TAp73 upregulates IL-1β in cancer cells: Potential biomarker in lung and breast cancer?

p73 activates transcriptional signatures of basal lineage identity and ciliogenesis in pancreatic ductal adenocarcinoma

During the progression of pancreatic ductal adenocarcinoma (PDAC), tumor cells are known to acquire transcriptional and morphological properties of the basal (also known as squamous) epithelial lineage, which leads to more aggressive disease characteristics. Here, we show that a subset of basal-like PDAC tumors aberrantly express p73 (TA isoform), which is a known transcriptional activator of basal lineage identity, ciliogenesis, and tumor suppression in normal tissue development. Using gain- and loss- of function experiments, we show that p73 is necessary and sufficient to activate genes related to basal identity (e.g. KRT5), ciliogenesis (e.g. FOXJ1), and p53-like tumor suppression (e.g. CDKN1A) in human PDAC models. Owing to the paradoxical combination of oncogenic and tumor suppressive outputs of this transcription factor, we propose that PDAC cells express a low level of p73 that is optimal for promoting lineage plasticity without severe impairment of cell proliferation. Collectively, our study reinforces how PDAC cells exploit master regulators of the basal epithelial lineage during disease progression.

Pathogenetic role and clinical significance of interleukin-1β in cancer

In recent years, pro-oncogenic mechanisms of the tumour microenvironment (ТМЕ) have been actively discussed. One of the main cytokines of the TМЕ is interleukin-1 beta (IL-1β), which exhibits proinflammatory properties. Some studies have shown an association between an increase in IL-1β levels and tumour progression. The purpose of this review is to analyse the pathogenic mechanisms induced by IL-1β in the TМЕ, as well as the diagnostic significance of the presence of IL-1β in patients with cancer and the efficacy of treatment with IL-1β inhibitors. According to the literature, IL-1β can induce an increase in tumour angiogenesis due to its effects on the differentiation of epithelial cells, pro-angiogenic molecule secretion and expression of adhesion molecules, thus increasing tumour growth and metastasis. IL-1β is also involved in the suppression of anti-tumour immune responses. The expression and secretion of IL-1β has been noted in various types of tumours. In some clinical studies, an elevated level of IL-1β was found to be associated with low efficacy of anti-cancer therapy and a poor prognosis. In most experimental and clinical studies, the use of IL-1β inhibitors contributed to a decrease in tumour mass and an increase in the response to anti-tumour drugs.

p73 isoforms meet evolution of metastasis

Cancer largely adheres to Darwinian selection. Evolutionary forces are prominent during metastasis, the final and incurable disease stage, where cells acquire combinations of advantageous phenotypic features and interact with a dynamically changing microenvironment, in order to overcome the metastatic bottlenecks, while therapy exerts additional selective pressures. As a strategy to increase their fitness, tumors often co-opt developmental and tissue-homeostasis programs. Herein, 25 years after its discovery, we review TP73, a sibling of the cardinal tumor-suppressor TP53, through the lens of cancer evolution. The TP73 gene regulates a wide range of processes in embryonic development, tissue homeostasis and cancer via an overwhelming number of functionally divergent isoforms. We suggest that TP73 neither merely mimics TP53 via its p53-like tumor-suppressive functions, nor has black-or-white-type effects, as inferred by the antagonism between several of its isoforms in processes like apoptosis and DNA damage response. Rather, under dynamic conditions of selective pressure, the various p73 isoforms which are often co-expressed within the same cancer cells may work towards a common goal by simultaneously activating isoform-specific transcriptional and non-transcriptional programs. Combinatorial co-option of these programs offers selective advantages that overall increase the likelihood for successfully surpassing the barriers of the metastatic cascade. The p73 functional pleiotropy-based capabilities might be present in subclonal populations and expressed dynamically under changing microenvironmental conditions, thereby supporting clonal expansion and propelling evolution of metastasis. Deciphering the critical p73 isoform patterns along the spatiotemporal axes of tumor evolution could identify strategies to target TP73 for prevention and therapy of cancer metastasis.

A Novel Inflammatory Response-Related Gene Signature Predicts Immune Status and Prognosis of Breast Cancer

PURPOSE

Breast cancer is the most common type of cancer and the leading cause of cancer-related death in women worldwide. In this study, we aimed to construct an inflammatory response-related gene model for predicting the immune status and prognosis of breast cancer patients.

