Expression of the apoptosis inhibitor survivin in aggressive squamous cell carcinoma

Immunohistochemical evaluation of survivin in oral lichen planus and oral squamous cell carcinoma - a retrospective study

Introduction

Oral cancer is a multistep process involving enhanced activation of proto-oncogenes. Survivin (anti-apoptotic protein) is one of such proto-oncogenes that contribute to the carcinogenesis by deregulating cell proliferation. Expression of these proteins in cancerous and pre-cancerous lesions helps a better understanding of the etiology, treatment and prognosis.

Aim

To evaluate qualitative and quantitative expression of survivin in healthy mucosa, oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC).

Methods

A total of 70 cases of formalin fixed paraffin embedded blocks, of which 20 healthy mucosa, 20 OSCC and 30 OLP were included in the study and stained immunohistochemically using antibodies against survivin monoclonal antibody. 4 μm sections were stained immunohistochemically, both nuclear and cytoplasmic staining was considered as positive for surviving. Positive and negative stained cells were counted with the help of Olympus BX51 rarefaction microscope and were analyzed quantitatively using image analysis pro plus software. Representative fields were randomly selected at 40× high power magnification. Values obtained were evaluated and tabulated for statistical analysis.

Results

There was a statistically significant relation between the expressions of survivin among healthy mucosa, OLP, OSCC with a p value of 0.001.

Conclusion

Presence of survivin expression in healthy mucosa, OLP and OSCC, which is an inhibitor of apoptosis protein, can be identified as a useful diagnostic tool for the identification of precancerous lesions and conditions which are at higher risk for progression into invasive carcinoma.

Thymoquinone induces apoptosis of human epidermoid carcinoma A431 cells through ROS-mediated suppression of STAT3

Black seed (Nigella sativa) oil has been used in various dermatological applications, and its major constituent, thymoquinone (TQ) has been shown to exhibit antiproliferative activity against various cancer cells. In this study, we tried to provide a mechanistic basis of apoptosis induced by TQ. Skin squamous carcinoma A431 cells were treated with TQ to monitor the apoptosis induced by TQ. Western blot analysis was performed to detect expression of apoptotic or anti-apoptotic proteins. Cell viability and apoptosis were measured by using the MTT test and FACS analysis, respectively. The induction of intracellular reactive oxygen species (ROS) by TQ was evaluated by 2',7'-dichlorofluorescein diacetate staining. In vivo xenograft study was followed to confirm the antiproliferative effect of TQ. Treatment of A431 cells with TQ-induced apoptosis, which was associated with the induction of p53 and Bax, inhibition of Mdm2, Bcl-2, and Bcl-xl expression, and activation of caspase-9, -7, and -3. TQ inhibited the constitutive phosphorylation and DNA binding activity of signal transducer and activator of transcription-3 (STAT3) in A431 cells by blocking the phosphorylation of the upstream kinase, Src. Moreover, the expression of STAT3 target gene products, cyclin D1 and survivin, was attenuated by TQ treatment. The generation of ROS was increased during TQ-induced apoptosis, and the pretreatment of N-acetyl cysteine, a ROS scavenger, reversed the apoptotic effect of TQ. In vivo study with NOD scid gamma (NSG) mice confirmed the inhibitory effect of TQ on the growth of A431 cells. Our results provide the first demonstration that TQ induces the apoptosis of A431 cells through generation of ROS and inhibition of STAT3 signaling.

Yin Yang 1 (YY1): Regulation of Survivin and Its Role In Invasion and Metastasis

Despite significant clinical and basic science advancements, cancer remains a devastating disease that affects people of all ages, races, and backgrounds. The pathogenesis of cancer has recently been described to result from eight biological capabilities or hallmarks and two enabling characteristics. These eight hallmarks are: deregulation of cellular energetics, avoiding immune destruction, enabling replicative immortality, inducing angiogenesis, sustaining proliferative signaling, evading growth suppressors, resisting cell death, and activating invasion and metastasis. The enabling characteristics are: genome instability and mutation and tumor-promoting inflammation. Survivin, the fourth most common transcript found in cancer cells, is a protein that is thought to be involved in the enhanced proliferation, survival, and metastasis and possibly other key hallmarks of cancer cells. Understanding how this gene is turned on and off is vitally important for attempt improving cancer management and therapy. Our work has identified a novel transcriptional regulator of survivin called Yin Yang 1 (YY1), which has been observed to activate some gene promoters and repress others and is gaining increasing interest as a target of cancer therapy. Our work shows for the first time that YY1 represses survivin transcription by physically interacting with the survivin promoter. Furthermore, YY1 appears to contribute to basal survivin transcriptional activity, indicating that disruption of its binding may in part contribute to survivin overexpression after cellular stress events including chemotherapy and radiotherapy.

