Survivin gene-expression and splicing isoforms in oral squamous cell carcinoma

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.

State of the Art in the Diagnosis and Assessment of Oral Malignant and Potentially Malignant Disorders: Present Insights and Future Outlook-An Overview

Oral Potentially Malignant Disorder (OPMD) is a significant concern for clinicians due to the risk of malignant transformation. Oral Squamous Cell Carcinoma (OSCC) is a common type of cancer with a low survival rate, causing over 200,000 new cases globally each year. Despite advancements in diagnosis and treatment, the five-year survival rate for OSCC patients remains under 50%. Early diagnosis can greatly improve the chances of survival. Therefore, understanding the development and transformation of OSCC and developing new diagnostic methods is crucial. The field of oral medicine has been advanced by technological and molecular innovations, leading to the integration of new medical technologies into dental practice. This study aims to outline the potential role of non-invasive imaging techniques and molecular signatures for the early detection of Oral Malignant and Potentially Malignant Disorders.

Alternative Splicing Landscape of Head and Neck Squamous Cell Carcinoma

Head and neck malignancies are a significant global health concern, with head and neck squamous cell carcinoma (HNSCC) being the sixth most common cancer worldwide accounting for > 90% of cases. In recent years, there has been growing recognition of the potential role of alternative splicing (AS) in the etiology of cancer. Increasing evidence suggests that AS is associated with various aspects of cancer progression, including tumor occurrence, invasion, metastasis, and drug resistance. Additionally, AS is involved in shaping the tumor microenvironment, which plays a crucial role in tumor development and response to therapy. AS can influence the expression of factors involved in angiogenesis, immune response, and extracellular matrix remodeling, all of which contribute to the formation of a supportive microenvironment for tumor growth. Exploring the mechanism of AS events in HNSCC could provide insights into the development and progression of this cancer, as well as its interaction with the tumor microenvironment. Understanding how AS contributes to the molecular changes in HNSCC cells and influences the tumor microenvironment could lead to the identification of new therapeutic targets. Targeted chemotherapy and immunotherapy strategies tailored to the specific AS patterns in HNSCC could potentially improve treatment outcomes and reduce side effects. This review explores the concept, types, processes, and technological advancements of AS, focusing on its role in the initiation, progression, treatment, and prognosis of HNSCC.

The analysis of Survivin promoter (-31G/C) gene variation in oral squamous cell carcinoma risk and prognosis

BACKGROUND/AIM

Oral squamous cell carcinoma (OSCC) is a malign tumor that associated with smoking and alcohol consumption, eating habits, environmental factors, and genetic susceptibility of the individuals. The Survivin gene, also known as BIRC5, plays important roles in the regulation of the cell cycle and apoptosis. The aim of the present study is to investigate Survivin -31G/C polymorphism in OSCC development and prognosis.

MATERIALS AND METHODS

A total of 61 patients with oral squamous cell carcinoma and 133 healthy individuals were genotyped by using the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism method (PCR-RFLP) to evaluate the role of the Survivin gene promoter region (-31) variation.

RESULTS

There were no statistically significant differences in the distribution of Survivin promoter -31 polymorphism genotype and allele frequencies between the cases and controls but we analyzed the clinicopathological characteristics of patients and noticed a significant correlation between the C allele and advanced tumor stage in the patients (p = 0.022).

CONCLUSION

The Survivin (-31) gene polymorphism might be associated with advanced tumor stage in oral squamous cell carcinoma but further studies in a larger population are needed most effective evaluation of the Survivin (-31) gene variation in the OSCC risk and prognosis.

Survivin: A Potential Marker of Resistance to Somatostatin Receptor Ligands

CONTEXT

Invasive and somatostatin receptor ligand (SRL)-resistant pituitary tumors represent a challenge in the clinical practice of endocrinologists. Efforts have been made to elucidate reliable makers for both. Survivin and eukaryotic translation initiation factor-binding protein 1 (4EBP1) are upregulated in several cancers and involved in apoptosis and cell proliferation.

OBJECTIVE

We explored the role of these markers in somatotropinomas.

METHODS

Immunostains for survivin and 4EBP1, and also for somatostatin receptor type 2 (SSTR2), Ki-67, and cytokeratin 18, were analyzed in tissue microarrays containing 52 somatotropinoma samples. Tumor invasiveness was evaluated in all samples while drug resistance was evaluated in 34 patients who received SRL treatment. All these parameters were correlated with first-generation SRL (fg-SRL) responsiveness and tumor invasiveness.

RESULTS

Low survivin expression (P = 0.04), hyperintense signal on T2 weighted image (T2WI) (P = 0.01), younger age (P = 0.01), sparsely granular adenomas (SGA) (P = 0.04), high postoperative growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels (P = 0.049 and P < 0.001, respectively), and large postoperative tumor size (P = 0.02) were associated with resistance to fg-SRL. Low survivin and SSTR2 expression and high 4EBP1 expression were associated with SGA (P = 0.04, P = 0.01, and P = 0.001, respectively). Younger age (P = 0.03), large tumor pre- and postoperative (P = 0.04 and P = 0.006, respectively), low SSTR2 expression (P = 0.03), and high baseline GH and IGF-1 (P = 0.01 and P = 0.02, respectively) were associated with tumor invasiveness. However, survivin, 4EBP1, Ki-67, and granulation patterns were not associated with tumor invasion.

