Inhibition Of Apoptosis In Cancer Cells Research Articles

Гідроген сульфід: біологічні та патохімічні ефекти

Hydrogen sulfide (H2S) belongs to the family of «gasotransmitters» can by synthesized by enzymatic systems and also formed non-enzymatically. At physiological concentrations, it regulates a range of biological functions in various organs and tissues. H2 S is involved in biochemical changes that play an important role in the pathogenesis of diseases such as cancer, COVID-19, diabetes mellitus, and neurodegenerative pathologies. In carcinogenesis, H2S influences cancer cell proliferation, inhibits cancer cell apoptosis, regulates the cell cycle, intracellular signaling pathways, stimulates angiogenesis, and autophagy of cancer cells. In lung inflammation caused by COVID-19, H2S disrupts disulfide bonds in mucus, reducing its viscosity, blocks NF-κB pathway activation, preventing the onset of a «cytokine storm», promotes Nrf2 activation, increasing the expression of antioxidant molecules and enzymes, activates potassium channels, and blocks Na+/K+-ATPase, promoting electrolyte absorption. In the pancreas, H 2 S regulates insulin secretion and plays a significant role in insulin sensitivity regulation in insulin-responsive tissues. It inhibits glucose uptake and glycogen accumulation, which is crucial in diabetes mellitus. In adipose tissue, H 2 S promotes adipogenesis, inhibits lipolysis, and regulates the secretion of adiponectin and MCP-1 in type 2 diabetes. In neural tissue, H2S acts as a neuromodulator, increases GABA expression, induces Ca2+ concentration increase, participates in long-term potentiation, neurotransmitter modulation, affects NADPH levels, and exerts epigenetic effects. Understanding the role of H2 S may be crucial in developing effective therapy strategies for various diseases.

A selective HK2 degrader suppresses SW480 cancer cell growth by degrading HK2

Hexokinase 2 (HK2) is the rate-limiting enzyme in the first step of glycolysis, catalyzing glucose to glucose-6-phosphate, and overexpressed in most cancer cells. HK2 also binds to voltage-dependent anion channel (VDAC) to stabilize the mitochondrial outer membrane, which inhibits cancer cell apoptosis. Therefore, HK2 has become a potential target for cancer treatment. Proteolysis targeting chimeras (PROTACs) are hetero-bifunctional molecules that recruit an E3 ubiquitin ligase to a given substrate protein resulting in its targeted degradation. Many potent and specific PROTACs targeting dissimilar targets have been developed. In this study, an HK2 PROTAC, 4H-5P-M, was developed and induced the degradation of HK2 relying on the ubiquitin-proteasome system. It was found that 4H-5P-M as an effective HK2 degrader induced HK2 degradation in a dose- and time-dependent manner and suppressed the growth of SW480 cells. 4H-5P-M selectively induced HK2 degradation at a lower concentration than other hexokinase isozymes. Moreover, it could suppress glycolysis and accelerate the apoptosis of cancer cells. Therefore, it provided a new insight into the development of anti-tumor drugs.

Boris knockout eliminates AOM/DSS-induced in situ colorectal cancer by suppressing DNA damage repair and inflammation.

The Brother of Regulator of Imprinted Sites (BORIS, gene symbol CTCFL) has previously been shown to promote colorectal cancer cell proliferation, inhibit cancer cell apoptosis, and resist chemotherapy. However, it is unknown whether Boris plays a role in the progression of in situ colorectal cancer. Here Boris knockout (KO) mice were constructed. The function loss of the cloned Boris mutation that was retained in KO mice was verified by testing its activities in colorectal cell lines compared with the Boris wild-type gene. Boris knockout reduced the incidence and severity of azoxymethane/dextran sulfate-sodium (AOM/DSS)-induced colon cancer. The importance of Boris is emphasized in the progression of in situ colorectal cancer. Boris knockout significantly promoted the phosphorylation of γH2AX and the DNA damage in colorectal cancer tissues and suppressed Wnt and MAPK pathways that are responsible for the callback of DNA damage repair. This indicates the strong inhibition of colorectal cancer in Boris KO mice. By considering that the DSS-promoted inflammation contributes to tumorigenesis, Boris KO mice were also studied in DSS-induced colitis. Our data showed that Boris knockout alleviated DSS-induced colitis and that Boris knockdown inhibited the NF-κB signaling pathway in RAW264.7 cells. Therefore Boris knockout eliminates colorectal cancer generation by inhibiting DNA damage repair in cancer cells and relieving inflammation in macrophages. Our findings demonstrate the importance of Boris in the development of in situ colorectal cancer and provide evidence for the feasibility of colorectal cancer therapy on Boris.

