CIP2A is associated with multidrug resistance in cervical adenocarcinoma by a P-glycoprotein pathway

Research progress of metabolomics in cervical cancer

INTRODUCTION

Cervical cancer threatens women's health seriously. In recent years, the incidence of cervical cancer is on the rise, and the age of onset tends to be younger. Prevention, early diagnosis and specific treatment have become the main means to change the prognosis of cervical cancer patients. Metabolomics research can directly reflect the changes of biochemical processes and microenvironment in the body, which can provide a comprehensive understanding of the changes of metabolites in the process of disease occurrence and development, and provide new ways for the prevention and diagnosis of diseases.

OBJECTIVES

The aim of this study is to review the metabolic changes in cervical cancer and the application of metabolomics in the diagnosis and treatment.

METHODS

PubMed, Web of Science, Embase and Scopus electronic databases were systematically searched for relevant studies published up to 2022.

RESULTS

With the emergence of metabolomics, metabolic regulation and cancer research are further becoming a focus of attention. By directly reflecting the changes in the microenvironment of the body, metabolomics research can provide a comprehensive understanding of the patterns of metabolites in the occurrence and development of diseases, thus providing new ideas for disease prevention and diagnosis.

CONCLUSION

With the continuous, in-depth research on metabolomics research technology, it will bring more benefits in the screening, diagnosis and treatment of cervical cancer with its advantages of holistic and dynamic nature.

From Basic Science to Clinical Practice: The Role of Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A)/p90 in Cancer

Cancerous inhibitor of protein phosphatase 2A (CIP2A), initially reported as a tumor-associated antigen (known as p90), is highly expressed in most solid and hematological tumors. The interaction of CIP2A/p90, protein phosphatase 2A (PP2A), and c-Myc can hinder the function of PP2A toward c-Myc S62 induction, thus stabilizing c-Myc protein, which represents a potential role of CIP2A/p90 in tumorigeneses such as cell proliferation, invasion, and migration, as well as cancer drug resistance. The signaling pathways and regulation networks of CIP2A/p90 are complex and not yet fully understood. Many previous studies have also demonstrated that CIP2A/p90 can be used as a potential therapeutic cancer target. In addition, the autoantibody against CIP2A/p90 in sera may be used as a promising biomarker in the diagnosis of certain types of cancer. In this Review, we focus on recent advances relating to CIP2A/p90 and their implications for future research.

SP1-induced lncRNA DUBR promotes stemness and oxaliplatin resistance of hepatocellular carcinoma via E2F1-CIP2A feedback

Oxaliplatin-based chemotherapy is widely used to treat advanced hepatocellular carcinoma (HCC), but many patients develop drug resistance that leads to tumor recurrence. Cancer stem cells (CSCs) are known to contribute to chemoresistance, the underlying mechanism, however, remains largely unknown. In this study, we discovered a specificity protein 1 (SP1)-induced long noncoding RNA--DPPA2 upstream binding RNA (DUBR) and its high expression in HCC tissues and liver CSCs. DUBR was associated with HCC progression and poor chemotherapy response. Moreover, DUBR facilitated the stemness and oxaliplatin resistance of HCC in vitro and in vivo. Mechanistically, DUBR upregulated cancerous inhibitor of protein phosphatase 2A (CIP2A) expression through E2F1-mediated transcription regulation. DUBR also exerted function by binding microRNA (miR)-520d-5p as a competing endogenous RNA to upregulate CIP2A at mRNA level. CIP2A, in turn, stabilized E2F1 protein and activated the Notch1 signaling pathway, thereby increasing the stemness feature of HCC and leading to chemoresistance. In conclusion, we identified SP1/DUBR/E2F1-CIP2A as a critical axis to activate the Notch1 signaling pathway and promote stemness and chemoresistance of HCC. Therefore, DUBR could be a potential target in HCC treatment.

PP2A: A Promising Biomarker and Therapeutic Target in Endometrial Cancer

Over the last decade, the use of targeted therapies has immensely increased in the treatment of cancer. However, treatment for endometrial carcinomas (ECs) has lagged behind, although potential molecular markers have been identified. This is particularly problematic for the type II ECs, since these aggressive tumors are usually not responsive toward the current standard therapies. Therefore, type II ECs are responsible for most EC-related deaths, indicating the need for new treatment options. Interestingly, molecular analyses of type II ECs have uncovered frequent genetic alterations (up to 40%) in PPP2R1A, encoding the Aα subunit of the tumor suppressive heterotrimeric protein phosphatase type 2A (PP2A). PPP2R1A mutations were also reported in type I ECs and other common gynecologic cancers, albeit at much lower frequencies (0-7%). Nevertheless, PP2A inactivation in the latter cancer types is common via other mechanisms, in particular by increased expression of Cancerous Inhibitor of PP2A (CIP2A) and PP2A Methylesterase-1 (PME-1) proteins. In this review, we discuss the therapeutic potential of direct and indirect PP2A targeting compounds, possibly in combination with other anti-cancer drugs, in EC. Furthermore, we investigate the potential of the PP2A status as a predictive and/or prognostic marker for type I and II ECs.