CONCLUSION

This study suggests that low survivin expression is predictive of resistance to fg-SRL in somatotropinomas, but not of tumor invasiveness.

Emerging roles of alternative RNA splicing in oral squamous cell carcinoma

Alternative RNA splicing (ARS) is an essential and tightly regulated cellular process of post-transcriptional regulation of pre-mRNA. It produces multiple isoforms and may encode proteins with different or even opposite functions. The dysregulated ARS of pre-mRNA contributes to the development of many cancer types, including oral squamous cell carcinoma (OSCC), and may serve as a biomarker for the diagnosis and prognosis of OSCC and an attractive therapeutic target. ARS is mainly regulated by splicing factors, whose expression is also often dysregulated in OSCC and involved in tumorigenesis. This review focuses on the expression and roles of splicing factors in OSCC, the alternative RNA splicing events associated with OSCC, and recent advances in therapeutic approaches that target ARS.

Serum Survivin in Oral Submucosal Fibrosis and Squamous Cell Carcinoma

Survivin, an inhibitor of apoptosis protein is a biomarker of significance in prognostication of many malignancies. In the current study we investigated the serum survivin levels in patients with oral submucosal fibrosis (OSMF) and squamous cell carcinoma (OSCC). Serum was isolated from, peripheral blood collected of clinically and histopathologically confirmed OSMF and OSCC patients. Circulating level of survivin was measured in patients and control subjects by ELISA and analyzed further using Kruskal-Wallis test and two-sample Wilcoxon rank-sum (Mann-Whitney) test. Serum Survivin levels were significantly reduced in the OSCC group as compared to the control group. No significant correlation was noted between the serum survivin level and various clinicopathological characteristics of OSCC and OSMF patients. Our study suggests that free, wild form of circulating survivin probably has no role in predicting the prognosis of oral cancer or the malignant transformation potential of oral submucosal fibrosis.

The prognostic significance of survivin expression in patients with HNSCC: a systematic review and meta-analysis

Background

Survivin has been recently identified as a promising novel therapeutic target and prognostic marker in different types of cancer. Here we conducted a comprehensive meta-analysis to better clarify they the precise prognostic and diagnostic value of survivin in head and neck squamous cell carcinoma (HNSCC).

Methods

Database of PubMed (Medline), Embase, and Web of Science were systematically searched for related published literature up to September 2020. Pooled hazards ratios (HR) and related 95% confidence intervals (CI) were used to estimate the association of survivin expression and survival outcomes in HNSCC patients.

Results

Twenty eight studies with 4891 patients were finally included in this meta-analysis, the pooled analysis indicated that the survivin expression was significantly correlated with poorer overall survival (OS) (HR, 2.02; 95% CI, 1.65–2.47, P < 0.001), and poorer disease-free survival (DFS)/ disease-specific survival (DSS) (HR = 2.03, 95%CI: 1.64–2.52, P < 0.001; HR = 1.92, 95%CI: 1.41–2.60, P < 0.001, receptively). Similar results were observed in subgroup analysis stratified by different cancer types, such as laryngeal squamous cell carcinoma (LSCC) (HR = 1.35, 95%CI: 1.05–1.74, P < 0.001), oral squamous cell carcinomas (OSCC) (HR = 2.45, 95%CI: 1.89–3.17, P < 0.001), nasopharyngeal carcinoma (NPC) (HR = 2.53, 95%CI: 1.76–3.62, P < 0.001) and HNSCC (HR = 1.52, 95%CI: 1.25–1.86, P < 0.001). Furthermore, ethnicity-stratified analysis indicated that survivin was significantly associated with poorer OS among both Asian and Non- Asian HNSCC patients (HR = 2.16, 95%CI: 1.76–2.66; HR = 1.56, 95%CI: 1.33–1.82, respectively).

Conclusions

Our results suggested that survivin is predictors of worse prognosis in HNSCC patients. Hence, survivin is a potential therapeutic target for HNSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08170-3.

Sex Hormones and Inflammation Role in Oral Cancer Progression: A Molecular and Biological Point of View

Oral cancers have been proven to arise from precursors lesions and to be related to risk behaviour such as alcohol consumption and smoke. However, the present paper focuses on the role of chronic inflammation, related to chronical oral infections and/or altered immune responses occurring during dysimmune and autoimmune diseases, in the oral cancerogenesis. Particularly, oral candidiasis and periodontal diseases introduce a vicious circle of nonhealing and perpetuation of the inflammatory processes, thus leading toward cancer occurrence via local and systemic inflammatory modulators and via genetic and epigenetic factors.

Expression of Survivin and Its Splice Variants in Pediatric Acute Lymphoblastic Leukemia

Aims: Survivin is involved in the inhibition of apoptosis and the regulation of cell division. In addition to wild-type survivin (survivin-wt), at least four splice variants with differential functions (ΔEx3 and 3B antiapoptotic, and 2α and 2B proapoptotic) have been identified. Survivin is highly expressed in several cancers, including hematological malignancies. Although acute lymphoblastic leukemia (ALL) is the most frequent malignancy in children, studies that investigated survivin expression in ALL are limited, and there is no study on 3B and 2α expression in ALL. Therefore the expression of survivin-wt and its splice variants was investigated in pediatric B-cell ALL patients. Materials and Methods: The expression of survivin-wt and its four splice variants was investigated by quantitative real-time polymerase chain reaction in archival RNA samples of 35 pediatric B-cell ALL patients. Patients were divided into high- and standard-risk groups according to age, white blood cell count, extramedullary involvement, and genetic risk factors; expression of survivin variants was compared between these two risk groups. Results: We found that the ratio of survivin-ΔEx3/wild type (WT) expression was higher in the low-risk group than in the high-risk group. Conclusion: Comparative analysis between the high- and low-risk B-cell ALL groups indicated that the survivin-ΔEx3/WT expression ratio could potentially be used in risk classification for pediatric B-cell ALL.