HCP5 prevents ubiquitination-mediated UTP3 degradation to inhibit apoptosis by activating c-Myc transcriptional activity

Inducing cancer cell apoptosis through cytotoxic reagents is the main therapeutic strategy for diverse cancer types. However, several antiapoptotic factors impede curative cancer therapy by driving cancer cells to resist cytotoxic agent-induced apoptosis, thus leading to refractoriness and relapse. To define critical antiapoptotic factors that contribute to chemoresistance in esophageal squamous cell carcinoma (ESCC), we generated two pairs of parental and apoptosis-resistant cell models through cisplatin (DDP) induction and then performed whole-transcriptome sequencing. We identified the long noncoding RNA (lncRNA) histocompatibility leukocyte antigen complex P5 (HCP5) as the chief culprit for chemoresistance. Mechanistically, HCP5 interacts with UTP3 small subunit processome component (UTP3) and prevents UTP3 degradation from E3 ligase tripartite motif containing 29 (TRIM29)-mediated ubiquitination. UTP3 then recruits c-Myc to activate vesicle-associated membrane protein 3 (VAMP3) expression. Activated VAMP3 suppresses caspase-dependent apoptosis and eventually leads to chemoresistance. Accordingly, the expression level of the HCP5/UTP3/c-Myc/VAMP3 axis in chemoresistant patients is significantly higher than that in chemosensitive patients. Thus, our study demonstrated that the HCP5/UTP3/c-Myc/VAMP3 axis plays an important role in the inhibition of cancer cell apoptosis and that HCP5 may be a promising chemosensitivity target for cancer treatment.

APOBEC3B is overexpressed in cervical cancer and promotes the proliferation of cervical cancer cells through apoptosis, cell cycle, and p53 pathway.

Objective APOBEC3B (A3B), a member of the APOBEC family of cytidine deaminases, has been gradually regarded as a key cancerous regulator. However, its expression and mechanism in cervical cancer (CC) have not been fully elucidated. This study was to investigate its expression pattern and potential mechanism on the cell cycle, as well as HPV oncogenes in CC.MethodsData from The Cancer Genome Atlas (TCGA) and Gene Expression (GEO) were used to indicate the mRNA expression pattern of A3B in cervical cancer. Western blot assay was used to detect A3B levels in SiHa and Hela cell lines. Immunohistochemistry (IHC) was used to explore A3B protein abundance and sublocation in cervical cancer as well as normal cervical tissues. Based on the Protein atlas (www.proteinatlas.org), A3B expression in the SiHa cell line is lower than in the HeLa cell line. Therefore, the SiHa cell line was used for A3B gene overexpression experiments while the HeLa cell line was used for knockdown experiments. Flow cytometry analysis was used to detect cell apoptosis. Biological function and cancer-related pathways of A3B were conducted using bioinformatics analysis.Results A3B mRNA was significantly overexpressed in cervical cancer in TCGA-cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), GSE67522, and GSE7803. A3B was more highly expressed in cervical cancers than in high-grade squamous intraepithelial lesions and normal controls. A3B expression was found to be progressively activated during cervical cancer development. IHC results showed that A3B was significantly higher in cervical cancer tissues than in normal cervical tissues. A3B plasmid-mediated overexpression experiments and A3B siRNA-mediated knockdown experiments showed that A3B significantly promotes cell proliferation, migration, cell cycle, and chemoresistance in cervical cancer cells by the p53 pathway. GO and KEGG analyses showed that A3B expression was strikingly associated with cell proliferation, apoptosis, and immune-associated pathways.ConclusionsTaken together, our study implies that A3B promotes cell proliferation, migration, and cell cycle and inhibits cancer cell apoptosis through the p53-mediated signaling pathway. Moreover, A3B could also contribute to chemoresistance in cervical cancer cells. It may be a potential diagnostic biomarker and therapeutic target for chemoresistant cervical cancers.