METHODS

We obtained the inflammatory response-related genes from the Molecular Signatures Database. Furthermore, we used univariate Cox regression analysis, the least absolute shrinkage and selection operator (LASSO) regression analysis, and multivariate Cox regression to construct an inflammatory response-related gene signature (IRGS) model based on dataset obtained from The Cancer Genome Atlas (TCGA). Patients were consequently categorized into high-risk and low-risk groups. Kaplan-Meier analysis was used to compare the overall survival (OS) of high-risk and low-risk groups. Following that, we validated the model using a dataset (GSE96058) acquired from Gene Expression Omnibus (GEO) database. Univariate and multivariate Cox analyses were used to determine the independent prognostic value of the IRGS in the TCGA and GSE96058 cohorts. A nomogram was constructed to predict the OS in the TCGA cohort. Further, we used Gene Set Enrichment Analysis (GSEA), CIBERSORT, and single-sample Gene Set Enrichment Analysis (ssGSEA) to evaluate the associations of IRGS with immune-associated pathways and immune infiltration. Finally, the relationship between the expression of the signature genes and drug sensitivity was conducted using Pearson correlation analysis.

RESULTS

We established an IRGS to stratify breast cancer patients into the low-risk and high-risk groups. In both the training and validation sets, patients in the high-risk group had significantly shorter OS than those in the low-risk group. The risk score was significantly correlated with the clinical characteristics and could be used as a tool to predict the prognosis of breast cancer. Moreover, we found that the IRGS risk score was an independent predictor of OS in breast cancer patients, and a nomogram model based on IRGS risk score and other clinical factors could effectively predict the prognosis of breast cancer patients. Furthermore, the IRGS risk score was correlated with immune characteristics and was inversely associated with the abundance of immune cell infiltration. Patients with a low IRGS risk score had higher expression levels of immune checkpoint genes, suggesting that IRGS can be used as a potential indicator for immunotherapy. Finally, we found that the expression levels of prognostic genes were significantly correlated with tumor cell sensitivity to chemotherapeutic drugs.

CONCLUSION

Overall, these findings suggest that the IRGS can be used to predict the prognosis and immune status of breast cancer patients and provide new therapeutic targets for the treatment of these patients.

Long non-coding RNAs affecting cell metabolism in cancer

Metabolic reprogramming is commonly recognized as one important hallmark of cancers. Cancer cells present significant alteration of glucose metabolism, oxidative phosphorylation, and lipid metabolism. Recent findings demonstrated that long non-coding RNAs control cancer development and progression by modulating cell metabolism. Here, we give an overview of breast cancer metabolic reprogramming and the role of long non-coding RNAs in driving cancer-specific metabolic alteration.

Circ_0004354 might compete with circ_0040039 to induce NPCs death and inflammatory response by targeting miR-345-3p-FAF1/TP73 axis in intervertebral disc degeneration

The abnormal function of nucleus pulposus cells (NPCs) plays a crucial role in the pathogenesis of intervertebral disc degeneration (IVDD). Recent studies have demonstrated that circular RNAs (circRNAs) are involved in the pathological process of IVDD by regulating NPCs' function. Nevertheless, the investigation on circRNA-circRNA interaction has not yet been reported. Here, we identified the top upregulated circ_0040039 and circ_0004354 in IVDD, derived from the syntrophin beta 2 gene but had different degrees of biological functions. Accumulating studies have reported PANoptosis is composed of apoptosis, pyroptosis, and necroptosis. Based on this, we think there should be a new pro-inflammatory cell death PAoptosis in the form of apoptosis and pyroptosis. Circ_0004354 might compete with circ_0040039 to induce the development of IVDD by modulating miR-345-3p-FAF1/TP73 axis-mediated PAoptosis, inflammatory response, growth inhibition, and ECM degradation of NPCs. Thus, these findings offer a novel insight into the circRNAs-mediated posttranscriptional regulatory network in IVDD, contributing to further clarification of the pathological mechanism of IVDD to develop a promising therapeutic target for IVDD diseases.