Overexpression of nicotinamide N-methyltransferase in HSC-2 OSCC cell line: effect on apoptosis and cell proliferation

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is the most common malignancy of oral cavity. Despite advances in therapeutic approaches, the 5-year survival rate for oral cancer has not improved in the last three decades. Therefore, new molecular targets for early diagnosis and treatment of OSCC are needed. In the present study, we focused on the enzyme nicotinamide N-methyltransferase (NNMT). We have previously shown that enzyme expression is upregulated in OSCC and NNMT knockdown in PE/CA PJ-15 cells significantly decreased cell growth in vitro and tumorigenicity in vivo.

MATERIAL AND METHODS

To further explore the role of the enzyme in oral cancer cell metabolism, HSC-2 cells were transfected with the NNMT expression vector (pcDNA3-NNMT) and the effect of enzyme upregulation on cell proliferation was evaluated by MTT assay. Subsequently, we investigated at molecular level the role of NNMT on apoptosis and cell proliferation, by exploring the expression of β-catenin, survivin, and Ki-67 by real-time PCR. Moreover, we performed immunohistochemistry on 20 OSCC tissue samples to explore the expression level of NNMT and survivin ΔEx3 isoform.

RESULTS

Enzyme upregulation significantly increased cell growth in vitro. Moreover, a positive correlation between NNMT and survivin ΔEx3 isoform expression levels was found both in HSC-2 cells and in OSCC tissue samples.

CONCLUSION

Taken together, our results indicate a possible involvement of NNMT in the proliferation and tumorigenic capacity of OSCC cells and seem to suggest that the enzyme could represent a potential target for the treatment of oral cancer.

CLINICAL RELEVANCE

The involvement of NNMT in cell growth and anti-apoptotic mechanisms seems to suggest that this enzyme could be a new therapeutic target to improve the survival of OSCC patients.

Apoptosis-sensitizing activity of birinapant in head and neck squamous cell carcinoma cell lines

Inhibitor of apoptosis proteins, which are overexpressed in head and neck squamous cell carcinoma (HNSCC), may cause therapeutic resistance. Using SMAC mimetic compounds, including birinapant, to degrade and/or inhibit these proteins and sensitize apoptosis may enhance therapies in HNSCC. Fas expression was analyzed in nine HNSCC cell lines and one keratinocyte cell line via flow cytometry. These cell lines were treated with Fas ligand-Fc (FasL) and birinapant, a bivalent SMAC mimetic, in mono and combination therapies. Cytotoxicity was measured using a crystal violet assay. Annexin V assay was performed for detection of apoptosis. The treatment efficacy of mono and combination therapies was statistically analyzed. Nonlinear regression analysis was performed to determine the inhibitory concentration (IC₁₀) of birinapant. Fas expression was detected in each cell line tested. Mono treatment with FasL revealed minor to no apoptotic effects in the majority of the cell lines. Crystal violet and Annexin V staining revealed increased apoptosis rates for all cell lines following incubation with birinapant in mono treatment. Combination treatment with FasL and birinapant (IC₁₀) revealed additional and synergistic effects in eight out of the ten cell lines. To the best of our knowledge, the present study provided the first evidence of the apoptosis-sensitizing activity of combination treatment with FasL and birinapant in HNSCC cell lines.

Smoking cessation leads to changes in survivin expression in oral mucosa

BACKGROUND

Survivin is an inhibitor protein of apoptosis and plays a role in oral carcinogenesis mechanism.

METHODS

The aim of this study was to evaluate the effect of smoking in survivin expression of oral mucosa of chronic smokers with and without oral squamous cell carcinoma (OSCC). The study was composed of three groups: Group 1-26 patients smoking more than 20 cigarettes/day/10 years without either history of oral malignant neoplasia or visible clinical signs in the examined site; Group 2-26 patients with OSCC; Group 3-22 patients surgically treated for OSCC for at least 1 month. The immunohistochemistry was performed with 1 smear for each group and analyzed by microscopy regarding extension, intensity of positive cells for survivin, and intracellular location.

RESULTS

The survivin expression was observed in 100% of the cases in Group 1, 88.5% in Group 2, and 100% in Group 3. Concerning to Groups 1 and 3, the survivin expression with cytoplasmic location occurred in 100%, while in Group 2 occurred in 87.5%. The cytoplasmic and nuclear expression was observed only in Group 2, with 7.69%. The results were correlated with clinical-pathological data by Fischer's exact test with significant relation between smoking cessation and intensity (P = .015) for Group 2.

CONCLUSIONS

The extension and intensity of survivin expression in the cytological smears were related to the smoking cessation in the group with OSCC. However, the smoking history (packs/years) did not influence the survivin expression.

