermore, several lncRNAs are closely associated with the clinicopathological features of CCA patients, and are promising biomarkers for diagnosing and prognostication of CCA. Some of these lncRNAs play an important role in chemotherapy drug resistance. In addition, lncRNAs have also been shown to be involved in the inflammation microenvironment of CCA and malignant outcome of CCA risk factors, such as cholestatic liver diseases. In view of the difficulty of diagnosing CCA, more attention should be paid to detectable lncRNAs in the serum or bile. This review summarizes the recent knowledge on lncRNAs in CCA and provides a new outlook on the molecular mechanisms of CCA development from the perspective of lncRNAs. Moreover, we also discussed the limitations of the current studies and differential expression of lncRNAs in different types of CCA.

Identification of MSC-AS1, a novel lncRNA for the diagnosis of laryngeal cancer

PURPOSE

Our study was aimed to identify potential lncRNAs related to laryngeal cancer (LC) and explore their potential regulatory mechanisms.

METHODS

RNA sequencing data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were used to identify differentially expressed genes (DEGs). Receiver operating characteristic (ROC) curve analysis was performed to analyze the sensitivity and specificity of differentially expressed lncRNAs (DElncRNAs) as biomarkers. Weighted gene co-expression network analysis (WGCNA) was applied to identify co-expressed DElncRNAs and differentially expressed mRNAs (DEmRNAs) associated with clinical indicators. We performed functional enrichment analysis on target genes and constructed a lncRNA-miRNA-mRNA ceRNA network. The expression of lncRNA and mRNAs in ceRNA network were validated via RT-qPCR.

RESULTS

By differential expression analyzing TCGA and GEO data, 6 up-regulated DElncRNAs were consistently identified, and their predictive performance were suggested to be considerable via ROC curve. 1998 DEmRNAs and 6 lncRNAs were involved in the construction of WGCNA network, in which the MEblue module was positively correlated with clinical stage. Functional enrichment analysis of this module suggested that the functions of DEmRNAs were closely involved in PI3K/Akt pathway. A ceRNA network composed of MSC-AS1, miR-429, COL4A1 and ITGAV was constructed. It was verified by RT-qPCR that the lncRNA and mRNAs in the ceRNA network were highly expressed in multiple LC tissues.

CONCLUSIONS

This study identified lncRNA MSC-AS1 as a potential biomarker of LC. Besides, we constructed a ceRNA network, which provides a basis for the research of ceRNA in LC.

Topoisomerase II alpha promotes gallbladder cancer proliferation and metastasis through activating phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway

BACKGROUND

Topoisomerase II alpha (TOP2A) has been reported to play a crucial role in the tumorigenesis of various cancer types. However, the biological role of TOP2A in gallbladder cancer (GBC) remains unknown. The current study aimed to explore the function and potential mechanism of TOP2A in GBC.

METHODS

Based on Gene Expression Profiling Interactive Analysis data, we found TOP2A was significantly up-regulated in GBC tissues and resulting in shorter overall survival. Quantitative real-time polymerase chain reaction and immunohistochemistry were conducted to detect the expression of TOP2A in 45 pairs of GBC tissues and adjacent non-tumor tissues. In vitro, cell proliferation, migration, and invasion ability were examined by cell counting kit-8 and transwell assay, respectively. Epithelial-mesenchymal transition (EMT) related and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway-related markers were measured by Western blotting. Xenograft model assay was performed to evaluate the effect of TOP2A in vivo.

RESULTS

TOP2A was found up-regulated in GBC (tumor vs. normal, 12.62 vs. 0.34) and correlated with the late tumor node metastasis stage (P = 0.0032), present of lymph node metastasis (P = 0.0273), and poor prognosis in GBC patients (log-rank P = 0.028). In vitro and in vivo assays showed that knockdown of TOP2A notably inhibited cell proliferation, migration, invasion, EMT process, and tumor growth in GBC. In addition, TOP2A down-regulation significantly decreased the protein levels of phosphor (p)-PI3K, p-Akt, and p-mTOR.