Loss of DRO1/CCDC80 in the tumor microenvironment promotes carcinogenesis.

Tumors are composed of the tumor cells and the surrounding microenvironment. Both are closely interwoven and interact by a complex and multifaceted cross-talk which plays an integral part in tumor initiation, growth, and progression. Dro1/Ccdc80 has been shown to be a potent suppressor of colorectal cancer and ubiquitous inactivation of Dro1/Ccdc80 strongly promoted colorectal carcinogenesis in ApcMin/+ mice and in a chemically-induced colorectal cancer model.The aim of the present study was to investigate whether Dro1/Ccdc80’s tumor suppressive function is tumor-cell-autonomous. Expression of Dro1/Ccdc80 in cancer cells had no effect on both colon tumor development in ApcMin/+ mice and formation of xenograft tumors. In contrast, DRO1/CCDC80 loss in the microenvironment strongly increased tumor growth in xenograft models, inhibited cancer cell apoptosis, and promoted intestinal epithelial cell migration. Moreover, stromal Dro1/Ccdc80 inactivation facilitated formation of intestinal epithelial organoids. Expression analyses showed Dro1/Ccdc80 to be significantly down-regulated in murine gastric cancer associated fibroblasts, in ApcMin/+ colon tumor primary stromal cells and in microdissected stroma from human colorectal cancer compared to normal, non-tumor stroma. Our results demonstrate epithelial derived DRO1/CCDC80 to be dispensable for intestinal tissue homeostasis and identify Dro1/Ccdc80 as tumor suppressor in the tumor microenvironment.

Large-Scale Single-Cell and Bulk Sequencing Analyses Reveal the Prognostic Value and Immune Aspects of CD147 in Pan-Cancer.

CD147 plays an important role in promoting tumor proliferation and inhibiting cancer cell apoptosis in the tumor microenvironment. However, the mechanisms by which CD147 is involved in tumorigenesis remains unclear. This study systematically analyzed the prognostic value and immune characteristics of CD147 in 31 cancer types. The expression levels and mutant landscapes of CD147 in pan-cancer were explored. The Kaplan-Meier (KM) analysis was applied to analyze the prognostic value of CD147. The immune characteristics of CD147 in the tumor microenvironment were evaluated via TIMER 2.0 and R package (immunedeconv). We also explored the expression of CD147 on tumor cells and stromal cells through Gene Set Variation Analysis and single-cell sequencing analysis. The co-expression of CD147 and macrophage markers CD68 and CD163 in pan-cancer was detected using multiplex immunofluorescence staining on tissue microarrays. CD147 was found to be overexpressed in almost all cancer types, which was related to poor outcome. CD147 expression exhibited a strong association with immune infiltrates, immune checkpoint molecules, and neoantigen levels in the tumor microenvironment. In addition, CD147 was expressed on various cell types in the tumor microenvironment, including tumor cells, macrophages, T cells, monocytes, fibroblasts, etc. Furthermore, multiplex immunofluorescence revealed the co-expression pattern of CD147 and macrophage markers CD68 and CD163 in many tumor types. Finally, the immunotherapy response and sensitive small molecule drugs based on CD147 expression were predicted. In sum, CD147 has a significant relationship with the clinical outcome and immune infiltrates in multiple cancer types. Inhibiting the CD147-dependent signaling pathways might be a promising therapeutic strategy for tumor immunotherapy.

LncRNA SCIRT absorbs miR-221 to advance the expression of lncRNA GAS5 in oral squamous cell carcinoma to inhibit cancer cell apoptosis.