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.

Survivin-Based Treatment Strategies for Squamous Cell Carcinoma

Survivin, an anti-apoptotic molecule abundantly expressed in most human neoplasms, has been reported to contribute to cancer initiation and drug resistance in a wide variety of human tumors. Efficient downregulation of survivin can sensitize tumor cells to various therapeutic interventions, generating considerable efforts in its validation as a new target in cancer therapy. This review thoroughly analyzes up-to-date information on the potential of survivin as a therapeutic target for new anticancer treatments. The literature dealing with the therapeutic targeting of survivin will be reviewed, discussing specifically squamous cell carcinomas (SCCs), and with emphasis on the last clinical trials. This review gives insight into the recent developments undertaken in validating various treatment strategies that target survivin in SCCs and analyze the translational possibility, identifying those strategies that seem to be the closest to being incorporated into clinical practice. The most recent developments, such as dominant-negative survivin mutants, RNA interference, anti-sense oligonucleotides, small-molecule inhibitors, and peptide-based immunotherapy, seem to be helpful for effectively downregulating survivin expression and reducing tumor growth potential, increasing the apoptotic rate, and sensitizing tumor cells to chemo- and radiotherapy. However, selective and efficient targeting of survivin in clinical trials still poses a major challenge.

Current Insights into Oral Cancer Epigenetics

Epigenetic modifications have emerged into one of the cancer hallmarks, replacing the concept of malignant pathologies as being solely genetic-based conditions. The epigenetic landscape is responsible for normal development but also for the heterogeneity among tissues in terms of gene expression patterns. Dysregulation in these mechanisms has been associated with disease stage, and increased attention is now granted to cancer in order to take advantage of these modifications in terms of novel therapeutic strategies or diagnosis/prognosis tools. Oral cancer has also been subjected to epigenetic analysis with numerous studies revealing that the development and progression of this malignancy are partially induced by an altered epigenetic substrate together with genetic alterations and prolonged exposure to environmental risk factors. The present review summarizes the most important epigenetic modifications associated with oral cancer and also their potential to be used as new therapeutic targets.

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.

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.

Prognostic role of survivin in renal cell carcinoma: A system review and meta-analysis

BACKGROUND

Survivin plays an important role in cancer pathogenesis, which has been suggested to be related to poor prognosis in renal cell carcinoma (RCC). We performed a meta-analysis to quantify the prognostic value of survivin in renal cell carcinoma (RCC) patients.

PATIENTS AND METHODS

Relevant articles exploring the relationship between survivin expression and survival of RCC patients published up to 10 November 2015 were retrieved in PubMed, Web of science and Cochrane databases. The summary hazard ratio (HR) and 95% confidence interval (CI) were calculated by a random-effects model.

RESULTS

A total of 1583 patients from 10 studies were included. The high expression of survivin was associated with poor Overall Survival (OS) in two studies (Pooled HRs=2.77, 95%CI: 1.46-5.26, I(2)=0.0%, P=0.329). Further, meta-analysis of seven studies showed that elevated survivin expression predicted shorter cancer-specific survival (CSS) of RCC (HR=2.85, 95% CI: 2.25-3.61, I(2)=17.6%, P=0.295). Additionally, subgroup analysis showed that survivin over-expression was associated significantly with worse CSS regardless of different source of survivin, sample size, follow-up duration, race and detection method.

CONCLUSIONS

A higher survivin expression seems to represent an unfavorable and robust prognostic factor for clinical outcomes in RCC patients.

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.

GNRs@SiO₂-FA in combination with radiotherapy induces the apoptosis of HepG2 cells by modulating the expression of apoptosis-related proteins