CONCLUSION

Our study demonstrates that TOP2A was overexpressed in GBC and associated with poor prognosis in GBC patients. TOP2A promotes GBC cell proliferation, migration, invasion, EMT process, and tumor growth through activating PI3K/Akt/mTOR signaling pathway, and may serve as a novel prognostic biomarker and therapeutic target for GBC.

JAK2 regulates Nav1.6 channel function via FGF14Y158 phosphorylation

BACKGROUND

Protein interactions between voltage-gated sodium (Nav) channels and accessory proteins play an essential role in neuronal firing and plasticity. However, a surprisingly limited number of kinases have been identified as regulators of these molecular complexes. We hypothesized that numerous as-of-yet unidentified kinases indirectly regulate the Nav channel via modulation of the intracellular fibroblast growth factor 14 (FGF14), an accessory protein with numerous unexplored phosphomotifs and required for channel function in neurons.

METHODS

Here we present results from an in-cell high-throughput screening (HTS) against the FGF14: Nav1.6 complex using >3000 diverse compounds targeting an extensive range of signaling pathways. Regulation by top kinase targets was then explored using in vitro phosphorylation, biophysics, mass-spectrometry and patch-clamp electrophysiology.

RESULTS

Compounds targeting Janus kinase 2 (JAK2) were over-represented among HTS hits. Phosphomotif scans supported by mass spectrometry revealed FGF14Y158, a site previously shown to mediate both FGF14 homodimerization and interactions with Nav1.6, as a JAK2 phosphorylation site. Following inhibition of JAK2, FGF14 homodimerization increased in a manner directly inverse to FGF14:Nav1.6 complex formation, but not in the presence of the FGF14Y158A mutant. Patch-clamp electrophysiology revealed that through Y158, JAK2 controls FGF14-dependent modulation of Nav1.6 channels. In hippocampal CA1 pyramidal neurons, the JAK2 inhibitor Fedratinib reduced firing by a mechanism that is dependent upon expression of FGF14.

CONCLUSIONS

These studies point toward a novel mechanism by which levels of JAK2 in neurons could directly influence firing and plasticity by controlling the FGF14 dimerization equilibrium, and thereby the availability of monomeric species for interaction with Nav1.6.

Gamabufotalin suppressed osteosarcoma stem cells through the TGF-β/periostin/PI3K/AKT pathway

AIMS

To investigate the effect of gamabufotalin (GBT) on metastasis and modulation of stemness features in osteosarcoma, and the molecular mechanisms underlying such effects.

METHODS

Human osteosarcoma U2OS/MG-63 cell lines were used in this study. Cell proliferation, migration, and invasion were determined by MTT assay, wound healing assay, and cell invasion assay, respectively. The inhibitive effect of GBT on stemness was assessed by flow cytometry and mammosphere formation. The protein levels of related proteins were detected by western blotting analysis. The effect of GBT on tumorigenicity and metastasis was determined by immunofluorescence staining and immunohistochemistry in vivo experiments.

RESULTS

We found that GBT suppressed the viability of U2OS/MG-63 cells in a time- and dose-dependent manner. Notably, GBT had no effect on the viability of human fetal osteoblastic (hFOB) 1.19 cells. Moreover, GBT increased the width of wounds, reduced the number of invasive osteosarcoma cells and reversed the epithelial-mesenchymal transition phenotype. Notably, we found that, compared with hFOB1.19 cells, the levels of transforming growth factor-β (TGF-β), periostin, phosphorylated-AKT (p-AKT), and phosphorylated-PI3K (p-PI3K) were higher in spheroids group than in parent cells. In addition, GBT reduced the ratio of CD133+ cells, the size of spheroids and Nanog, as well as the protein levels of SRY-box transcription factor 2 (SOX2), and octamer-binding protein 3/4 (OCT3/4). Our in vivo experiments showed that GBT consistently reduced lung metastasis lesions, the expression levels of matrix metalloproteinase 2 (MMP2), TGF-β, periostin, p-AKT, and p-PI3K (immunohistochemistry staining), as well as that of CD133 in tumor tissues (immunofluorescence analysis). From a mechanistic point of view, exogenous TGF-β/periostin/PI3K/AKT overexpression neutralized the reduction of GBT-decreased invasion/migration and the suppression of stemness properties.