Role of Interleukin-1 in the pathogenesis of colorectal cancer: A brief look at anakinra therapy

Colorectal cancer (CRC) is known as one of the deadliest and most common cancers globally and causes nearly one million cancer deaths yearly. Like many malignancies, the immune system and its components play a crucial role in the pathogenesis of CRC. As multifunction mediators of the immune system, cytokines are involved in several inflammatory and anti-inflammatory responses. Interleukin-1 (IL-1) belongs to a family of 11 members and is involved in inflammatory responses. Beyond its biological role as a mediator of innate immune responses, it is also seen in chronic stress and inflammation and numerous pathological states. The role of IL-1 in malignancies can also be very significant because it has recently been shown that this cytokine can also be secreted from tumor cells and induce the recruitment of myeloid-derived immunosuppressive cells. As a result, the tumor microenvironment (TME) is affected and, despite being inflammatory, causes the onset and progression of tumor cells. Since surgery and chemotherapy are the first choices to treat patients with cancer, especially CRC, it is usually not well-prognosed, particularly in patients with metastatic lesions CRC. Therefore, targeted therapy may prolong the overall survival of CRC patients. Furthermore, evidence shows that anakinra has had satisfactory results in treating CRC. Therefore, this review summarized the role of IL-1 in the pathogenesis of CRC as well as immunotherapy based on inhibition of this cytokine in this type of cancer.

Dual Role of p73 in Cancer Microenvironment and DNA Damage Response

Understanding the mechanisms that regulate cancer progression is pivotal for the development of new therapies. Although p53 is mutated in half of human cancers, its family member p73 is not. At the same time, isoforms of p73 are often overexpressed in cancers and p73 can overtake many p53 functions to kill abnormal cells. According to the latest studies, while p73 represses epithelial–mesenchymal transition and metastasis, it can also promote tumour growth by modulating crosstalk between cancer and immune cells in the tumor microenvironment, M2 macrophage polarisation, Th2 T-cell differentiation, and angiogenesis. Thus, p73 likely plays a dual role as a tumor suppressor by regulating apoptosis in response to genotoxic stress or as an oncoprotein by promoting the immunosuppressive environment and immune cell differentiation.

The p53 family member p73 in the regulation of cell stress response

During oncogenesis, cells become unrestrictedly proliferative thereby altering the tissue homeostasis and resulting in subsequent hyperplasia. This process is paralleled by resumption of cell cycle, aberrant DNA repair and blunting the apoptotic program in response to DNA damage. In most human cancers these processes are associated with malfunctioning of tumor suppressor p53. Intriguingly, in some cases two other members of the p53 family of proteins, transcription factors p63 and p73, can compensate for loss of p53. Although both p63 and p73 can bind the same DNA sequences as p53 and their transcriptionally active isoforms are able to regulate the expression of p53-dependent genes, the strongest overlap with p53 functions was detected for p73. Surprisingly, unlike p53, the p73 is rarely lost or mutated in cancers. On the contrary, its inactive isoforms are often overexpressed in cancer. In this review, we discuss several lines of evidence that cancer cells develop various mechanisms to repress p73-mediated cell death. Moreover, p73 isoforms may promote cancer growth by enhancing an anti-oxidative response, the Warburg effect and by repressing senescence. Thus, we speculate that the role of p73 in tumorigenesis can be ambivalent and hence, requires new therapeutic strategies that would specifically repress the oncogenic functions of p73, while keeping its tumor suppressive properties intact.

Key Factor Regulating Inflammatory Microenvironment, Metastasis, and Resistance in Breast Cancer: Interleukin-1 Signaling

Breast cancer is one of the top-ranked cancers for incidence and mortality worldwide. The biggest challenges in breast cancer treatment are metastasis and drug resistance, for which work on molecular evaluation, mechanism studies, and screening of therapeutic targets is ongoing. Factors that lead to inflammatory infiltration and immune system suppression in the tumor microenvironment are potential therapeutic targets. Interleukin-1 is known as a proinflammatory and immunostimulatory cytokine, which plays important roles in inflammatory diseases. Recent studies have shown that interleukin-1 cytokines drive the formation and maintenance of an inflammatory/immunosuppressive microenvironment through complex intercellular signal crosstalk and tight intracellular signal transduction, which were found to be potentially involved in the mechanism of metastasis and drug resistance of breast cancer. Some preclinical and clinical treatments or interventions to block the interleukin-1/interleukin-1 receptor system and its up- and downstream signaling cascades have also been proven effective. This study provides an overview of IL-1-mediated signal communication in breast cancer and discusses the potential of IL-1 as a therapeutic target especially for metastatic breast cancer and combination therapy and current problems, aiming at enlightening new ideas in the study of inflammatory cytokines and immune networks in the tumor microenvironment.

