Insulin­like growth factor axis: A potential nanotherapy target for resistant cervical cancer tumors (Review).

Cervical cancer is among the most frequently occurring neoplasms worldwide, and it particularly affects individuals in developing countries. Factors such as the low quality of screening tests, the high incidence of locally advanced cancer stages and the intrinsic resistance of certain tumors are the main causes of failure in the treatment of this neoplasm. Due to advances in the understanding of carcinogenic mechanisms and bioengineering research, advanced biological nanomaterials have been manufactured. The insulin-like growth factor (IGF) system comprises multiple growth factor receptors, including IGF receptor 1. These receptors are activated by binding to their respective growth factor ligands, IGF-1 and IGF-2, and insulin, and play an important role in the development, maintenance, progression, survival and treatment resistance of cervical cancer. In the present review, the role of the IGF system in cervical cancer and three nanotechnological applications that use elements of this system are described, namely Trap decoys, magnetic iron oxide nanoparticles and protein nanotubes. Their use in the treatment of resistant cervical cancer tumors is also discussed.

Genes Involved in the Transcriptional Regulation of Pluripotency Are Expressed in Malignant Tumors of the Uterine Cervix and Can Induce Tumorigenic Capacity in a Nontumorigenic Cell Line.

Transcription factors OCT4, SOX2, KLF4, C-MYC, and NANOG (OSKM-N) regulate pluripotency and stemness, and their ectopic expression reprograms human and murine fibroblasts that constitute the key of regenerative medicine. To determine their contribution to cell transformation, we analyzed the gene expression profiles of these transcription factors in cervical cancer samples and found that they are preferentially expressed in the tumor component. Also, cancer stem cell-enriched cultures grown as sphere cultures showed overexpression of OSKM-N genes. Importantly, we observed that lentiviral-mediated transduction of these factors confers, to a nontumorigenic immortalized human cell line, properties of cancer stem cells as the ability to form tumors in a mouse model. When we performed a meta-analysis using microarray data from cervical cancer biopsies and normal tissues, we found that the expression of OSKM-N and some target genes allowed separating tumor and normal tissues between samples, which enhanced the importance of OSKM-N in the tumorigenesis. Finally, we analyzed and compared both transcript and protein expression profiles of these factors within a cohort of patients with cervical cancer. To our knowledge, this is the first time that the expression of OSKM-N is described to induce one of the main characteristics of the cancer stem cell, the tumorigenicity. And, more importantly, its exogenous expression in a nontumorigenic cell line is sufficient to induce a tumorigenic phenotype; furthermore, the differential expression of this transcription factor distinguishes tumor tissue and normal tissue in cervical samples.

Correction to: Intratype variants of the E2 protein from human papillomavirus type 18 induce different gene expression profiles associated with apoptosis and cell proliferation.

The Given names of the author Alma Mariana Fuentes-González was incorrectly tagged in original publication and corrected here. The original article has been corrected.

Sodium-coupled monocarboxylate transporter is a target of epigenetic repression in cervical cancer.

The SLC5A8 gene encodes Na monocarboxylate transporter 1, which is epigenetically inactivated in various tumour types. This has been attributed to the fact that it prevents the entry of histone deacetylase (HDAC) inhibitors and favours the metabolic reprogramming of neoplastic cells. Nevertheless, its expression and regulation in cervical cancer (CC) have not been elucidated to date. The aim of the present study was to investigate whether SLC5A8 expression is silenced in CC and if epigenetic mechanisms are involved in its regulation. Using RNA and DNA from human CC cell lines and tumour tissues from patients with CC, the expression of SLC5A8 was analysed by reverse transcription polymerase chain reaction and the methylation status of its CpG island (CGI) by bisulphite­modified sequencing. Additionally, SLC5A8 reactivation was examined in the CC cell lines following treatment with DNA methylation (5­aza­2'­deoxycytidine) and HDAC inhibitors (trichostatin A and pyruvate). All the CC cell lines and a range of tumour tissues (65.5%) exhibited complete or partial loss of SLC5A8 transcription. The bisulphite­sequencing revealed that hypermethylation of the CGI within SLC5A8 first exon was associated with its downregulation in the majority of cases. The transporter expression was restored in the CC cell lines following exposure to 5­aza­2'­deoxycytidine alone, or in combination with trichostatin A or pyruvate, suggesting that DNA methylation and histone deacetylation contribute to its inhibition in a cell line­dependent manner. Together, the results of the present study demonstrate the key role of DNA hypermethylation in the repression of SLC5A8 in CC, as well as the involvement of histone deacetylation, at least partially. This allows for research focused on the potential function of SLC5A8 as a tumour suppressor in CC, and as a biomarker or therapeutic target in this malignancy.