Nuclear survivin promoted by acetylation is associated with the aggressive phenotype of oral squamous cell carcinoma

Defects in apoptotic pathway contribute to development and progression of oral cancer. Survivin, a member of the inhibitors of apoptosis protein (IAP) family, is increased in many types of cancers. However, it is unclear whether increased survivin is associated with oral squamous cell carcinomas (OSCC), and what mechanisms may involve in. In this study, we examined survivin expression in OSCC compared with normal oral tissues via immunohistochemical staining. The results showed that, not only total survivin is increased in OSCCs, but also the subcellular location of survivin is changed in OSCCs compared with normal oral tissues. In most of normal oral tissues, survivin staining was either negative, or cytoplasmic positive/nuclear negative; whereas in most of OSCC tissues, survivin staining was nuclear positive. Statistic analysis indicates that nuclear survivin, rather than total or cytoplasmic one, correlates with tumor TNM stage and differentiation grade. Consistently, in vitro analysis showed that survivin is in cytoplasm in normal human oral kinotinocyte (HOK) cells; whereas it is in nucleus in OSCC HN6 cells. Importantly, treatment of HOK cells with HDAC inhibitor Trichostatin A (TSA) induces survivin acetylation and promotes its nuclear localization. Moreover, nuclear survivin in OSCC cells was acetylated at K129 in its C-terminal, suggesting that the acetylation is important for nuclear location of survivin. Our study demonstrates that it is nuclear survivin, rather than total or cytoplasmic one, associates with TNM stage and tumor grade of OSCC. Thus, we propose nuclear survivin as a prognostic marker for the progression of OSCC.

Survivin, a molecular target for therapeutic interventions in squamous cell carcinoma

Squamous cell carcinoma (SCC) is the most common cancer worldwide. The treatment of locally advanced disease generally requires various combinations of radiotherapy, surgery, and systemic therapy. Despite aggressive multimodal treatment, most of the patients relapse. Identification of molecules that sustain cancer cell growth and survival has made molecular targeting a feasible therapeutic strategy. Survivin is a member of the Inhibitor of Apoptosis Protein (IAP) family, which is overexpressed in most of the malignancies including SCC and totally absent in most of the normal tissues. This feature makes survivin an ideal target for cancer therapy. It orchestrates several important mechanisms to support cancer cell survival including inhibition of apoptosis and regulation of cell division. Overexpression of survivin in tumors is also associated with poor prognosis, aggressive tumor behavior, resistance to therapy, and high tumor recurrence. Various strategies have been developed to target survivin expression in cancer cells, and their effects on apoptosis induction and tumor growth attenuation have been demonstrated. In this review, we discuss recent advances in therapeutic potential of survivin in cancer treatment.

Does Notch play a tumor suppressor role across diverse squamous cell carcinomas?

The role of Notch pathway in tumorigenesis is highly variable. It can be tumor suppressive or pro‐oncogenic, typically depending on the cellular context. Squamous cell carcinoma (SCC) is a cancer of the squamous cell, which can occur in diverse human tissues. SCCs are one of the most frequent human malignancies for which the pathologic mechanisms remain elusive. Recent genomic analysis of diverse SCCs identified marked levels of mutations in NOTCH1, implicating Notch signaling pathways in the pathogenesis of SCCs. In this review, evidences highlighting NOTCH's role in different types of SCCs are summarized. Moreover, based on accumulating structural information of the NOTCH receptor, the functional consequences of NOTCH1 gene mutations identified from diverse SCCs are analyzed, emphasizing loss of function of Notch in these cancers. Finally, we discuss the convergent view on an intriguing possibility that Notch may function as tumor suppressor in SCCs across different tissues. These mechanistic insights into Notch signaling pathways will help to guide the research of SCCs and development of therapeutic strategies for these cancers.

High expression of survivin and its splice variants survivin ΔEx3 and survivin 2 B in oral cancers

OBJECTIVES

We have previously reported inactivation of p53 in 46% of Indian patients with oral cancer. Survivin, a p53 target gene and an inhibitor of apoptosis protein (IAP), is overexpressed in several cancers, including oral cancers. Studies assessing the role of survivin and its splice variants in oral cancers are, however, rare.

MATERIALS AND METHODS

The expression of 6 survivin isoforms in 4 oral cancer cell lines (AW8507, AW13516, UPCI-SCC040, UPCI-SCC029 B), a dysplastic oral cell line (DOK), 75 paired oral tumor and adjacent normal tissues, and 12 normal oral tissue samples from healthy individuals was analyzed by real-time PCR. The expression was correlated with clinicopathologic parameters, which included age, sex, tumor-node-metastasis (TNM) staging, tobacco and/or alcohol consumption, site, and differentiation status of tumor.

RESULTS

This is the first study to find overexpression of the 6 characterized survivin isoforms in oral cancers compared with normal tissues (P < .05). Additionally, a significant (P < .05) correlation among the fold changes of all 6 survivin isoforms was observed. Survivin wild type (wt) was the predominantly expressed isoform in oral cell lines and tumor tissues versus normal tissues (P < .05). Among the minor isoforms, survivin ΔEx3 and survivin 2 B were dominantly expressed, whereas survivin 2 α and survivin 3 α overexpression was found for the first time. Further high survivin 3 B expression exhibited a significant association (P < .05) with poorly differentiated tumors. Interestingly the combined expression of the antiapoptotic survivin isoforms, survivin wt, survivin ΔEx3, and survivin 3 B, exhibited a significant association with TNM staging of the tumor.