Expression of inflammatory interleukins and selected miRNAs in non-small cell lung cancer

Tumours are characterised by an ability to avoid immune destruction and the presence of cancer-associated inflammation. Better understanding of the link between lung cancer and such inflammation is vital for early detection and personalized treatment. Thus, we examined the mRNA expression of interleukins IL-1β, IL-6, IL-17 and miR-9, miR-122 as potential useful biomarkers of NSCLC. Tumour tissues, non-cancerous tissue and blood samples were collected from 39 patients with primary NSCLC undergoing surgical treatment. The selected RNA was isolated from tissue samples and selected miRNAs from peripheral blood exosomes. This RNA was transcribed to cDNA and quantified using RT-qPCR. Significantly higher expression of the selected interleukins was observed in non-cancerous than tumour tissue, and IL-6 was significantly higher in the tumour tissue of patients with a history of ≤ 40 pack-years (PYs) (2.197, IQR: 0.821-4.415) than in those with > 40 PYs (0.461, IQR: 0.372-0.741; p = 0.037). It is clear that inflammatory processes play a role in NSCLC, as indicated by the upregulation of IL-1β and IL-6 in tumour and adjacent tissue, and that smoking has a strong influence on inflammation in tumourigenesis, demonstrated by the upregulation of IL-6 in tumour samples among patients with ≤ 40 PYs compared to > 40 PYs.

Interleukin-1β weakens paclitaxel sensitivity through regulating autophagy in the non-small cell lung cancer cell line A549

Non-small cell lung cancer (NSCLC) poses a threat to human health and paclitaxel chemotherapy has been approved for the treatment of this type of cancer. However, resistance to treatment severely compromises the survival rate and prognosis of patients with NSCLC. The aim of the present study was to investigate the role of IL-1β in paclitaxel sensitivity of NSCLC cells and elucidate the underlying mechanism. The expression of IL-1β was found to be upregulated in NSCLC tissues and cells compared with healthy adjacent tissues and a normal epithelial cell line, respectively, as detected by reverse transcription-quantitative PCR and western blot analyses. Subsequently, Cell Counting Kit-8 assay and flow cytometry revealed that IL-1β weakened the sensitivity of A549 cells to paclitaxel. It was subsequently demonstrated that IL-1β induced A549 cell autophagy, while tunicamycin-induced autophagy increased the IL-1β expression level and weakened paclitaxel sensitivity. Thus, the results revealed that IL-1β reduced the sensitivity to paclitaxel in A549 cells by promoting autophagy and suggested that IL-1β may be of value for improving the therapeutic efficacy of paclitaxel chemotherapy in NSCLC.

[Alkaline processing of cantharidin can significanty improve the antitumor activity of cantharidin]

OBJECTIVE

To assess the changes in the effects of cantharides after alkaline processing on proliferation, migration, invasion, and apoptosis of human lung cancer A549 cells.

METHODS

Human non-small cell lung cancer A549 cells were treated with cantharis extract (CTE) from raw cantharides and alkali processed cantharis extract (ACE). The proliferation of the cells was detected with CCK-8 assay, and the cell migration and invasion were assessed using wound healing assay and Transwell assay, respectively. The expressions of MMP1 and MMP2 in the cells were detected using Western blotting, the contents of IFN-γ, IL-1β and TNF-α were measured with ELISA, and cell apoptosis was analyzed with annexinV/PI fluorescent staining.

RESULTS

Both CTE and ACE significantly reduced the viability and inhibited the migration of A549 cells, and high-dose ACE produced a significantly stronger inhibitory effect on cell migration than high- dose CTE (P < 0.01). ACE showed more potent inhibitory effect than CTE on the invasion of A549 cells (P < 0.01). Both CTE and ACE inhibited the expressions of MMP1 and MMP2 and up-regulated the level of IFN-γ without significantly affecting the levels of IL-1β and TNF-α. Annexin V/PI staining showed that both CTE and ACE caused apoptosis of A549 cells, but ACE had a stronger proapoptotic effect.

CONCLUSIONS

Processing with sodium hydroxide can significantly improve the antitumor activity of cantharides, which inhibits the proliferation, migration and invasion of A549 cells possibly by down-regulating the expressions of MMP1 and MMP2, promoting apoptosis and increasing the level of IFN-γ.

