Differential Expression of MicroRNAs in Uterine Cervical Cancer and Its Implications in Carcinogenesis; An Integrative Approach

Role of Phosphatidylinositol 3-Kinase and Its Catalytic Unit PIK3CA in Cervical Cancer: A Mini-Review

In complicated disorders like cancer, signaling pathways form a tangled network. Targeting one gene may result in an unfavorable reaction from another off-target gene. Such entwined complexities may result in treatment resistance or failure in cancer patients. The PI3K/Akt/mTOR (phosphoinositol 3-kinase/protein kinase B/mammalian target of rapamycin) pathway is dysregulated in cervical cancer and is used as a biomarker for therapy. PI3K is a kinase that consists of a regulatory and catalytic domain and has phosphorylation capability. Class I components like the catalytic part (PIK3CA and PIK3CD) and regulatory part (like PIK3R1, PIK3R2, PIK3R3, and PIK3R5) are associated with oncogenesis and growth factors in cervical cancer. This review is aimed at discussing the involvement of the PI3K component of the PI3K/Akt/mTOR network in cervical cancer. Specifically, class I catalytic subunit PIK3CA has been identified as a pharmacological target, making it therapeutically significant. Apart from discussing the function of PI3K and PIK3CA in cervical cancer, we also discuss their inhibitors, which may be beneficial in treating cervical cancer.

Anti-Programmed Death Protein-1 (PD-1) Antibody Combined with Paclitaxel Exert Anti-Cancer Effect on Cervical Cancer Cells

The therapeutic effect of combined drugs on cervical cancer has been confirmed. Whether anti-PD-1 antibody combined with paclitaxel mediates the PI3K-Akt pathway to regulate cervical cancer still requires further research. 20 nude mice received subcutaneous administration of Hela cells to establish cervical cancer model which was then assigned into blank control group, control group A (PD-1 antibody (5 mg/ kg) administration), control group B (paclitaxel), and observation group (PD-1 antibody combined with paclitaxel) followed by analysis of cell proliferation, apoptosis, expression of PI3K-Akt signaling proteins and mRNAs. Observation group had lowest tumor size, highest cell proliferation inhibition rate and apoptosis, which were all reversed in blank group with a largest tumor size, lowest cell proliferation inhibition rate and cell apoptosis. There were no differences between control group A and control group B (P > 0.05). The expressions of PI3K, Akt, p53, and p21 proteins were lowest in observation group and highest in blank group. In addition, control group showed no difference to control group B (P > 0.05). In conclusion, anti-PD-1 antibody combined with paclitaxel inhibits PI3K-Akt signaling activity, thereby downregulating PI3K, Akt, p53, and p21 protein, controlling cervical cancer cell division, promoting cell apoptosis, and exerting anti-tumor effects.

CircMYBL2 regulates the resistance of cervical cancer cells to paclitaxel via miR-665-dependent regulation of EGFR

Circular RNAs are considered to be associated with cancer resistance. This study aims to investigate the function and mechanism of circMYBL2 in paclitaxel (PTX) resistance of cervical cancer (CC). The expression of circMYBL2, miR-665 and epidermal growth factor receptor (EGFR) was investigated using quantitative real-time polymerase chain reaction assay. Cell viability, cell colony number, cell proliferation, apoptosis and lactate dehydrogenase (LDH) were detected by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, colony formation, 5-ethynyl-2'-deoxyuridine incorporation, flow cytometry and LDH release assays, respectively. The interaction between miR-665 and circMYBL2 or EGFR was confirmed by dual-luciferase reporter assay. The protein expression levels were quantified by western blot or immunohistochemistry assay. Mice xenograft models were constructed to investigate the effect of circMYBL2 on CC tumor growth. CircMYBL2 was upregulated in CC tissues and cells, especially in PTX-resistant CC tissues and cells, and it was a stable circRNA mainly distributed in the cytoplasm. CircMYBL2 could enhance the PTX resistance of CC cells in vitro and promote CC tumor growth in vivo. Mechanistically, circMYBL2 could inhibit the PTX sensitivity and promote cell malignant behaviors in PTX-sensitive and PTX-resistant CC cells via upregulating EGFR mediated by miR-665. CircMYBL2 played a positive role in the PTX resistance and malignant activities of PTX-sensitive and PTX-resistant CC cells by regulating the miR-665/EGFR network, providing a novel therapeutic strategy for the treatment of CC patients resistant to PTX.