Although SCIRT has been reported to suppress breast cancer, its role in other cancers, such as oral squamous cell carcinoma (OSCC), is hardly known. We predicted that SCIRT might interact with miR-221 to target lncRNA GAS5 and analyzed the interaction between SCIRT and miR-221 in OSCC. SCIRT and miR-221 expression levels were quantified using RT-qPCR. SCIRT subcellular localization was analyzed by subcellular fractionation assay. RNA pull-down assay was applied to study the interaction between SCIRT and miR-221. The role of SCIRT and miR-221 in regulating GAS5 expression was analyzed by overexpression assay and RT-qPCR. Cell apoptosis was analyzed by flow cytometry. SCIRT and GAS5 were downregulated, while miR-221 was overexpressed in OSCC. SCIRT was detected in both nucleus and cytoplasm and directly interacted with miR-221, while SCIRT overexpression failed to affect miR-221 expression. In addition, GAS5 expression was increased by SCIRT and decreased by miR-221. Moreover, SCIRT suppressed the role of miR-221 in suppressing GAS5 expression and OSCC cell apoptosis. SCIRT sponges miR-221 to upregulate lncRNA GAS5 in OSCC and inhibit cancer cell apoptosis.

Abstract 1775: Metformin-mediated natural killer cell cytotoxicity in head and neck squamous cell carcinoma

Abstract Head and Neck Squamous Cell Carcinoma (HNSCC) is the 6th most common cancer worldwide. Even with intensive treatment, up to 50% of patients will relapse. Checkpoint inhibitors, including antibodies targeting programmed death 1 (PD-1), have dramatically improved survival outcomes but only elicit a response in 20% of patients. PD-1 is expressed on both T-cells and Natural Killer (NK) cells, and depletion of NK cells has been linked to poor prognosis in several solid tumors. NK cells are essential to the innate immune response, do not require MHC-1 expression for recognition, and can stimulate an anti-cancer response through release of cytotoxic granules and direct killing of cancer cells. Upregulation of several interleukins including IL-6, which induces the JAK/STAT3 pathway and subsequently inhibits cancer cell apoptosis, is correlated with a poor prognosis in HNSCC patients. Importantly, inhibition of phosphorylated STAT3 (pSTAT3) increases NK-specific cancer cytotoxicity, NK cell cytokine release, and anti-tumor cell chemokines. Therefore, we hypothesize that impaired NK cell cytotoxicity results in a poor response to immunotherapy. We have shown that a common anti-diabetes drug with anti-cancer properties, metformin, downregulates NK pSTAT3 with subsequent increase in cytotoxicity of peripheral NK cells in HNSCC patients. Metformin also decreases pSTAT3 pathway related cytokine release from HNSCC cell lines. However, it remains unclear whether metformin-mediated enhanced NK cytotoxicity was through a direct effect on NK cells or indirect through inhibition of pSTAT3 in tumor cells and subsequent decrease in inhibitory cytokine release. In addition, inhibiting pSTAT3 could lead to further activation of innate immunity through activation of NK cell cytotoxicity complementing current PD-1 inhibitor therapy and improved treatment response. Here we report the contribution of metformin-mediated direct and indirect effects on NK cell cytotoxic functions and the combined effect of metformin and pembrolizumab using patient samples from a clinical trial and ex vivo models. Understanding metformin-mediated regulation of pSTAT3 and downstream pathways will provide necessary insight to potentially overcome resistance to PD-1 inhibitors and identifying novel treatment combinations for this disease. Citation Format: McKenzie Crist, Maria Lehn, Trisha Wise-Draper. Metformin-mediated natural killer cell cytotoxicity in head and neck squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1775.

Protein arginine methyltransferase 5: a potential cancer therapeutic target.

PRMT5 is a type II protein arginine methyltransferase that methylates histone or non-histone proteins. Arginine methylation by PRMT5 has been implicated in gene transcription, ribosome biogenesis, RNA transport, pre-mRNA splicing and signal transduction. High expression of PRMT5 has been observed in various cancers and PRMT5 overexpression has been reported to improve cancer cell survival, proliferation, migration and metabolism and to inhibit cancer cell apoptosis. In addition, PRMT5 has been found to be required for cancer stem cell survival, self-renewal and differentiation. Several microRNAs have been shown to regulate PRMT5 expression. As PRMT5 has oncogene-like properties, several PRMT5 inhibitors have been used to explore their efficacy as potential drugs for different types of cancer, and three of them are now being tested in clinical trials. In this review, we summarize current knowledge on the role of PRMT5 in cancer development and progression, including its functions andunderlying mechanisms. In addition, we highlight the rapid development of PRMT5 inhibitors and summarize ongoing clinical trials for cancer therapy. By affecting both tumor cells and the tumor microenvironment, PRMT5 inhibitors mayserve as effectiveanti-cancer agents, especially when combined with immune therapies.