Interleukin-1β and Cancer

Within a tumor, IL-1β is produced and secreted by various cell types, such as immune cells, fibroblasts, or cancer cells. The IL1B gene is induced after "priming" of the cells and a second signal is required to allow IL-1β maturation by inflammasome-activated caspase-1. IL-1β is then released and leads to transcription of target genes through its ligation with IL-1R1 on target cells. IL-1β expression and maturation are guided by gene polymorphisms and by the cellular context. In cancer, IL-1β has pleiotropic effects on immune cells, angiogenesis, cancer cell proliferation, migration, and metastasis. Moreover, anti-cancer treatments are able to promote IL-1β production by cancer or immune cells, with opposite effects on cancer progression. This raises the question of whether or not to use IL-1β inhibitors in cancer treatment.

TAp73 regulates ATP7A: possible implications for ageing-related diseases

The p53 family member p73 controls a wide range of cellular function. Deletion of p73 in mice results in increased tumorigenesis, infertility, neurological defects and altered immune system. Despite the extensive effort directed to define the molecular underlying mechanism of p73 function a clear definition of its transcriptional signature and the extent of overlap with the other p53 family members is still missing. Here we describe a novel TAp73 target, ATP7A a member of a large family of P-type ATPases implicated in human neurogenerative conditions and cancer chemoresistance. Modulation of TAp73 expression influences basal expression level of ATP7A in different cellular models and chromatin immunoprecipitation confirmed a physical direct binding of TAp73 on ATP7A genomic regions. Bioinformatic analysis of expression profile datasets of human lung cancer patients suggests a possible implication of TAp73/ATP7A axis in human cancer. These data provide a novel TAp73-dependent target which might have implications in ageing-related diseases such as cancer and neurodegeneration.

Endothelin Signaling Contributes to Modulation of Nociception in Early-stage Tongue Cancer in Rats

BACKGROUND

Patients with early stage tongue cancer do not frequently complain of tongue pain. Endothelin-1 signaling is upregulated in the cancerous tongue at the early stage. We tested the hypothesis that endothelin-1 signaling contributes to the modulation of tongue nociception.

METHODS

Squamous cell carcinoma cells were inoculated into the tongue under general anesthesia. Lingual mechanical sensitivity under light anesthesia using forceps from days 1 to 21 (n = 8) and the amounts of endothelin-1 and β-endorphin in the tongue on days 6, 14, and 21 (n = 5 to 7) were examined after the inoculation. The effect of endothelin-A or µ-opioid receptor antagonism on the mechanical sensitivity was examined (n = 5 to 7).

RESULTS

Lingual mechanical sensitivity did not change at the early stage (days 5 to 6) but increased at the late stage (days 13 to 14). The amount of endothelin-1 increased (25.4 ± 4.8 pg/ml vs. 15.0 ± 5.2 pg/ml; P = 0.008), and endothelin-A receptor antagonism in the tongue induced mechanical hypersensitivity at the early stage (51 ± 9 g vs. 81 ± 6 g; P = 0.0001). The µ-opioid receptor antagonism enhanced mechanical hypersensitivity (39 ± 7 g vs. 81 ± 6 g; P < 0.0001), and the amount of β-endorphin increased at the early stage.

CONCLUSIONS

β-Endorphin released from the cancer cells via endothelin-1 signaling is involved in analgesic action in mechanical hypersensitivity at the early stage.

Helicobacter pylori-induced YAP1 nuclear translocation promotes gastric carcinogenesis by enhancing IL-1β expression

Gastric cancer (GC) is one of the most common and malignant pathologies, and a significant portion of GC incidences develops from Helicobacter pylori (Hp)-induced chronic gastritis. Although the exact mechanisms of GC are complex and poorly understood, gastric carcinogenesis is a good model to investigate how inflammation and infection collaboratively promote tumorigenesis. Yes-associated protein 1 (YAP1) is the key effector of the Hippo pathway, which is silenced in most human cancers. Herein, we verified the tumor-promoting effect of YAP1 in vitro, in vivo, and in human specimens. We revealed that YAP1 displays nuclear translocation and works with TEAD to activate transcription of the crucial inflammatory cytokine IL-1β in gastric cells infected with Hp. As IL-1ß accounts for inflammation-associated tumorigenesis, this process can lead to gastric carcinogenesis. Thus, in addition to activating proliferation genes, YAP1 also plays a major role in inflammation amplification by activating inflammatory cytokine genes. Excitingly, our research demonstrates that transfection of mutant plasmid YAP-5SA/S94A or addition of the drug verteporfin, both of which are thought to disrupt the YAP1-TEAD interaction, can arrest the carcinogenesis process. These findings can provide new approaches to GC treatment.

