Regulation of Survivin Isoform Expression by GLI Proteins in Ovarian Cancer

Survivin (BIRC5): Implications in cancer therapy

Inhibitors of Apoptosis proteins (IAPs) were discovered through experiments aimed at rescuing apoptosis in insects. Classically associated with the inhibition of apoptosis, the IAP member Survivin also regulates cell cycle progression and is an essential component of the Chromosomal Passenger Complex (CPC), responsible for chromosomal segregation. Although undetectable in most adult tissues, Survivin is expressed in Adult Stem Cells (ASCs) and plays a crucial role in their maintenance. Survivin is overexpressed in most cancers, contributing to their clonal expansion. As a result, it has been proposed as a possible anticancer target for nearly two decades. In this discussion, we will explore the rationale behind Survivin as a therapeutic target, focusing on common cancer types such as carcinomas, sarcomas, and leukemias. We will delve into the modulation of Survivin by cancer pro-survival cell signaling, the association between SNPs and tumorigenesis, and its regulation by miRNAs. Finally, we will compare cell growth, clonogenic capacity, and apoptosis, along with different strategies for Survivin inhibition, including gene expression and protein activity modulation.

BIRC5 Gene Polymorphisms Are Associated with a Higher Stage of Local and Regional Disease in Oral and Oropharyngeal Squamous Cell Carcinomas

Oral squamous cell carcinoma (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC) are the most common types of cancers in the head and neck region (HNSCC). Despite very aggressive treatment modalities, the five-year survival rate has not changed for decades and is still around 60%. The search for potential specific biomarkers of aggressiveness or outcome indicators could be of great benefit in improving the treatment of these patients. One of the potential biomarkers is survivin, the protein product of the BIRC5 gene. In this study, we investigated the occurrence of BIRC5 gene polymorphisms in 48 patients with OSCC and OPSCC compared with healthy controls. A total of 18 polymorphisms were found, 11 of which occurred in HNSCC with a minor allele frequency (MAF) of more than 5%. Five polymorphisms (rs3764383, rs9904341, rs2071214, rs2239680, rs2661694) were significantly associated with tumor size, tumor stage, and advanced regional disease, but had no impact on survival.

Nucleic acid vaccination strategies for ovarian cancer

High grade serous carcinoma (HGSC) is one of the most lethal ovarian cancers that is characterised by asymptomatic tumour growth, insufficient knowledge of malignant cell origin and sub-optimal detection. HGSC has been recently shown to originate in the fallopian tube and not in the ovaries. Conventional treatments such as chemotherapy and surgery depend upon the stage of the disease and have resulted in higher rates of relapse. Hence, there is a need for alternative treatments. Differential antigen expression levels have been utilised for early detection of the cancer and could be employed in vaccination strategies using nucleic acids. In this review the different vaccination strategies in Ovarian cancer are discussed and reviewed. Nucleic acid vaccination strategies have been proven to produce a higher CD8+ CTL response alongside CD4+ T-cell response when compared to other vaccination strategies and thus provide a good arena for antitumour immune therapy. DNA and mRNA need to be delivered into the intracellular matrix. To overcome ineffective naked delivery of the nucleic acid cargo, a suitable delivery system is required. This review also considers the suitability of cell penetrating peptides as a tool for nucleic acid vaccine delivery in ovarian cancer.

Survivin in Breast Cancer: A Review

Breast cancer is the most frequently diagnosed cancer in women and ranks second among causes for cancer-related death in women. Gene technology has led to the recognition that breast cancer is a heterogeneous disease composed of different biological subtypes, and genetic profiling enables the response to chemotherapy to be predicted. This fact emphasizes the importance of selecting sensitive diagnostic and prognostic markers in the early disease stage and more efficient targeted treatments for this disease. One such prognostic marker appears to be survivin. Many studies have shown that survivin is strongly expressed in different types of cancers. Its overexpression has been demonstrated in breast cancer, and high activity of the survivin gene has been associated with a poor prognosis and worse survival rates.