The aim of the present study was to examine the apoptosis of the hepatocellular carcinoma cell line, HepG2, induced by treatment with folic acid-conjugated silica-coated gold nanorods (GNRs@SiO₂-FA) in combination with radiotherapy, and to determine the involvement of apoptosis-related proteins. An MTT colorimetric assay was used to assess the biocompatibility of GNRs@SiO₂-FA. The distribution of GNRs@SiO₂-FA into the cells was observed using transmission electron microscopy (TEM). HepG2 cells cultured in vitro were divided into the following 4 groups: i)the control group (untreated), ii) the GNRs@SiO₂-FA group, iii) the radiotherapy group (iodine 125 seeds) and iv) the combination group (treated with GNRs@SiO₂-FA and iodine 125 seeds) groups. The apoptosis of the HepG2 cells was detected by flow cytometry. The concentration range of <40 µg/ml GNRs@SiO₂-FA was found to be safe for the biological activity of the HepG2 cells. GNRs@SiO₂-FA entered the cytoplasm through endocytosis. The apoptotic rates of the HepG2 cells were higher in the GNRs@SiO₂-FA and radiotherapy groups than in the control group (P<0.05). The apoptotic rate was also significantly higher in the combination group than the GNRs@SiO₂-FA and radiotherapy groups (P<0.05). Taken together, these findings demonstrate that the combination of GNRs@SiO₂-FA and radiotherapy more effectively induces the apoptosis of HepG2 cells. These apoptotic effects are achieved by increasing the protein expression of Bax and caspase-3, and inhibiting the protein expression of Bcl-2 and Ki-67. The combination of GNRs@SiO₂-FA and radiotherapy may thus prove to be a new approach in the treatment of primary liver cancer.

Active inflammatory biomarkers in oral lichen planus

Oral lichen planus (OLP) is a chronic disease, with a central role to cell-mediated autoimmunity. Osteopontin promotes migration and recruitment of immune cells, CD44 is its receptor, and Survivin seems to be important in skin/mucosa homeostasis. The aim of this study was to investigate their expression in biopsy specimens of patients with different OLP clinical types and healthy controls.Biopsy specimens from 30 patients with OLP (15 atrophic and 15 hyperplastic) and 15 healthy controls were subjected to immune-histochemical analysis, to detect the expression of osteopontin, CD44, and Survivin in oral epithelia. The distributions of positively stained cells were evaluated with a quantitative method, while the inflammation degree was evaluated with a semi-quantitative one.Expression of osteopontin and CD44 was higher in OLP than controls, while Survivin expression was lower in OLP patients. There was a greater reduction of Survivin expression in atrophic OLP than hyperplastic OLP. A correlation between osteopontin expression and a high degree of inflammation was found. Furthermore, Survivin expression was higher in cases with low intensity of inflammation.Osteopontin, CD44, and Survivin seem to be involved in OLP pathogenesis, and further investigations are needed for clarifying their role in this oral disease.

Survivin expression correlates with nodal metastasis in T1-T2 squamous cell carcinoma of the tongue

In this study, the correlation between neck metastasis and recurrence was investigated by studying specimens of tongue squamous cell carcinoma patients immunohistochemical with survivin antibodies in the primary biopsy. A retrospective review was conducted at the Academic University Hospital. 46 patients who had squamous cell carcinoma of the tongue, who underwent various types of glossectomy and neck dissections between 1991 and 2008, were evaluated. The patient's sex, TNM staging, differentiation and recurrence rates were analyzed. There were 20 T1 patients and 26 T2 patients; 27 of the patients were N0 and 19 had metastatic lymph nodes in the neck. Survivin antibodies were applied with streptavidin-biotin method to the sections that were prepared from the primary tumor biopsy specimens of the patients. The correlation between neck metastasis and recurrence and survivins' immunohistochemical staining was analyzed with statistical methods. There were no significant differences between the patient's age, sex, tumor's T stage, tumor differentiation and survivin staining density. Survivin staining was positive in 15 (79 %) of 19 patients with neck metastasis, while it was positive in 16 (59 %) of 27 patients without neck metastasis. Eleven (79 %) of the 14 patients who had recurrence and all 6 patients who had neck recurrence only were stained by survivin. Expression of nuclear and cytoplasmic survivin can be a useful marker for predicting cervical lymph node metastasis in T1-T2 tumors in tongue SCC.

Key differences identified between actinic keratosis and cutaneous squamous cell carcinoma by transcriptome profiling

Background:

Cutaneous squamous cell carcinoma (cSCC) is one of the most common malignancies in fair-skinned populations worldwide and its incidence is increasing. Despite previous observations of multiple genetic abnormalities in cSCC, the oncogenic process remains elusive. The purpose of this study was to elucidate key molecular events associated with progression from premalignant actinic keratoses (AKs) to invasive cSCC by transcriptome profiling.

Methods:

We combined laser capture microdissection with the Affymetrix HGU133 Plus 2.0 microarrays to profile 30 cSCC and 10 AKs.