CONCLUSIONS

Our studies thus indicate that oral cancers overexpress the antiapoptotic survivin variants, which exhibit an association with advanced tumor stage, implying a role for these variants in oral tumorigenesis.

Clinicopathological and prognostic significance of survivin expression in patients with oral squamous cell carcinoma: evidence from a meta-analysis

BACKGROUND

Survivin has been proposed as a promising prognostic marker in oral squamous cell carcinoma (OSCC), but the published data on survivin expression in patients with this condition are controversial. To address this we performed a meta-analysis systematically to assess the clinicopathological and prognostic significance of survivin expression in OSCC.

METHODS

We searched PubMed, Embase, Web of Science and Ovid databases for papers investigating the clinicopathological and prognostic significance of survivin expression in OSCC. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to determine the relevance of survivin.

RESULTS

A total of 15 papers, including 1040 cases in which survivin expression was detected by immunohistochemistry (IHC) or reverse transcription polymerase chain reaction (RT-PCR), were included. A meta-analysis of clinicopathological variables revealed a correlation between survivin expression and lymph node metastasis (OR = 0.62, 95% CI = 0.44-0.88, p < 0.05) and clinical stage (OR = 0.63, 95% CI = 0.41-0.96, p < 0.05). However, no significant associations were found between survivin expression and tumor differentiation grade (OR = 0.72, 95%CI = 0.26-1.11, p > 0.05), depth of invasion (OR = 0.76, 95% CI = 0.50-1.14, p > 0.05), age (OR = 0.78, 95% CI = 0.48-1.29, p > 0.05) or gender (OR = 1.31, 95% CI = 0.86-2.01, p > 0.05). Subgroup analysis using stratified detection methods showed no significant associations between the expression of survivin protein and clinicopathological variables in OSCC. A correlation between survivin expression and poor prognosis of patients with OSCC (HR = 1.62, 95% CI = 1.23-2.01, p < 0.05) was demonstrated.

CONCLUSION

Survivin is a potential prognostic marker of OSCC. Future studies with larger sample sizes and well-designed inclusion criteria will be needed to dissect the role of survivin expression in determining the clinicopathological features and/or prognosis of OSCC.

Survivin transcript variant 2 drives angiogenesis and malignant progression in proneural gliomas

BACKGROUND

The influence of survivin isoforms on outcome in glioblastoma is poorly understood. We analyzed the dominant anti-apoptotic transcript variants of survivin using expression data and modeled them in vivo to determine their impact on glioma formation and progression.

METHODS

Using data from low- and high-grade glioma knowledge bases, we expressed the anti-apoptotic isoforms of survivin (transcript variants 1 and 2) in vivo using the RCAS/Ntv-a model of murine glioma.

RESULTS

In low-grade gliomas, survivin RNA expression was increased in 22 of 167 (13.2%) of cases and was associated with shortened survival (P = .005). Survivin RNA was preferentially expressed in proneural (PN) relative to mesenchymal high-grade gliomas (P < .0001). In proneural gliomas, survivin was expressed in 94 of 141 (67%) of cases and was associated with shorter disease-free survival (P = .04). In a platelet-derived growth factor subunit B-dependent murine model of PN glioma, ectopic expression of variant 1 yielded tumors in 28 of 30 (93%) of mice, of which 25% were high-grade tumors, whereas ectopic expression of variant 2 yielded tumors in 27 of 28 (96%), of which 81% were high-grade tumors (P < .0001). Microvascular proliferation was significantly more prominent (P < .0001), and tumor-free survival was shorter in mice with variant 2 than variant 1-derived tumors (P = .01).

CONCLUSIONS

Survivin expression in low-grade gliomas is associated with poor survival and is preferentially expressed in PN gliomas. Compared with variant 1, variant 2 was associated with poorer survival and promoted malignant progression, angiogenesis, and shorter tumor-free survival in the PN murine model. Inhibiting survivin transcript variant 2, rather than variant 1 (the common isoform), may be an effective treatment strategy for glioma.

The role of survivin in thyroid tumors: differences of expression in well-differentiated, non-well-differentiated, and anaplastic thyroid cancers

BACKGROUND

Survivin is involved in human cancer and is responsible for aggressive biological behavior and poor clinical outcomes in several human malignancies. Thus, we hypothesized that the upregulation of survivin protein expression may be enhanced in parallel with transition toward a poorly differentiated phenotype in human thyroid carcinomas.

METHODS

The expression of survivin was evaluated, using a standard linked streptavidin-biotin horseradish peroxidase technique technique, in a series of 56 human thyroid carcinomas (42 papillary, 4 poorly differentiated, and 10 anaplastic carcinomas) and thyroid carcinoma cell lines at different degrees of differentiation.