Intratype variants of the E2 protein from human papillomavirus type 18 induce different gene expression profiles associated with apoptosis and cell proliferation.

Persistent infections with high-risk human papillomaviruses (HR-HPVs) are linked to the development of cervical cancer due to a deregulation of the productive viral cycle in the host cell, leading to cell transformation. The E2 viral protein is expressed early during an HPV infection and regulates viral replication and transcription. Other functions have been attributed to E2, such as the promotion of apoptosis that are independent of its role in the regulation of the expression of E6 and E7 viral oncogenes. Moreover, it has been shown that the HPV16 E2 protein has regulatory effects on cellular gene expression, suggesting that it participates in the modulation of different cellular processes. Intratype genomic variations within high-risk HPV types have an impact on the prognosis of HPV-related lesions. Nevertheless, the biological significance of HPV18 E2 intratype variations has not been analysed previously. The aim of this study was to determine whether HPV18 E2 intratype variations differentially modulate gene expression and whether cell-death-related genes are affected by variations in E2. We demonstrate that HPV18 E2 intratype Asian Amerindian (AsAi) and African (Af) variants differentially affect gene expression profiles. Although the E2-AsAi variant was found to modulate a larger number of cellular genes, both E2 variants affected similar cellular processes. Nevertheless, E2-AsAi and E2-Af variants showed differences in their ability to induce apoptosis, where E2-Af had a stronger effect. The differences in gene expression profiles in cells harbouring E2 intratype variants suggest a possible effect on diverse cellular signalling pathways, and this might suggest an approach for identifying biological processes regulated by HPV18 E2 intratype variants.

Gene signature based on degradome-related genes can predict distal metastasis in cervical cancer patients.

Cervical cancer is one of the leading causes of death in women worldwide, which mainly affects developing countries. The patients who suffer a recurrence and/or progression disease have a higher risk of developing distal metastases. Proteases comprising the degradome given its ability to promote cell growth, migration, and invasion of tissues play an important role during tumor development and progression. In this study, we used high-density microarrays and quantitative reverse transcriptase polymerase chain reaction to evaluate the degradome profile and their inhibitors in 112 samples of patients diagnosed with locally advanced cervical cancer. Clinical follow-up was done during a period of 3 years. Using a correlation analysis between the response to treatment and the development of metastasis, we established a molecular signature comprising eight degradome-related genes (FAM111B, FAM111A, CFB, PSMB8, PSMB9, CASP7, PRSS16, and CD74) with the ability to discriminate patients at risk of distal metastases. In conclusion, present results show that molecular signature obtained from degradome genes can predict the possibility of metastasis in patients with locally advanced cervical cancer.

Comprehensive transcriptome analysis identifies pathways with therapeutic potential in locally advanced cervical cancer.

OBJECTIVE: The objective of the present study was to provide genomic and transcriptomic information that may improve clinical outcomes for locally advanced cervical cancer (LACC) patients by searching for therapeutic targets or potential biomarkers through the analysis of significantly altered signaling pathways in LACC. METHODS: Microarray-based transcriptome profiling of 89 tumor samples from women with LACC was performed. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, significantly over-expressed genes in LACC were identified; these genes were validated by quantitative reverse transcription-polymerase chain reaction in an independent cohort, and the protein expression data were obtained from the Human Protein Atlas. RESULTS: A transcriptome analysis revealed 7530 significantly over-expressed genes in LACC samples. By KEGG analysis, we found 93 dysregulated signaling pathways, including the JAK-STAT, NOTCH and mTOR-autophagy pathways, which were significantly upregulated. We confirmed the overexpression of the relevant genes of each pathway, such as NOTCH1, JAK2, STAM1, SOS1, ADAM17, PSEN1, NCSTN, RPS6, STK11/LKB1 and MLTS8/GBL in LACC compared with normal cervical tissue epithelia. CONCLUSIONS: Through comprehensive genomic and transcriptomic analyses, this work provides information regarding signaling pathways with promising therapeutic targets, suggesting novel target therapies to be considered in future clinical trials for LACC patients.

Transcriptomic Profiling of Adipose Tissue in Obese Women in Response to Acupuncture Catgut Embedding Therapy with Moxibustion.