Survivin, Sonic hedgehog, Krüppel-like factors, and p53 pathway in serous ovarian cancer: an immunohistochemical study

OBJECTIVE

Survivin was previously associated with tumor stage and grade in ovarian cancer and interfered with the tumor's drug sensitivity. In addition, Survivin expression was found to be regulated by the Sonic hedgehog (Shh) pathway, Krüppel-like factor (KLF) family proteins, and p53 pathway. The main aim of this study was to assess the prognostic values of immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a cohort of high grade ovarian serous cancers. Other aims were comparison between high- and low-grade ovarian serous cancer and between platinum-resistant and the other cases. The last aim was to assess the correlations among the immunohistochemical expression of the studied proteins.

METHODS

Retrospective cohort study to assess immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a tissue microarray of primary tumor samples among 73 women affected by high-grade ovarian serous cancer and 9 by low-grade ovarian serous cancer.

RESULTS

Klf5 and Shh cytoplasmic staining were associated to short overall survival (HR 6.38, CI.95 2.25 - 18.01, p<0.05 and 2.25, CI.95 1.19-4.23, p<0.05 respectively). In addition, cytoplasmic Klf5 staining, high Klf11 and p53 nuclear staining were associated with platinum resistance (p<0.05). Cytoplasmic Shh score was significantly correlated to the immunohistochemical expression of Klf5, Klf11, Mdm2, and Survivin.

CONCLUSIONS

Our data highlight the possible role of Klf5 and Shh as prognostic markers, meanwhile confirming the role of the KLF family proteins and p53 in ovarian cancer drug resistance. Moreover, Shh appeared to play an important role in the intracellular network of ovarian neoplasia.

Advances in glioma-associated oncogene (GLI) inhibitors for cancer therapy

The Hedgehog/Glioma-associated oncogene homolog (HH/GLI) signaling pathway regulates self-renewal of rare and highly malignant cancer stem cells, which have been shown to account for the initiation and maintenance of tumor growth as well as for drug resistance, metastatic spread and relapse. As an important component of the Hh signaling pathway, glioma-associated oncogene (GLI) acts as a key signal transmission hub for various signaling pathways in many tumors. Here, we review direct and indirect inhibitors of GLI; summarize the abundant active structurally diverse natural GLI inhibitors; and discuss how to better develop and utilize GLI inhibitors to solve the problem of drug resistance in tumors of interest. In summary, GLI inhibitors will be promising candidates for various cancer treatments.

Sonic Hedgehog signaling pathway in gynecological and genitourinary cancer (Review)

Cancers of the urinary tract, as well as those of the female and male reproductive systems, account for a large percentage of malignancies worldwide. Mortality is frequently affected by late diagnosis or therapeutic difficulties. The Sonic Hedgehog (SHH) pathway is an evolutionary conserved molecular cascade, which is mainly associated with the development of the central nervous system in fetal life. The present review aimed to provide an in‑depth summary of the SHH signaling pathway, including the characterization of its major components, the mechanism of its upstream regulation and non‑canonical activation, as well as its interactions with other cellular pathways. In addition, the three possible mechanisms of the cellular SHH cascade in cancer tissue are discussed. The aim of the present review was to summarize significant findings with regards to the expression of the SHH pathway components in kidney, bladder, ovarian, cervical and prostate cancer. Reports associated with common deficits and de‑regulations of the SHH pathway were summarized, despite the differences in molecular and histological patterns among these malignancies. However, currently, neither are SHH pathway elements included in panels of prognostic/therapeutic molecular patterns in any of the discussed cancers, nor have the drugs targeting SMO or GLIs been approved for therapy. The findings of the present review may support future studies on the treatment of and/or molecular targets for gynecological and genitourinary cancers.