RESULTS

The cytoplasmic expression of survivin protein was significantly upregulated in all thyroid tumors. A statistically significant association was found between nuclear survivin expression and anaplastic thyroid cancer (mean ± SD: well-differentiated thyroid cancer, 1.22 ± 20.21; non-well-differentiated thyroid cancer, 34.00 ± 25.17; anaplastic thyroid cancer, 56.50 ± 22.10; p<0.001). Nuclear staining of survivin has been shown in poorly differentiated and anaplastic thyroid carcinomas, and this is likely due to the upregulation of the ΔEx3 survivin splicing variant, as shown in poorly differentiated/anaplastic thyroid carcinoma cell lines. Of note, selected thyroid tumors characterized by a mixed population of differentiated and undifferentiated neoplastic cells, likely progressing from well to poorly differentiated and anaplastic phenotypes, exhibited cytoplasmic expression of survivin in differentiated fields and nuclear protein staining in poorly differentiated and anaplastic areas. This expression profile provides substantial added value to conventional clinical markers in predicting anaplastic cancer. The cut-off for distinguishing thyroids that developed ATC from those that remained differentiated was >30% of nuclear survivin expression. The receiver operating characteristic (ROC) area was 0.92, with a p-value of <0.0001.

CONCLUSIONS

Upregulation of survivin expression may be a molecular marker of dedifferentiation in thyroid epithelial carcinomas, likely being responsible for survival responses of tumor cells and, thus, favoring progression toward a poorly differentiated phenotype.

BRAF mutation and RASSF1A expression in thyroid carcinoma of southern Italy

Aim of this work is to provide a detailed comparison of clinical-pathologic features between well-differentiated and poorly differentiated tumors according to their BRAF and RASSF1A status. We analyzed RASSF1A methylation by MSP and BRAF mutation by LCRT-PCR with LightMix® kit BRAF V600E in neoplastic thyroid tissues. Immunohistochemical evaluation of RASSF1A expression was also performed by standard automated LSAB-HRP technique. An overall higher degree of RASSF1A over-expression than normal thyroid parenchyma surrounding tumors (P < 0.05) has been found in all malignant well-differentiated lesions. Moreover, statistically significant higher levels of RASSF1A expression were observed in differentiated cancers associated to an inflammatory autoimmune background (P = 0.01). Amplifiable DNA for LC PCR with LightMix® kit BRAF V600E was obtained in nine PTCs, four FVPTCs, five ATCs, and one control. The V600E mutation was found in 13 of 18 (72%) tumors. BRAF was mutated in 6 of 9 (66%) classical PTC, in 2 of 4 (50%) follicular variant PTC and in all ACs (100%). The overall frequency of RASSF1A promoter methylation observed was 20.5% (9 cases out 44). Hypermethylation of RASSF1A in primary tumors was variable according to histotypes ranging from100% (5/5) in ACs to only 12.5% (4/32) in PTCs. We show a correlation between RASSF1A methylation status and RASSF1A protein expression. Finally, we conclude that BRAF V600E mutation and RASSF1A methylation were pathogenetic event restricted to a subgroup of PTC/FVPTCs in early stage and to clinically aggressive ATCs.

Clinico-pathologic relevance of Survivin splice variant expression in cancer

Survivin is a member of the inhibitor of apoptosis (IAP) family and has multifunctional properties that include aspects of proliferation, invasion and cell survival control. Survivin is a promising candidate for targeted cancer therapy as its expression is associated with poor clinical outcome, more aggressive clinico-pathologic features, and resistance to radiation and chemotherapy. In the present review the different properties of the Survivin splice variants are discussed and their activities correlated with different aspects of cancer cell biology, to include subcellular location. Special emphasis is placed on our current understanding of these Survivin splice variants influence on each other and on the phenotypic responses to therapy that they may control.

Immunoprofiling of oral squamous cell carcinomas reveals high p63 and survivin expression

BACKGROUND

Cancer is a multifactorial disease composed of cells that show somatic mutations and epigenetic changes. The aim of this study was to investigate the expression of proteins involved in the development and maintenance of epithelia, cell cycle regulation, and apoptosis in human oral squamous cell carcinoma (OSCC) tissue samples.

METHODS

A tissue microarray containing 65 primary human OSCC specimens was immunolabeled for bcl-2, survivin, epidermal growth factor receptor (EGFR), p21, p53, p63, and cleaved caspase-3.

RESULTS

Samples were scored for percentage of positively stained tumor cells and staining intensity. A total immunostaining score was also calculated, using the product of percentage and intensity scores. All specimens showed high scores, > 75%, for p63 and survivin, and 75.4% of the specimens also presented high EGFR expression. All cases showed p53-positive cells. p21 showed a diffuse staining pattern. The percentage of cells positive for cleaved caspase-3 and bcl-2 was low.

CONCLUSIONS

The high frequency of tumor cells expressing p63 and survivin highlights the role of these proteins in the malignant transformation of oral epithelium. Collectively, our results suggest that p63 and survivin may constitute attractive targets for cancer therapy in patients with OSCC.

Aberrant beta-catenin and LEF1 expression may predict the clinical outcome for patients with oropharyngeal cancer