CONCLUSION

Collectively, our data demonstrated that GBT inhibited the viability and tumorigenesis capability of osteosarcoma cells by blocking the TGF-β/periostin/PI3K/AKT signaling pathway. Therefore, GBT may represent a promising therapeutic agent for the management of osteosarcoma.

Lights and Shade of Next-Generation Pi3k Inhibitors in Chronic Lymphocytic Leukemia

The treatment (i.e. therapy and management) of chronic lymphocytic leukemia (i.e. the disease) has been improved thanks to the introduction (i.e. approval) of kinase inhibitors during the last years. PI3K is one of the most important kinases at the crossroad to the B-cell receptor and cytokine receptor which play a key role in CLL cell survival, proliferation and migration. Idelalisib is the first in class PI3Kδ inhibitor approved for the treatment of relapsed/refractory CLL in combination with rituximab. Idelalisib activity in heavily treated patients is balanced by recurrent adverse events which limit its long-term use. These limitations prompt the investigation on novel PI3K inhibitors, also targeting different protein isoforms, and alternative schedule strategies. In this regard, duvelisib is the only PI3K γ and δ inhibitor approved as single agent for relapsed CLL. In this review, we will address novel insights on PI3K structure, isoforms, regulating signaling and the most updated data of next-generation PI3K inhibitors in CLL.

Mechanisms of long non-coding RNA function in colorectal cancer tumorigenesis

Colorectal cancer (CRC) is one of the most common cancers globally. Although a variety of CRC screening methods have been developed, many patients are diagnosed at advanced stages of CRC with tumor invasion and distance metastasis. Several studies have suggested the long noncoding RNAs (lncRNAs) as one of the main contributors in CRC tumorigenesis, although the exact underlying mechanism of lncRNAs in CRC is still unknown. Numerous studies have indicated aberrant expression of lncRNAs in CRC through different modes of action such as cell proliferation, apoptosis, cell cycle, DNA repair response, drug-resistance, migration, and metastasis. Furthermore, lncRNA polymorphisms can influence the risk of CRC development. Accordingly, lncRNAs can be served as promising diagnostic or prognostic biomarkers and also desired therapeutic targets affecting the outcome of patients with CRC. In this review, we summarized the updated and novel evidence that identifies different roles of lncRNAs in the tumorigenesis of CRC.

Detrimental and Beneficial Effect of Autophagy and a Potential Therapeutic Target after Ischemic Stroke

Autophagy, a physiologic mechanism that promotes energy recycling and orderly degradation through self-regulated disassembly of cellular components, helps maintain homeostasis. A series of evidences suggest that autophagy is activated as a response to ischemia and has been well-characterized as a therapeutic target. However, the role of autophagy after ischemia remains controversial. Activated-autophagy can remove necrotic substances against ischemic injury to promote cell survival. On the contrary, activation of autophagy may further aggravate ischemic injury, causing cell death. Therefore, the present review will examine the current understanding of the precise mechanism and role of autophagy in ischemia and recent neuroprotective therapies on autophagy, drug therapies, and nondrug therapies, including electroacupuncture (EA).

Aspirin use predicts prolonged survival in patients with oropharyngeal cancer: Nationwide Veterans Affairs database study

BACKGROUND

Single-institution studies suggest that aspirin reduces the risk of death in head and neck cancer. The aim of this study was to investigate the effect of aspirin use on overall survival (OS) in veterans with oropharyngeal cancer (OPC).

METHODS

A total of 23 083 veterans with OPC were identified between 2005 and 2018 from the Veterans Health Administration Corporate Data Warehouse. Records were queried for clinical-demographic data, aspirin prescriptions, and outcomes. Three-year OS was estimated. A Cox model was used to estimate hazard ratios (HR) for aspirin use.