Cancerous inhibitor of protein phosphatase 2A regulates cisplatin resistance in ovarian cancer

Ovarian cancer is the most aggressive type of gynecological cancer. The cause of the poor survival rate is the development of chemotherapy resistance to platinum-based therapies, including cisplatin. The present study aimed to investigate the mechanism of cancerous inhibitor of protein phosphatase 2A (CIP2A)-induced chemoresistance in ovarian cancer. The present study initially investigated the expression of CIP2A in the ovarian tumor tissue, cisplatin-sensitive SKOV-3 cell line, and cisplatin-resistant ovarian carcinoma SKOV-3CDDP/R cell line. In addition, CIP2A was knocked down using small interference RNA in ovarian cancer cells and the chemosensitivity of these cells was analyzed. The results demonstrated that CIP2A expression was significantly higher in patients with ovarian cancer and in the cisplatin-resistant ovarian carcinoma SKOV-3CDDP/R cell line at the mRNA and protein levels. The proliferation and chemosensitivity were decreased and enhanced, respectively, when CIP2A was knocked down. CIP2A silencing significantly promoted the apoptosis induced by cisplatin in SKOV-3CDDP/R cells, suggesting that CIP2A participated in the cisplatin resistance of ovarian cancer cells and that CIP2A silencing enhanced the apoptosis induced by cisplatin. CIP2A may be considered as a potential candidate for modulating cisplatin therapy in ovarian cancer.

Forskolin increases the effect of everolimus on aromatase inhibitor-resistant breast cancer cells

Aromatase inhibitor (AI) resistance is a major obstacle in the treatment of estrogen receptor-positive breast cancer. Everolimus (EVE) ameliorates AI-resistant breast cancer and is therefore used in cancer treatment. However, some patients show resistance to EVE. Here, we used 30 clones of long-term estrogen-deprived (LTED) MCF-7 cells as a model of AI-resistant breast cancer. We examined changes in protein phosphatase type 2A (PP2A) and cancerous inhibitor of PP2A (CIP2A), a negative regulator of PP2A, in LTED cells treated with EVE. In LTED cells with high sensitivity to EVE, CIP2A expression decreased at low EVE concentrations; however, in LTED cells poorly sensitive to EVE, CIP2A and PP2A did not change upon exposure to EVE. Therefore, we hypothesized that there is a relation between expression of CIP2A and sensitivity to EVE. Knockdown of CIP2A increased the sensitivity to EVE in three clones poorly sensitive to EVE. Additionally, we found that treatment with FSK, which activates PP2A, increased the sensitivity of the cells to EVE. Our data point to CIP2A and PP2A as novel therapeutic targets for AI-resistant breast cancer.

MicroRNA-383-5p acts as a prognostic marker and inhibitor of cell proliferation in lung adenocarcinoma by cancerous inhibitor of protein phosphatase 2A

Lung cancer is the leading cause of cancer-associated mortality worldwide. MicroRNAs (miRNAs/miRs) serve a role in the occurrence and development of lung cancer. The aim of the present study was to analyze the expression and function of the proliferation-associated miR-383-5p in lung adenocarcinoma (LAC). Samples of human LAC and matched adjacent normal lung tissues were surgically removed, and miR-383-5p expression and the pathological characteristics of lung adenocarcinoma were investigated. The present study revealed that miR-383-5p expression level was significantly decreased in LAC tissues and its expression levels were markedly associated with tumor size and differentiation. Overexpression of miR-383-5p in A549 and H1299 LAC cell lines inhibited cell proliferation by G₁ cell cycle phase arrest and induction of apoptosis. Cancerous inhibitor of protein phosphatase 2A (CIP2A), a potential target gene of miR-383-5p, was inversely associated with miR-383-5p expression level in LAC tissues and cell lines. Furthermore, the results of the present study demonstrated that CIP2A was directly regulated by miR-383-5p and the restoration of CIP2A expression reversed the inhibitory effects of miR-383-5p on LAC cell proliferation. In conclusion, the results of the present study demonstrated that miR-383-5p was downregulated in LAC tissues. By targeting CIP2A, miR-383-5p exerts its anti-proliferative function in LAC, suggesting its use a potential novel potential prognostic biomarker and therapeutic target for LAC.

Spectral mapping of 3D multi-cellular tumor spheroids: time-resolved confocal microscopy

The tumor micro-environment of 3D multicellular spheroids and their interaction with a drug molecule are studied using time resolved confocal microscopy.