Restoration of Peripheral Intermediate and Classical Monocytes Expressing HLA-DR in Patients With Lung Adenocarcinoma After Platinum-Based Chemotherapy

Lung adenocarcinoma represents one of the lung cancer subtypes with major prevalence. Accumulating evidence indicates that the immune system plays an important role in the evolution of the neoplastic process; additionally, several reports suggest that chemotherapy has an immunomodulatory effect. In order to identify the peripheral subpopulations of leukocytes that may change after chemotherapy, we evaluated several peripheral immune subpopulations of monocytes and lymphocytes by multicolor flow cytometry. In addition, we also measured cytokines and growth factors on plasma in order to evaluate the pro-inflammatory context in patients with lung adenocarcinoma after chemotherapy. We found that HLA-DR⁺ classical and intermediate monocytes were decreased in patients before chemotherapy, compared to controls. After chemotherapy, the relative percentage of those subpopulations was restored. In addition, interleukin 1β, interleukin 12, and interleukin 5 were increased after chemotherapy compared to prechemotherapy levels, while MIP-1β was decreased.

Sustained protein synthesis and reduced eEF2K levels in TAp73-\- mice brain: a possible compensatory mechanism

The transcription factor p73 is a member of the p53 family, of which the transactivation domain containing isoform (TAp73) plays key roles in brain development and neuronal stem cells. TAp73 also facilitates homoeostasis and prevents oxidative damage in vivo by inducing the expression of its target genes. Recently, we found that in addition to its role in regulation of transcription, TAp73 also affects mRNA translation. In cultured cells, acute TAp73 depletion activates eEF2K, which phosphorylates eEF2 reducing mRNA translation elongation. As a consequence, there is a reduction in global proteins synthesis rates and reprogramming of the translatome, leading to a selective decrease in the translation of rRNA processing factors. Given the dramatic effects of Tap73 depletion in vitro it was important to determine whether similar effects were observed in vivo. Here, we report the surprising finding that in brains of TAp73 KO mice there is a reduced level of eEF2K, which allows protein synthesis rates to be maintained suggesting a compensation model. These data provide new insights to the role of TAp73 in translation regulation and the eEF2K pathway in the brain.

The Role of Interleukin-1 in the Pathogenesis of Cancer and its Potential as a Therapeutic Target in Clinical Practice

Interleukin-1 (IL-1) has long been known to be a key mediator of immunity and inflammation. Its dysregulation has been implicated in recent years in tumorigenesis and tumor progression, and its upregulation is thought to be associated with many tumors. Overexpression of the IL-1 agonists IL-1α and IL-1β has been shown to promote tumor invasiveness and metastasis by inducing the expression of angiogenic genes and growth factors. IL-1 blockers such as anakinra and canakinumab are already approved and widely used for the treatment of some autoimmune and autoinflammatory diseases and are currently being tested in preclinical and human clinical trials for cancer therapy. In this paper we review the most recent discoveries regarding the association between IL-1 dysregulation and cancer and present the novel IL-1 blockers currently being tested in cancer therapy and their corresponding clinical trials.

DLC2 inhibits development of glioma through regulating the expression ratio of TAp73α/TAp73β

To date, the anti-tumor mechanism of the deleted in liver cancer 2 (DLC2) in gliomas is still unclear. The study shows that TAp73α expression and TAp73α/TAp73β ratio are frequently high in gliomas and that TAp73α and TAp73β have opposite roles in regulating proliferation and apoptosis of glioma cells. Moreover, DLC2 is low-expressed in gliomas, which negatively correlates with TAp73α expression and TAp73α/TAp73β ratio. More importantly, DLC2 inhibits development of glioma by decreasing expression of TAp73α, which changes the expression ratio of TAp73α/TAp73β in glioma cells. Mechanically, DLC2 interacts directly with TAp73α and induces TAp73α ubiquitination and degradation, which is mediated through SAM domain of DLC2 and TAp73α. In detail, DLC2 with SAM domain deletion fails to interact with TAp73α and induce TAp73α ubiquitination and degradation, and SAM deletion decreased tumorigenesis-inhibition effect of DLC2. In conclusion, DLC2 inhibits glioma development by inducing TAp73α degradation and subsequent change of TAp73α/TAp73β expression ratio.