Silencing of hsa_circ_0009035 Suppresses Cervical Cancer Progression and Enhances Radiosensitivity through MicroRNA 889-3p-Dependent Regulation of HOXB7

Circular RNAs (circRNAs), a novel type of endogenous noncoding RNAs, have been identified as critical regulators in human carcinogenesis. Here, we investigated the precise actions of hsa_circ_0009035 in the progression and radioresistance of cervical cancer (CC). The levels of hsa_circ_0009035, microRNA 889-3p (miR-889-3p), and homeobox B7 (HOXB7) were detected by quantitative real-time PCR (qRT-PCR) or Western blotting. RNase R and actinomycin D assays were used to assess the stability of hsa_circ_0009035. Cell proliferation, cell cycle progression, apoptosis, migration, and invasion were gauged with Cell Counting Kit-8 (CCK-8), flow cytometry, and transwell assays. Cell colony formation and survival were determined by the colony formation assay. Targeted correlations among hsa_circ_0009035, miR-889-3p, and HOXB7 were examined by the dual-luciferase reporter, RNA immunoprecipitation (RIP), or RNA pulldown assay. Animal studies were performed to evaluate the impact of hsa_circ_0009035 on tumor growth. We found that hsa_circ_0009035 was highly expressed in CC tissues and cells, and it was associated with the radioresistance of CC patients. Moreover, the silencing of hsa_circ_0009035 inhibited CC cell proliferation, migration, invasion, and it enhanced apoptosis and radiosensitivity in vitro and weakened tumor growth in vivo. Mechanistically, hsa_circ_0009035 directly targeted miR-889-3p by binding to miR-889-3p, and hsa_circ_0009035 modulated HOXB7 expression through miR-889-3p. HOXB7 was a functional target of miR-889-3p in regulating CC progression and radioresistance in vitro, and hsa_circ_0009035 modulated CC progression and radioresistance in vitro by miR-889-3p. Our current study first identified hsa_circ_0009035 as an important regulator of CC progression and radioresistance at least in part through targeting the miR-889-3p/HOXB7 axis, highlighting its significance as a potential therapeutic target for CC treatment.

Genomic landscape analyses in cervical carcinoma and consequences for treatment

Where we are on the road to 'tailor-made' precision medicine for drug-resistant cervical carcinoma? We explored studies about analyses of viral and human genomes, epigenomes and transcriptomes, DNA mutation analyses, their importance in detecting HPV sequences, mechanisms of drug resistance to established and targeted therapies with small molecule or therapeutic antibodies, to radiosensitivity and to chemoradiotherapy. The value of repurposing of old drugs initially approved for other disease indications and now considered for cervix cancer therapy is also discussed. The microbiome influences drug response and survival too. HPV genomic integration sites were less significant. Nomograms (Lee et al., 2013) even outperformed FIGO staging regarding prediction of five-year overall survival times. We conclude that there are still many loose threads to be followed up, before coherent conclusions for individualized therapy of drug-resistant cervical carcinoma can be drawn.

Construction of ceRNA Coexpression Network and Screening of Molecular Targets in Colorectal Cancer

Objective

To screen some RNAs that correlated with colorectal cancer (CRC).

Methods

Differentially expressed miRNAs, lncRNAs, and mRNAs between cancer tissues and normal tissues in CRC were identified using data from the Gene Expression Omnibus (GEO) database. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and protein-protein interactions (PPIs) were performed to do the functional enrichment analysis. And a lncRNA-miRNA-mRNA network was constructed which correlated with CRC. RNAs in this network were subjected to analyze the relationship with the patient prognosis.

Results

A total of 688, 241, and 103 differentially expressed genes (diff-mRNA), diff-lncRNA, and diff-miRNA were obtained between cancer tissues and normal tissues. A total of 315 edges were obtained in the ceRNA network. lncRNA RP11-108K3.2 and mRNA ONECUT2 correlated with prognosis.

Conclusion

The identified RNAs and constructed ceRNA network could provide great sources for the researches of therapy of the CRC. And the lncRNA RP11-108K3.2 and mRNA ONECUT2 may serve as a novel prognostic predictor of CRC.