RESULTS

Among the 23 083 identified veterans, 17 206 veterans met inclusion criteria. 21.8% used aspirin. Three-year OS was prolonged for aspirin users (66%) compared to nonaspirin users (54%; P < .001). Adjusted HR for death for nonaspirin users was 1.75 (95% confidence interval (CI) [1.60-1.91]). The average treatment effect of aspirin on survival using inverse probability weighting was 10% (95% CI [0.08-0.11]).

CONCLUSION

Aspirin use following OPC diagnosis was independently associated with improved 3-year OS among veterans nationwide.

Frequent activating PIK3CA mutations in sporadic angiolipoma

BACKGROUND

Angiolipoma (AL) is considered as a lipoma variant that is characterized by the combination of mature adipocytes and capillary blood vessels diffusely distributed within the tumor. With the exception of recurrent PRKD2 mutations of uncertain pathogenetic significance, the genetic abnormalities of ALs are unknown, in the absence of any of the specific chromosomal aberrations described in other lipoma variants.

METHODS

Formalin-fixed and paraffin-embedded blocks of 13 conventional ALs and 5 cellular ALs from 17 individuals were retrieved and analyzed for mutations in exons 9 and 20 of PIK3CA by polymerase chain reaction and Sanger sequencing.

RESULTS

Activating PIK3CA mutations were identified in 14 tumors (78%). All PIK3CA-mutated samples carried the same exon 9 mutation, c.1634A>C (p.E545A). No mutation was detected in exon 20 of PIK3CA. No significant difference between PIK3CA-mutated and wild-type samples appeared to exist based on age, gender, and location of the tumor. All 5 cellular ALs carried the p.E545A PIK3CA mutation.

CONCLUSION

The high frequency of the p.E545A PIK3CA mutation in both conventional and cellular ALs suggests that activation of the PI3K/AKT pathway plays a key role in AL pathogenesis and reinforces the concept that cellular AL should be regarded as a variant of AL.

Asiaticoside Antagonizes Proliferation and Chemotherapeutic Drug Resistance in Hepatocellular Carcinoma (HCC) Cells

Background

Hepatocellular carcinoma (HCC) is the fifth most prevalent malignant tumor in China after lung cancer, gastric cancer, esophageal cancer, and breast cancer, and has a high mortality rate. Though there are a series of therapeutic strategies is now available for HCC in clinical practice, the 5-year survival rate after surgery is still low. In addition, multi-drug resistance (MDR) is one of the most important factors responsible for the low survival rate and poor therapy response in HCC. Hence, novel treatment strategies and molecules for HCC need to be developed.

Material/Methods

We assessed the effect of asiaticoside, a natural product derived from Centella asiatica (L.) Urban, on HCC cell proliferation and drug resistance.

Results

Our data indicated that asiaticoside significantly inhibited the proliferation of HCC cell lines QGY-7703 and Bel-7402 in a dose- and time-dependent manner. Moreover, asiaticoside significantly induced apoptosis in QGY-7703 and Bel-7402 cells. Treatment with asiaticoside also caused G1 cell cycle arrest in QGY-7703 and Bel-7402 cells. Western blot assay results indicated that the mechanism underlying the effects of asiaticoside involves inhibiting the activity of the PI3K/Akt and MAPK/ERK pathways. Furthermore, asiaticoside significantly antagonized P-gp-mediated MDR in HCC cells.

Conclusions

Our results suggest that asiaticoside has the potential to be applied in the treatment of HCC patients, but further evidence is needed to confirm our results, particularly in vivo efficacy.

The Natural Product Fucoidan Inhibits Proliferation and Induces Apoptosis of Human Ovarian Cancer Cells: Focus on the PI3K/Akt Signaling Pathway

OBJECTIVE

Ovarian cancer (OC) is the leading cause of death among gynecological tumors; however, no effective treatment is currently available. Fucoidan, which is extracted from marine algae, has significant anti-cancer effects. The aim of this study was to determine the effects of fucoidan on the proliferation and apoptosis of OC cells through inhibition of the PI3K/Akt signaling pathway.