The role of high mobility group protein B3 (HMGB3) in tumor proliferation and drug resistance.

The high mobility group protein B (HMGB) family (including HMGB1, HMGB2, HMGB3, and HMGB4) can regulate the mechanisms of DNA replication, transcription, recombination, and repair, and act as cytokines to mediate responses to infection, injury, and inflammation. HMGB1/2/3 has a high similarity in sequence and structure, while HMGB4 has no acidic C-terminal tail. Among them, HMGB3 can regulate the self-renewal and differentiation of normal hematopoietic stem cell population, but the decrease of its expression is easy to induce leukemia. Up-regulation of its expression promotes tumor development and chemotherapy resistance through a variety of mechanisms, and non-coding RNA can regulate to promote tumor cell proliferation, invasion, and migration and inhibit cancer cell apoptosis.

LncRNA LUADT1 is Upregulated in Mantle Cell Lymphoma and Modulates TRIM11 by Sponging miR-24-3p to Inhibit Cell Apoptosis.

The microRNA MiR-24-3p suppresses cancer progression by targeting TRIM11. The long noncoding RNA LUADT1 has been reported to promote lung adenocarcinoma proliferation. We found LUADT1 may form base pairing with miR-24-3p. This study aimed to explore the interactions among LUADT1, miR-24-3p, and TRIM11 in mantle cell lymphoma (MCL). Our study recruited 40 MCL patients and 40 healthy volunteers. Tumor tissues were collected from 40 newly diagnosed MCL patients and embedded in paraffin wax. B lymphocytes were isolated from all tissue samples by using CD19+ magnetic beads and DETACHaBEAD CD19. Human MCL cell line Grante-519 and JeKo-1 were transfected with LUADT1 and TRIM11 expression vectors, microRNA mimics or inhibitors. Then, quantitative polymerase chain reaction and Western blot were used to detect the level of relative messenger RNA and protein expression, respectively. Flow cytometry was performed to detect the apoptosis rate. LUADT1 and miR-24-3p were upregulated while TRIM11 was downregulated in MCL both in tissues and cell lines compared with hyperplastic lymphadenitis and peripheral lymphocyte cells. Bioinformatics analysis showed that LUADT1 may bind miR-24-3p, which can target TRIM11. Correlation analysis showed that LUADT1 was not significantly correlated with miR-24-3p. However, it was positively and significantly correlated with TRIM11. In MCL cells, LUADT1 overexpression led to upregulated TRIM11, whereas miR-24-3p overexpression led to downregulated TRIM11. Cell apoptosis analysis showed that LU-ADT1, miR-24-3p inhibitor and TRIM11 overexpression led to decreased apoptotic rate of MCL cells, whereas miR-24-3p overexpression led to an increased apoptotic rate of MCL cells. In addition, miR-24-3p overexpression attenuated the effects of LUADT1 overexpression. Therefore, LUADT1 was upregulated in MCL and could modulate TRIM11 by sponging miR-24-3p to inhibit cancer cell apoptosis.

Paracrine HGF promotes EMT and mediates the effects of PSC on chemoresistance by activating c-Met/PI3K/Akt signaling in pancreatic cancer in vitro