OBJECTIVE: Complementary and alternative medicine, such as Traditional Chinese Medicine, represents an efficient therapeutic option for obesity control. It was previously reported that acupuncture catgut embedding therapy (ACET) with moxibustion reduces body weight and reverts insulin resistance in obese women. This study aimed to evidence changes in adipokines and gene expression in adipose tissue that could explain the effects of ACET with moxibustion. DESIGN: Overweight/obese women were treated with ACET with moxibustion or sham acupuncture as control. Peripheral blood samples and fat biopsies were taken before and after intervention. Circulating adipokines (leptin, adiponectin, tumor necrosis factor alpha, and resistin) were quantified by enzyme-linked immunosorbent assay. Gene expression in adipose tissue was determined by cDNA microarray assays and assessed by quantitative reverse transcription real-time polymerase chain reaction. RESULTS: ACET with moxibustion did not modify circulating adipokines levels. However, correlations with anthropometric and biochemical parameters were affected. Interestingly, transcriptional changes in adipose tissue revealed the modulation of genes participating in homeostasis control, lipid metabolism, olfactory transduction, and gamma-aminobutyric acid signaling pathway. CONCLUSIONS: The effects of ACET with moxibustion on body weight and insulin resistance were associated with the regulation of biochemical events that are altered in obesity.

A microRNA expression signature for clinical response in locally advanced cervical cancer.

OBJECTIVE: Nearly 50% of patients who are diagnosed with locally advanced cervical cancer have an unfavorable pathological response to conventional treatment. MicroRNAs (miRNAs) are potential biomarkers in cervical cancer; however, their role in identifying patients who do not respond to conventional treatment remains poorly investigated. Here, we identify a set of miRNAs that can be used as molecular markers to predict the pathological response in locally advanced cervical cancer patients receiving radiation and chemotherapy treatment. METHODS: Forty-one patients diagnosed with locally advanced cervical cancer were invited to participate in this study and enrolled after they signed an informed consent. Two patient cohorts were randomized for miRNA expression profiling, a discovery cohort (n=10) and a validation cohort (n=31); profiling was performed by means of a miScript miRNA PCR Array. After a median clinical follow-up of 45months, statistical analysis was performed to identify miRNAs that could discriminate non-responders from complete pathological responders to conventional treatment. RESULTS: miRNA expression profiling identified 101 miRNAs that showed significant differences between non-responders and complete pathological responders (p<0.05). Seven differentially expressed miRNAs were selected, and their expression patterns were confirmed in the validation phase; thus, miR-31-3p, -3676, -125a-5p, -100-5p, -125b-5p, and -200a-5p and miR-342 were significantly associated with clinical response. Expression of this miRNA signature above the median level was a significant predictor of non-response to standard treatment (p<0.001). CONCLUSIONS: These seven validated miRNA signatures could be used as molecular biomarkers of chemo- and radio-resistance in locally advanced cervical cancer patients.

PAX8 is transcribed aberrantly in cervical tumors and derived cell lines due to complex gene rearrangements.

The transcription factor PAX8, a member of the paired box-containing gene family with an important role in embryogenesis of the kidney, thyroid gland and nervous system, has been described as a biomarker in tumors of the thyroid, parathyroid, kidney and thymus. The PAX8 gene gives rise to four isoforms, through alternative mRNA splicing, but the splicing pattern in tumors is not yet established. Cervical cancer has a positive expression of PAX8; however, there is no available data determining which PAX8 isoform or isoforms are present in cervical cancer tissues as well as in cervical carcinoma-derived cell lines. Instead of a differential pattern of splicing isoforms, we found numerous previously unreported PAX8 aberrant transcripts ranging from 378 to 542 bases and present in both cervical carcinoma-derived cell lines and tumor samples. This is the first report of PAX8 aberrant transcript production in cervical cancer. Reported PAX8 isoforms possess differential transactivation properties; therefore, besides being a helpful marker for detection of cancer, PAX8 isoforms can plausibly exert differential regulation properties during carcinogenesis.

Transcript profiling distinguishes complete treatment responders with locally advanced cervical cancer.

Cervical cancer (CC) mortality is a major public health concern since it is the second cause of cancer-related deaths among women. Patients diagnosed with locally advanced CC (LACC) have an important rate of recurrence and treatment failure. Conventional treatment for LACC is based on chemotherapy and radiotherapy; however, up to 40% of patients will not respond to conventional treatment; hence, we searched for a prognostic gene signature able to discriminate patients who do not respond to the conventional treatment employed to treat LACC. Tumor biopsies were profiled with genome-wide high-density expression microarrays. Class prediction was performed in tumor tissues and the resultant gene signature was validated by quantitative reverse transcription-polymerase chain reaction. A 27-predictive gene profile was identified through its association with pathologic response. The 27-gene profile was validated in an independent set of patients and was able to distinguish between patients diagnosed as no response versus complete response. Gene expression analysis revealed two distinct groups of tumors diagnosed as LACC. Our findings could provide a strategy to select patients who would benefit from neoadjuvant radiochemotherapy-based treatment.