FI-Net: Identification of Cancer Driver Genes by Using Functional Impact Prediction Neural Network

Identification of driver genes, whose mutations cause the development of tumors, is crucial for the improvement of cancer research and precision medicine. To overcome the problem that the traditional frequency-based methods cannot detect lowly recurrently mutated driver genes, researchers have focused on the functional impact of gene mutations and proposed the function-based methods. However, most of the function-based methods estimate the distribution of the null model through the non-parametric method, which is sensitive to sample size. Besides, such methods could probably lead to underselection or overselection results. In this study, we proposed a method to identify driver genes by using functional impact prediction neural network (FI-net). An artificial neural network as a parametric model was constructed to estimate the functional impact scores for genes, in which multi-omics features were used as the multivariate inputs. Then the estimation of the background distribution and the identification of driver genes were conducted in each cluster obtained by the hierarchical clustering algorithm. We applied FI-net and other 22 state-of-the-art methods to 31 datasets from The Cancer Genome Atlas project. According to the comprehensive evaluation criterion, FI-net was powerful among various datasets and outperformed the other methods in terms of the overlap fraction with Cancer Gene Census and Network of Cancer Genes database, and the consensus in predictions among methods. Furthermore, the results illustrated that FI-net can identify known and potential novel driver genes.

Ovarian cancer risk according to circulating zinc and copper concentrations: A meta-analysis and Mendelian randomization study

BACKGROUND & AIMS

Ovarian cancer is a lethal disease with few modifiable risk factors. Circulating zinc and copper are potential biomarkers for ovarian cancer; however, evidence of their causal effects are scarce. This study aimed to examine the impact of circulating zinc and copper concentrations on ovarian cancer risk, using meta-analysis and Mendelian randomization (MR) approaches.

METHODS

Twenty case-control studies, including 699 patients with ovarian cancer, 567 patients with benign ovarian lesions, and 1194 healthy controls, were selected for meta-analysis. With a Two-sample MR approach, genetic instruments of 21 single nucleotide polymorphisms (SNPs) associated with circulating zinc and 25 SNPs associated with circulating copper were created. Their genetic associations with ovarian cancer were extracted from a genome-wide association study of 25,509 ovarian cancer cases and 40,941 controls.

RESULTS

Ovarian cancer patients had significantly lower concentrations of circulating zinc than healthy controls (Standardized mean differences [SMD] = -1.01, 95% CI: -1.38 to -0.64). In contrast, circulating copper concentrations were significantly higher in ovarian cancer patients (SMD = 1.46, 95% CI: 0.82 to 2.09). In MR analysis, we only found increased circulating zinc concentration causally associated with a lower risk of ovarian cancer (odds ratio = 0.968, 95% CI: 0.941 to 0.995, per SD of ranked-inverse normalized concentration), especially in the high-grade serous subtype.

CONCLUSIONS

Although increased circulating copper and decreased zinc concentrations were found in ovarian cancer patients, a suggestive causal association was only detected with zinc concentration, suggesting further studies on zinc interventions for ovarian cancer might have clinical impact.

Strategies for Delivery of siRNAs to Ovarian Cancer Cells

The unmet need for novel therapeutic options for ovarian cancer (OC) deserves further investigation. Among the different novel drugs, small interfering RNAs (siRNAs) are particularly attractive because of their specificity of action and efficacy, as documented in many experimental setups. However, the fragility of these molecules in the biological environment necessitates the use of delivery materials able to protect them and possibly target them to the cancer cells. Among the different delivery materials, those based on polymers and lipids are considered very interesting because of their biocompatibility and ability to carry/deliver siRNAs. Despite these features, polymers and lipids need to be engineered to optimize their delivery properties for OC. In this review, we concentrated on the description of the therapeutic potential of siRNAs and polymer-/lipid-based delivery systems for OC. After a brief description of OC and siRNA features, we summarized the strategies employed to minimize siRNA delivery problems, the targeting strategies to OC, and the preclinical models available. Finally, we discussed the most interesting works published in the last three years about polymer-/lipid-based materials for siRNA delivery.