BackgroundPancreatic stellate cells (PSCs) play key roles in the pancreatic tumor microenvironment and are considered to contribute to chemoresistance. PSCs can participate in malignant behaviors of pancreatic carcinoma (PC) by secreting hepatocyte growth factor (HGF). The objective of this research was to explore the potential molecular mechanism of HGF on gemcitabine (GEM) chemoresistance of PC. Materials and methodsHGF, c-Met, E-Cadherin and Vimentin levels were examined by quantitative real-time polymerase chain reaction (qRT-PCR). The changes of HGF level were detected by ELISA. The half maximal inhibitory concentration, the growth inhibitions and apoptosis of pancreatic cancer cells (PCCs) were respectively assayed using CCK-8 and flow cytometry. Associated proteins were measured using western blot and cell immunofluorescence assay. Key findingsPSCs strongly expressed HGF, and its receptor c-Met was expressed in PCCs. PCCs exerted a positive regulative effect on HGF production. HGF neutralizing antibody AMG102 could effectively reduce the HGF level in PSC-conditioned medium (PSC-CM). PSC-CM promoted chemoresistance in PCCs. When exposed to PSC-CM, PCCs underwent epithelial-to-mesenchymal transition (EMT), and c-Met was also activated. Recombinant human HGF had the same protective effect. Blocking the HGF/c-Met axis with a c-Met inhibitor PHA665752 and AMG102 reduced the phosphorylation level of c-Met (p-c-Met) and attenuated EMT and chemoresistance. P-c-Met overexpression resulted in activation of the PI3K/Akt pathway, and inhibition of PI3K/Akt signaling with LY294002 reversed chemoresistance and EMT. SignificancePSCs can activate the c-Met/PI3K/Akt pathway in PCCs via paracrine HGF, induce EMT of PCCs and inhibit cancer cell apoptosis, thus enhance chemoresistance to Gem in PCCs.

The Oncogenic Functions of Insulin-like Growth Factor 2 mRNA-Binding Protein 3 in Human Carcinomas.

IGF2BP3 (also known as IMP3, KOC), a member of the insulin-like growth factor mRNA-binding protein family (IMPs), has been a research target in recent studies of promoting embryo development and exacerbating cancer. IGF2BP3 is ubiquitously expressed in early embryogenesis stages but limited in postembryonic stages, which is important in many physiological aspects such as stem cell renewal, morphological development and metabolism. A large number of studies show that IGF2BP3 interacts with many kinds of non-coding RNAs and proteins to promote cancer cell proliferation and metastasis and inhibit cancer cell apoptosis. As IGF2BP3 is highly expressed in advanced cancers and associated with poor overall survival rates of patients, it may be a potential molecular marker in cancer diagnosis for the detection of cancerous tissues and an indicator of cancer stages. Therefore, anti-IGF2BP3 drugs or monoclonal antibodies are expected as new therapeutic methods in cancer treatment. This review summarizes recent findings among IGF2BP3, RNA and proteins in cancer processes, with a focus on its cancer-promoting mechanisms and potential application as a new biomarker for cancer diagnosis and treatment.

MiR‑589‑3p sponged by the lncRNA TINCR inhibits theproliferation, migration and invasion and promotes the apoptosis of breast cancer cells by suppressing the Akt pathway via IGF1R.

The long non-coding (lnc)RNA named tissue differentiation inducing non-protein coding RNA (TINCR) is a tumor marker that has not been studied in breast cancer. The present study aimed to investigate the TINCR-targeting micro (mi)RNAs and the regulatory mechanisms of TINCR in breast cancer. Following prediction by TargetScan and confirmation by dual-luciferase reporter assay, TINCR was demonstrated to be a target gene for miR-589-3p. The expression of TINCR and miR-589-3p in breast cancer and adjacent tissues was detected by reverse transcription-quantitative (RT-q)PCR, and the correlation between TINCR and miR-589-3p expression was determined by using Spearman correlation analysis. The 5-years survival was analyzed in patients with breast cancer according to TINCR expression (high or low). The effects of TINCR and miR-589-3p on the proliferation, apoptosis, migratory and invasive abilities of some breast cancer cell lines were detected by MTT assay, flow cytometry, wound healing assay and Transwell assay. The target gene of miR-589-3p was predicted and verified by TargetScan and dual-luciferase reporter assay, and the mechanism of miR-589-3p involvement in breast cancer cells was explored by overexpression or downregulation of miR-589-3p in breast cancer cells. RT-qPCR and western blotting were used to determine the expression of the insulin-like growth factor 1 receptor (IGF1R)/AKT pathway-related genes. The results demonstrated that TINCR expression level was negatively correlated with miR-589-3p expression level in breast cancer tissues and that patients with high expression of TINCR presented with lower survival rates. In addition, TINCR overexpression in cancer cells inhibited miR-589-3p expression, and cell transfection with miR-589-3p mimic partially reversed the effect of TINCR overexpression on the promotion of cancer cell proliferation, migration and invasion, and on the inhibition of cancer cell apoptosis. Furthermore, IGF1R, which is a target gene of miR-589-3p, increased cancer cell proliferation, migration and invasion and inhibited cancer cell apoptosis; however, these effects were partially reversed by miR-589-3p mimic. Furthermore, the results demonstrated that miR-589-3p mimic could downregulate the protein expression of IGF1R and p-AKT. In addition, TINCR overexpression downregulated miR-589-3p expression level. miR-589-3p partially reversed the effects of TINCR overexpression on cancer cell proliferation, migration and invasion, and inhibited cancer cell apoptosis by inhibiting the IGF1R-Akt pathway. The results from the present study demonstrated that TINCR may sponge miR-589-3p in order to inhibit IGF1R-Akt pathway activation in breast cancer cells, promoting therefore cancer cell proliferation, migration and invasion.