MicroRNAs in cervical cancer: evidences for a miRNA profile deregulated by HPV and its impact on radio-resistance.

Cervical carcinoma (CC) is one of the most common cancers and a leading cause of mortality in women worldwide. Epidemiologic and experimental data have clearly demonstrated a causal role of high-risk Human Papillomavirus (HR-HPV) types in CC initiation and progression, affecting the cellular processes by targeting and inactivating p53 and pRB host proteins. HR-HPV E5, E6 and E7 oncoproteins have the ability to deregulate several cellular processes, mostly apoptosis, cell cycle control, migration, immune evasion, and induction of genetic instability, which promote the accumulation of mutations and aneuploidy. In this scenario, genomic profiles have shown that aberrant expression of cellular oncogenic and tumor suppressive miRNAs have an important role in CC carcinogenesis. It has been stated that HPV infection and E6/E7 expression are essential but not sufficient to lead to CC development; hence other genetic and epigenetic factors have to be involved in this complex disease. Recent evidence suggests an important level of interaction among E6/E7 viral proteins and cellular miRNA, and other noncoding RNAs. The aim of the current review is to analyze recent data that mainly describe the interaction between HR-HPV established infections and specific cellular miRNAs; moreover, to understand how those interactions could affect radio-therapeutic response in tumor cells.

microRNA-18b is upregulated in breast cancer and modulates genes involved in cell migration.

microRNAs are small non-coding RNAs of ~22 nucleotides that function at post-transcriptional level as negative regulators of gene expression. Aberrant expression of microRNAs could promote uncontrolled proliferation, migration and invasion of human cancer cells. In this study, we analyzed the expression of microRNA-18b (miR-18b) in breast cancer cell lines and in a set of clinical specimens. Our results showed that miR-18b was upregulated in four out of five breast cancer cell lines and also in breast tumors. In order to identify potential gene targets, we carried out transcriptional profiling of MDA-MB-231 breast cancer cells that ectopically expressed miR-18b. Our results showed that 263 genes were significantly modulated in miR-18b-deficient cells (fold change >1.5; P≤0.05). We found that knock-down of miR-18b induced the upregulation of 55 olfactory receptor (OR) genes and nine genes (NLRP7, KLK3, OLFM3, POSTN, MAGED4B, KIR3DL3, CRX, SEMG1 and CEACAM5) with key roles in cell migration and metastasis. Consistently, we found that ectopic inhibition of miR-18b suppressed the migration of two breast cancer cell models in vitro. In conclusion, we have uncovered genes directly or indirectly modulated by miR-18b which may represent potential therapeutic targets in breast cancer. Our data also pointed out a role of miR-18b in migration of breast cancer cells.

The 25 kDa subunit of cleavage factor Im Is a RNA-binding protein that interacts with the poly(A) polymerase in Entamoeba histolytica.

In eukaryotes, polyadenylation of pre-mRNA 3' end is essential for mRNA export, stability and translation. Taking advantage of the knowledge of genomic sequences of Entamoeba histolytica, the protozoan responsible for human amoebiasis, we previously reported the putative polyadenylation machinery of this parasite. Here, we focused on the predicted protein that has the molecular features of the 25 kDa subunit of the Cleavage Factor Im (CFIm25) from other organisms, including the Nudix (nucleoside diphosphate linked to another moiety X) domain, as well as the RNA binding domain and the PAP/PAB interacting region. The recombinant EhCFIm25 protein (rEhCFIm25) was expressed in bacteria and used to generate specific antibodies in rabbit. Subcellular localization assays showed the presence of the endogenous protein in nuclear and cytoplasmic fractions. In RNA electrophoretic mobility shift assays, rEhCFIm25 was able to form specific RNA-protein complexes with the EhPgp5 mRNA 3´ UTR used as probe. In addition, Pull-Down and LC/ESI-MS/MS tandem mass spectrometry assays evidenced that the putative EhCFIm25 was able to interact with the poly(A) polymerase (EhPAP) that is responsible for the synthesis of the poly(A) tail in other eukaryotic cells. By Far-Western experiments, we confirmed the interaction between the putative EhCFIm25 and EhPAP in E. histolytica. Taken altogether, our results showed that the putative EhCFIm25 is a conserved RNA binding protein that interacts with the poly(A) polymerase, another member of the pre-mRNA 3' end processing machinery in this protozoan parasite.