The Communication Between the PI3K/AKT/mTOR Pathway and Y-box Binding Protein-1 in Gynecological Cancer

Studies of the mechanistic (mammalian) target of rapamycin inhibitors (mTOR) represent a step towards the targeted treatment of gynecological cancers. It has been shown that women with increased levels of mTOR signaling pathway targets have worse prognosis compared to women with normal mTOR levels. Yet, targeting mTOR alone has led to unsatisfactory outcomes in gynecological cancer. The aim of our review was therefore to provide an overview of the most recent clinical results and basic findings on the interplay of mTOR signaling and cold shock proteins in gynecological malignancies. Due to their oncogenic activity, there are promising data showing that mTOR and Y-box-protein 1 (YB-1) dual targeting improves the inhibition of carcinogenic activity. Although several components differentially expressed in patients with ovarian, endometrial, and cervical cancer of the mTOR were identified, there are only a few investigated downstream actors in gynecological cancer connecting them with YB-1. Our analysis shows that YB-1 is an important player impacting AKT as well as the downstream actors interacting with mTOR such as epidermal growth factor receptor (EGFR), Snail or E-cadherin.

Human Papillomavirus Infections, Cervical Cancer and MicroRNAs: An Overview and Implications for Public Health

Human Papillomavirus (HPV) is among the most common sexually transmitted infections in both females and males across the world that generally do not cause symptoms and are characterized by high rates of clearance. Persistent infections due at least to twelve well-recognized High-Risk (HR) or oncogenic genotypes, although less frequent, can occur, leading to diseases and malignancies, principally cervical cancer. Three vaccination strategies are currently available for preventing certain HR HPVs-associated diseases, infections due to HPV6 and HPV11 low-risk types, as well as for providing cross-protection against non-vaccine genotypes. Nevertheless, the limited vaccine coverage hampers reducing the burden of HPV-related diseases globally. For HR HPV types, especially HPV16 and HPV18, the E6 and E7 oncoproteins are needed for cancer development. As for other tumors, even in cervical cancer, non-coding microRNAs (miRNAs) are involved in posttranscriptional regulation, resulting in aberrant expression profiles. In this study, we provide a summary of the epidemiological background for HPV occurrence and available immunization programs. In addition, we present an overview of the most relevant evidence of miRNAs deregulation in cervical cancer, underlining that targeting these biomolecules could lead to wide translational perspectives, allowing better diagnosis, prognosis and therapeutics, and with valuable applications in the field of prevention. The literature on this topic is rapidly growing, but advanced investigations are required to achieve more consistent findings on the up-regulated and down-regulated miRNAs in cervical carcinogenesis. Because the expression of miRNAs is heterogeneously reported, it may be valuable to assess factors and risks related to individual susceptibility.

A Functional Polymorphism in the Promoter of miR-17-92 is Associated with a Reduced Risk of Cervical Squamous Cell Carcinoma

miR-17-92 cluster was differentially expressed in cervical cancer, playing an important role in regulating cell proliferation, apoptosis, migration, and invasion. The purpose of this study was to investigate the association between polymorphisms (i.e., rs9588884, rs982873, and rs1813389) in the promoter of miR-17-92 and the risk of cervical squamous cell carcinoma (CSCC). The rs9588884 polymorphism was genotyped using a Taqman assay and the rs982873 and rs1813389 polymorphisms were genotyped using a polymerase chain reaction-restriction fragment length polymorphism method. The expression levels of miR-17-92 were determined using a quantitative PCR analysis. The rs9588884 GG genotype was associated with a reduced risk of CSCC in homozygote comparison (adjusted OR = 0.47, 95% CI, 0.30-0.75, P = 0.001), dominant model (adjusted OR = 0.67, 95% CI, 0.50-0.91, P = 0.01), and recessive model (adjusted OR = 0.57, 95% CI, 0.38-0.85, P = 0.01). The rs9588884 G allele was also associated with a reduced risk of CSCC in allele comparison (adjusted OR = 0.71, 95% CI, 0.58-0.88, P = 0.002). Moreover, patients with the rs9588884 GG genotype had lower levels of miR-20a compared with the rs9588884 CC genotype (P = 0.03). These findings indicate that the rs9588884 GG genotype was associated with lower levels of miR-20a and eventually related to the risk of CSCC in Chinese women.

Recent Advances on the Molecular Mechanism of Cervical Carcinogenesis Based on Systems Biology Technologies

Cervical cancer is one of the common malignancies in women worldwide. Exploration of pathogenesis and molecular mechanism of cervical cancer is pivotal for development of effective treatment for this disease. Recently, systems biology approaches based on high-throughput technologies have been carried out to investigate the expression of some genes and proteins in genomics, transcriptomics, proteomics, and metabonomics of cervical cancer. Compared with traditional methods，systems biology technology has been shown to provide large of information regarding prognostic biomarkers and therapeutic targets for cervical cancer. These molecular signatures from system biology technology could be useful to understand the molecular mechanisms of cervical cancer development and progression, and help physicians to design targeted therapeutic strategies for patients with cervical cancer.