Beta-catenin, normally expressed on the epithelial cell surface, plays a crucial role in cadherin-mediated cell adhesion. Recent evidence suggests that beta-catenin is also involved in other functions such as intracellular signaling via the Wnt pathway by creating a nuclear complex with members of the Lymphoid-Enhancer-Factor/T-Cell-Factor (LEF/TCF) family of transcription factors, and gene regulation that it is implicated in the development of several tumors. Little information is available on beta-catenin expression and its main partner in the Wnt signaling pathway, LEF1, in oropharyngeal squamous cell carcinomas (OP-SCCs). The aim of this study is to investigate the expression of beta-catenin and LEF1 expression in human primary OP-SCCs and to evaluate their clinical and prognostic significance. OP-SCCs and normal peritumoral areas were analyzed by immunohistochemistry, Western-blot and RT-PCR. Beta-catenin was overexpressed in tumors in comparison to normal peritumoral areas and displayed predominantly intracellular (cytosolic/nuclear) localization in 62&#x0025; of the tumors. Immunoreactivity was correlated with clinicopathological parameters and long-term follow-up, and a significant association was found between protein expression and development of local recurrences (P =0.03). The OP-SCCs with poor clinical outcome, which displayed intracellular beta-catenin expression, were also strongly positive for LEF1, with their co-expression statistically significant (P = 0.040). All (100&#x0025;) advanced (stages 3+4) SCCs, 66.7&#x0025; of the SCCs with positive lymph nodes and 80&#x0025; of the SSCs that developed local recurrences were LEF1 positive. Cox regression analysis confirmed a poorer overall survival in cases with high expression of beta-catenin and LEF1. Our results suggest that assessing intracellular beta-catenin and LEF1 expression might help in patient risk stratification and outcome prediction, and serve as novel therapeutic targets in advanced OP-SCC.

Survivin splice variants are not essential for mitotic progression or inhibition of apoptosis induced by doxorubicin and radiation

Survivin is a critical regulator of mitosis, and an inhibitor of apoptosis which is overexpressed in almost all cancers. In the current study, cell cycle profiles of normal proliferating human umbilical vein endothelial cells, prostate cancer, and lung cancer cell lines expressing varying levels of survivin and its splice variants were compared using a novel functional complementation assay. Defects in chromosome segregation and cytokinesis that were observed after depletion of endogenous survivin were not complemented by any of the survivin splice variants: survivin-2B, survivin-3B, survivin-ΔEx3, or survivin-2A when expressed exogenously at a level comparable to endogenous full-length survivin. Survivin variants were not detectable at the endogenous protein level. Cancer cells with higher levels of full-length survivin and survivin-2B expression, exhibited reduced caspase-3 activation following doxorubicin treatment and radiation. Whereas earlier studies focused on function and expression levels of survivin specific to cancer cells, the current study brings forward the essential role of survivin in normal dividing cells. Full-length survivin was found to be associated with Aurora-B kinase in the chromosomal passenger complex and depletion of survivin mimics mitotic phenotypes observed after Aurora-B kinase inhibition, in cancer as well as normal proliferating cells. Thus, our study establishes survivin as a marker of proliferation, rather than a cancer specific marker. Therefore, systemic therapeutic interventions targeting survivin will affect cancer as well as normal proliferating cells.

Survivin promoter -31G/C polymorphism in oral cancer cell lines

Survivin (SVV) is a protein that belongs to the inhibitor of apoptosis proteins (IAP) family and is involved in the G2/M phase progression of the cell cycle as a spindle‑associated molecule. The biological features of this protein are well documented and its activity appears to be involved in mitochondria-dependent and -independent antiapoptotic pathways. Overexpression of SVV at the transcriptional and translational level has been associated with cancer, a multifactorial disorder in which the occurrence of a -31G to C polymorphism in the promoter region may significantly contribute to the development of this pathology. To verify this hypothesis, the occurrence of a single nucleotide polymorphism (SNP) in cis-acting cell cycle-dependent elements (CDEs) and in cell cycle homology regions (CHRs) of the survivin TATA-less promoter was investigated. A total of 23 oral squamous cell carcinoma (OSCC) cell lines and normal epithelium-derived normal human epidermal keratinocyte (NHEK) cell lines were analyzed by RFLP and direct DNA sequencing of their promoter region. Furthermore, survivin expression at the transcriptional and translational levels was evaluated in these cells by RT-PCR and Western blotting, respectively. The findings indicate that the presence of a G or C allele is not directly correlated to survivin expression, at the mRNA or at the protein level, at least in the OSCC lines analyzed in this study.

Aurora B expression as a prognostic indicator and possible therapeutic target in oral squamous cell carcinoma

The aim of this study is to investigate the expression of the chromosomal passenger protein Aurora B and its activated (phosphorylated) form in a large series of human oral squamous cell cancers (OSCC) and to evaluate its clinical and prognostic significance. Western blotting analysis revealed overexpression of both Aurora B and Thr-232 Phopsho-Aurora B in OSCC lines as compared to normal keratinocytes and bladder cancer cells. Furthermore, protein expression was analysed by immunohistochemistry in 101 OSCC of different site, stage and histological grade and in normal peritumoural areas. The intracellular localization of Aurora B in tumour cells was mainly nuclear, especially in proliferative areas, and significant overexpression was found in tumours in comparison to normal peritumoural areas (P=0.012). Staining results were correlated with clinicopathological parameters and long-term follow-up, and a significant association was found between protein expression and tumour stage (stage II, III and IV vs stage I, P=0.030) and size (<2cm vs >2cm, P=0.010). Cox regression analysis confirmed a poorer disease-free survival in cases with high expression of Aurora B protein. Kaplan-Meier curves showed shorter time to progression in patients with high levels of Aurora B expression (p<0.05). Moreover, the tumoral group with nuclear Aurora B immunolocalization had the worst prognosis (P=0.0364 in disease free survival). Our results suggest that assessing Aurora B expression might help in patients’ risk stratification and serve as a novel therapeutic target in advanced OSCCs.