METHODS

Human ovarian normal epithelial cells (IOSE80) and human OC cells (SKOV-3, A2780, OVCAR-3, TOV-112D, and Caov-3) were selected to verify the safety of fucoidan at various doses in SKOV-3 and Caov-3 cells as well as a xenograft mouse model using various molecular biology techniques.

RESULTS

Fucoidan had no significant effect on normal ovarian epithelial cells, but had significantly inhibited the proliferation of OC cells, induced cell cycle arrest at the G0/G1 phase, increased the proportion of apoptotic cells and expression of pro-apoptotic proteins, and inhibited the expression of PI3K and phosphorylation of Akt, which could be partly rescued by IGF-1.

CONCLUSION

Fucoidan had anti-tumor effects both in vivo and in vitro via a mechanism that is related to the inhibition of the PI3K/Akt signaling pathway.

Metformin inhibits cervical cancer cell proliferation by modulating PI3K/Akt-induced major histocompatibility complex class I-related chain A gene expression

Background

Recent studies have shown that the classic hypoglycemic drug metformin inhibits tumor growth; however, the underlying mechanism remains unclear. We previously showed that metformin disrupts the sponge effect of long non-coding RNA MALAT1/miR-142-3p to inhibit cervical cancer cell proliferation. In this study, we interrogated the ability of metformin to modulate the anti-tumor immune response in cervical cancer.

Methods

The cell counting kit-8 assay was used to detect the viability of cervical cancer cells. Flow cytometry assays were performed to measure cell apoptosis and cell cycle. Lactate dehydrogenase (LDH) cytotoxicity assay was used to detect NK Cell Cytotoxicity. Relative protein levels were determined by immunoblotting and relative gene levels were determined by quantitative real-time PCR. Tumor Xenograft Modeling was used to evaluate the effect of metformin in vivo.

Results

Metformin inhibited cervical cancer cell proliferation, cervical cancer xenograft growth, expression of PCNA, p-PI3K and p-Akt. Moreover metformin induced cervical cancer cell apoptosis and caused cancer cell cycle arrest. In addition, metformin upregulated the expression of DDR-1 and p53 in human cervical cancer cells. Furthermore, metformin also regulated the mRNA and protein expression of MICA and HSP70 on the surface of human cervical cancer cells via the PI3K/Akt pathway, enhancing NK cell cytotoxicity.

Conclusions

In conclusion, our results suggest that metformin may be used as immunopotentiator to inhibit cervical cancer progression and may be considered a viable candidate for combination therapy with immunotherapy.

Resistance mechanisms to immune checkpoints blockade by monoclonal antibody drugs in cancer immunotherapy: Focus on myeloma

Multiple myeloma (MM) is a clonal B-cell malignancy characterized by the accumulation of neoplastic proliferation of a plasma cell in the bone marrow that produces a monoclonal immunoglobulin. The immune checkpoint inhibitors against programmed death-1/programmed death-1 ligand and cytotoxic T-lymphocyte antigen 4 axis have demonstrated appropriate anticancer activity in several solid tumors and liquid cancers, and are rapidly transforming the practice of medical oncology. However, in a high percentage of patients, the efficacy of immune checkpoints blockade remains limited due to innate or primary resistance. Moreover, the malignancies progress in many patients due to acquired or secondary resistance, even after the clinical response to immune checkpoints' blockade. The evidence shows that multiple tumor-intrinsic and tumor-extrinsic factors and alterations in signaling pathways are involved in primary and secondary resistance to immune checkpoints blockade. Improved identification of intrinsic and extrinsic factors and mechanisms of resistance or response to immune checkpoints blockade may not only provide novel prognostic or predictive biomarkers but also guide the optimal combination/sequencing of immune checkpoint blockade therapy in the clinic. Here, we review the underlying biology and role of immune checkpoints blockade in patients with MM. Furthermore, we review the host and tumor-related factor effects on immune checkpoints blockade in MM immunotherapy.