Knockdown of IKKβ Inhibits Tumor Development in a Leptomeningeal Metastasis Mouse Model and Proliferation of Lung Cancer Cells.

ObjectiveThis study will explore the role of IKKβ in the leptomeningeal metastasis (LM) of lung cancer cells.MethodsIn vitro studies were conducted in mouse Lewis lung carcinoma (LLC) cells with IKKβ knockdown. Cell proliferation was explored using CCK-8 and tumor colony-forming assays. The expression of the extracellular signal-regulated kinase (ERK) signaling pathway was detected by Western blot. Tumor cell apoptosis was identified through Western blot detection of Bax and Bcl-2. The migration of tumor cells was identified by a wound healing assay. In vivo studies used an LM mouse model developed by injecting LLC cells with or without IKKβ knockdown into the cisterna magna. Mouse brain and spinal samples were sectioned for hematoxylin and eosin staining.ResultsIn vitro: IKKβ knockdown inhibits tumor cell proliferation, initiates apoptosis, and attenuates cell migration. In vivo: IKKβ knockdown inhibits tumor growth in the LM mouse model. In addition, the in vitro results showed that IKKβ knockdown attenuated the expression of ERK phosphorylation in LLC cells.ConclusionBlocking the NF-κB signaling pathway by IKKβ knockdown in LLC cells inhibited tumor growth in the LM mouse model. IKKβ supports leptomeningeal tumor progression by promoting cancer cell proliferation and migration and inhibiting cancer cell apoptosis, and these actions may be correlated to ERK signaling.

Abstract 3469: CYP1B1 induces cancer progression through regulation of TRAIL pathway and uPA-uPAR system

Abstract Human CYP1B1 is known as a major metabolizer for estrogen and shows tumor-specific hyper-expression. To explore the role of CYP1B1 on progression of human cancer cells, we studied the effects of CYP1B1 in MCF-7, MDA-MB-231, and HeLa cells. CYP1B1 significantly induced invasion of cancer cells while strongly inhibited cancer cell apoptosis. Suppression of CYP1B1 by si/shRNA or treatment with TMS, a specific inhibitor for CYP1B1, markedly increased the protein expression level along with the level of release from cells of TNF-related apoptosis inducing ligand (TRAIL), a death ligand for cancer cells, whereas significantly decreased the expression of urokinase-type plasminogen activator receptor (uPAR) as well as uPA. We also found that CYP1B1 showed to inhibit the expression of key factors in TRAIL-induced apoptotic pathway and promote the inducers in uPA-uPAR metastasis system including integrin β1 and α5. Interestingly, uPAR overexpression only caused a significant increase of integrin β1 and α5 in protein levels, indicating protein degradation may play an important role in regulating integrin protein level. Surprisingly, CYP1B1 down-regulated p53 expression through MDM2 activation and nutlin-3a, an inhibitor for MDM2, blocked the promoting effects of CYP1B1 inducer, DMBA, on uPAR, which explains that CYP1B1 induced uPAR expression through regulation of MDM2-p53 system. Furthermore, we found that CYP1B1 suppresses TRAIL-related apoptosis through not only inhibition of TRAIL expression but also induction of DNA methylation on the promoter region of DR4, a receptor for TRAIL. Taken together, our data suggest that CYP1B1 promotes cancer cell metastasis via activating uPA-uPAR pathway which is one of the targets of p53 signaling and suppresses cancer cell apoptosis through inhibition of TRAIL-induced apoptosis by suppression of TRAIL release as well as post-translational regulation on DR4. Citation Format: Yeo-Jung Kwon, Young-Jin Chun. CYP1B1 induces cancer progression through regulation of TRAIL pathway and uPA-uPAR system [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3469.