The survivin -31 snp in human colorectal cancer correlates with survivin splice variant expression and improved overall survival

BACKGROUND

Survivin is involved in the regulation of cell division and survival, two key processes in cancer. The majority of studies on survivin in colorectal cancer (CRC) have focused on protein expression and less is known about the expression of survivin splicing variants or survivin gene polymorphisms in CRC. In the present study, the mRNA levels of the five known isoforms of survivin as well as survivin protein were assessed in matched normal and neoplastic colorectal tissue. Moreover, the 9386 C/T and -31 G/C polymorphisms were investigated.

METHODS

Quantitative RT-PCR was used to assess mRNA levels in fresh/frozen tissue samples. Protein levels were immunohistochemically evaluated on formalin-fixed paraffin-embedded tissue sections. Individuals were genotyped using real time PCR.

RESULTS

Expression of all 5 survivin splice variants as well as survivin protein was elevated in colorectal carcinomas compared to normal tissue. Specific splice variant expression differentially correlated with clinicopathological parameters. Furthermore, both snps correlated with splice variant levels or their ratios in colorectal carcinomas while the -31 G/C snp may be related to CRC development and improved overall survival.

CONCLUSION

Our results support a role of survivin in colorectal carcinogenesis while the -31 G/C snp may constitute a marker of survival.

Odontogenic epithelium: immunolabeling of Ki-67, EGFR and survivin in pericoronal follicles, dentigerous cysts and keratocystic odontogenic tumors

The aim of this study was to evaluate the biological profile of odontogenic epithelium by immunolabeling of epidermal growth factor receptor (EGFR), Ki-67 and survivin in keratocystic odontogenic tumors (KOT), dentigerous cysts (DC), and pericoronal follicles (PF). Immunohistochemical analysis was performed in 13 KOTs, 14 DCs and 9 PFs. Immunolabeling was analyzed in the basal and suprabasal layers of KOTs and DCs, and in the islands of odontogenic epithelium and/or reduced enamel epithelium of PFs. KOTs showed the highest proliferation rate among the three groups, mainly in suprabasal layers. EGFR immunolabeling was observed mainly in the cytoplasm in basal and suprabasal layers of KOTs and in the suprabasal layer of DCs. Immunolabeling in both membrane and cytoplasm was greater in PFs. In PFs, membrane-only staining was observed. Survivin immunolabeling showed a greater percentage of positive cells (scoring +++) in the suprabasal layer of KOTs. In DCs, both layers showed similar percentages of cells scoring +++; PFs showed the highest percentage of these cells. In KOTs, epithelial cells showed stimulus-independent neoplastic proliferative characteristics, suggesting the presence of a suprabasal proliferative compartment, maintained by inhibition of apoptosis. In DCs, the basal layer seemed to proliferate in response to stimulus. Although PFs showed low proliferative activity, the expression of EGFR indicates that some cells have a high capacity to respond to stimuli, which could probably explain the origin of odontogenic lesions.

Expression of inhibitor of apoptosis family proteins in human oral squamous cell carcinogenesis

BACKGROUND

The purpose of this study was to determine inhibitor of apoptosis (IAP) expression, its relationship with p53, and epigenetic change in oral carcinogenesis that remain to be elucidated.

METHODS

We measured IAP and p53 expression in 44 oral potentially malignant disorders and their corresponding malignant-transformed oral squamous cell carcinomas (OSCCs), and in 44 other non-transformed oral potentially malignant disorders. IAP and p53 expression in 10 fresh OSCCs, together with epigenetic change of their mutation, were also determined.

RESULTS

Normal mucosa did not express IAP/mutated p53. Oral potentially malignant disorders that underwent transformation exhibited high IAPs (>90%) and less-consistent mutated-p53 (34%) expression, whereas transformed OSCCs exhibited high IAP and mutated-p53 expression. Fresh OSCCs exhibited 80% to 100% IAP mRNA expression and 50% protein, mRNA, and p53 mutation expression. Normal tissues revealed DNA methylation of IAP, whereas cancerous tissues overexpressing IAP exhibited hypomethylation.

CONCLUSION

This study showed that IAP expression is an early event in oral carcinogenesis and that epigenetic and genetic pathways are associated with IAP expression in OSCC.

Survivin multifaceted activity in head and neck carcinoma: current evidence and future therapeutic challenges

CONCLUSIONS

Survivin expression should be studied as a potential hallmark of higher risk oral, oropharyngeal and laryngeal squamous cell carcinomas (SCCs) to develop loco-regional recurrences. These outcomes could have a significant impact on both the treatment modalities and the intensity of post-treatment follow-up. Further investigation is necessary before considering elective neck dissection in patients with laryngeal SCC with high survivin expression.

OBJECTIVES

Functioning simultaneously at cell division and apoptosis inhibition, survivin, a member of the inhibitor of apoptosis proteins family, plays a pivotal role in determining cell survival. Significant over-expression of survivin has been demonstrated in most human malignancies and correlated with more aggressive forms. This review focuses on the attempts to translate survivin biologic properties toward both a diagnostic/prognostic tool and a novel therapeutic target in head and neck SCC (HNSCC).

MATERIALS AND METHODS

An exhaustive review of literature was performed to investigate available evidence about survivin expression, biological role and therapeutic potential in HNSCC.

RESULTS

Multiple evidence indicates that, in HNSCC cell lines, survivin inhibition by gene therapy and by small molecule inhibitors significantly increases the anti-tumour activity of several cytotoxic and other targeted therapies.