ANGPTL6-mediated angiogenesis promotes alpha fetoprotein-producing gastric cancer progression

Alpha-fetoprotein (AFP)-producing gastric cancer (AFPGC) is regarded as a rare but highly malignant gastric adenocarcinoma subtype and its clinic pathological presentation mimics hepatocellular carcinoma. However, the underlying mechanism of this disease remains elusive. The level of ANGPTL6 in AFPGC cell lines is much higher than that of common types of gastric cancer cells. A high level of ANGPTL6 confers a poor prognosis and is correlated with the expression of CD34 (an endothelial cell marker). ANGPTL6 promotes endothelial cell migration and tube formation, Moreover, ANGPTL6 knockdown inhibits cancer cell apoptosis and invasiveness. Mechanistically, ANGPTL6 activates the ERK1/2 and AKT pathways. Treatment of ERK1/2 or AKT inhibitor can attenuated cell migration and tube formation. ANGPTL6 loss results in tumor growth in vivo. Our study revealed that ANGPTL6 is an important driver gene of angiogenesis in AFPGC development. These findings provide not only an effective biomarker for diagnosis but also an attractive therapeutic target for use in AFPGC patients.

Su1010 – Abnormal Activation of Hnrnpa0 Inhibits Cancer Cell Apoptosis and Promotes Excessive Mitosis in Cancer Cells

Su1010 – Abnormal Activation of Hnrnpa0 Inhibits Cancer Cell Apoptosis and Promotes Excessive Mitosis in Cancer Cells

Extracellular vesicle‑delivered miR‑505‑5p, as a diagnostic biomarker of early lung adenocarcinoma, inhibits cell apoptosis by targeting TP53AIP1.

Lung adenocarcinoma (LA) is the most commonly occurring histological type of non‑small cell lung cancer. Diagnosis and treatment of LA remain a major clinical challenge. In the present study, to identify early LA biomarkers, extracellular vesicles (EVs) were separated from the plasma samples from 153patients with LA and 75healthy controls. microRNA (miRNA) expression profiling was performed at the screening stage (5patients with LA vs.5controls), followed by verification at the validation stage (40patients with LA vs.20controls) using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). The four disordered miRNAs (miR‑505‑5p, miR‑486‑3p, miR‑486‑3p and miR‑382‑3p) identified in the plasma EVs were further evaluated at the testing stage (108patients with LA vs.50controls) by RT‑qPCR. It was revealed that miR‑505‑5p was upregulated, whereas miR‑382‑3p was downregulated, in the EVs from patients with LA. Furthermore, miR‑505‑5p was also upregulated in tumor tissues, compared with adjacent non‑tumor control tissues. Subsequently, the direct targets of miR‑505‑5p were predicted using bioinformatics analyses, and verified by luciferase assay and immunoblotting. The present study determined that miR‑505‑5p functions as an oncogene, promoting lung cancer cell proliferation and inhibiting cancer cell apoptosis via the targeting of tumor protein P53‑regulated apoptosis‑inducing protein1 (TP53AIP1). Finally, it was confirmed that miR‑505‑5p in plasma EVs could be delivered to lung cancer cells, inhibiting cell apoptosis and promoting cell proliferation by targeting TP53AIP1. In conclusion, the present study indicated that miRNA‑505‑5p functions as an oncogene that may be used as a novel biomarker for the diagnosis and treatment of LA.