Results:

We identified a core set of 196 genes that are differentially expressed between AK and cSCC, and are enriched for processes including epidermal differentiation, cell migration, cell-cycle regulation and metabolism. Gene set enrichment analysis highlighted a key role for the mitogen activated protein kinase (MAPK) pathway in cSCC compared with AK. Furthermore, the histological subtype of the tumour was shown to influence the expression profile.

Conclusion:

These data indicate that the MAPK pathway may be pivotal to the transition from AK to cSCC, thus representing a potential target for cSCC prevention. In addition, transcriptome differences identified between cSCC subtypes have important implications for future development of targeted therapies for this malignancy.

Expression of nuclear survivin in normal skin and squamous cell carcinoma: a possible role in tumour invasion

Background:

Survivin is detected in few adult normal cells and it is highly expressed in cancer. Nuclear survivin facilitates cell cycle entry, whereas the mitochondrial pool protects cells from apoptosis. Survivin is overexpressed in keratinocyte stem cells (KSCs) and protects them from apoptosis.

Methods:

As KSCs are at the origin of squamous cell carcinoma (SCC), we evaluated survivin expression in normal and cancerous skin in vivo by immunohistochemistry and western blotting. HaCaT cells overexpressing survivin and wound-healing assay are used. Analysis of variance and Student's T-tests are used for statistical analysis.

Results:

Survivin is localised in both the cytoplasm and nucleus of normal adult and young keratinocytes. Nuclear survivin is detected in one every 10 of 11 basal keratinocytes. When present in suprabasal cells, nuclear survivin is coexpressed with K10 but not with K15 or p75-neurotrophin receptor (p75NTR), a transit amplifying cell marker. Nuclear, but not cytoplasmic, survivin expression markedly increases in actinic keratosis and in SCC in situ, as compared with normal epidermis, and it is highest in poorly differentiated SCC. In SCC tumours, nuclear survivin-positive cells are mainly K10/p75NTR-negative and K15-positive. In poorly differentiated tumours, survivin mostly localises in the deep infiltrating areas. When overexpressed in keratinocytes, survivin increases cell migration.

Conclusion:

High survivin expression and the subcellular localisation of survivin correlate with keratinocyte differentiation and are associated with undifferentiated and more invasive SCC phenotype.

Epithelial-to-mesenchymal transition: immunohistochemical investigation of related molecules in canine cutaneous epithelial tumours

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is a multistep process, important in tumour invasion and metastasis, characterized by loss of epithelial markers, redistribution of β-catenin and gain of mesenchymal markers. HYPOSTHESIS/OBJECTIVES: Our aim was to investigate the immunohistochemical aberrant expression of cytokeratin, vimentin, survivin and heat shock protein 72 (Hsp72) in canine cutaneous epithelial tumours, to understand the association of expression of these molecules with features of malignancy and their role in the EMT phenotype.

METHODS

Ten canine squamous cell carcinomas (SCCs; one with lymph node metastasis), 30 canine hair follicle tumours (six pilomatricomas, eight infundibular keratinizing acanthomas, six trichoepitheliomas and 10 trichoblastomas) and five normal skin samples were investigated by immunohistochemistry using specific anti-vimentin, -cytokeratin, -survivin and -Hsp72 antibodies. A semi-quantitative method was used to analyse the results, as follows: 0 to <5%; ≥ 5 to <10%; ≥ 10 to <25%; and ≥ 25% of positive cells. Immunofluorescence was performed to investigate survivin-vimentin and survivin-Hsp72 colocalization in selected SCCs. Results - In malignant hair follicle tumours and SCCs, a reduced intensity of cytokeratin and increased survivin and Hsp72 expression were observed. In SCCs, loss of cytokeratin expression and vimentin immunolabelling, suggestive of the EMT phenotype, were evident in <5% of neoplastic cells in the front of tumour invasion. In the same areas, strong nuclear survivin and cytoplasmic Hsp72 staining was evident, often colocalizing. Only a few neoplastic cells in the front of tumour invasion showed vimentin-survivin colocalization.

CONCLUSIONS AND CLINICAL IMPORTANCE

A possible simultaneous involvement of survivin and Hsp72 in tumour invasion and the multistep process of EMT of cutaneous epithelial tumours of dogs is suggested.

Epigenetic mechanisms in oral carcinogenesis

Dysregulation of gene expression is a frequent occurrence in oral squamous cell carcinoma (OSCC). However, accumulating evidence suggests that in contrast to genetics, epigenetic modifications consisting of aberrant DNA methylation, histone modifications and altered expression of miRNAs induce OSCC tumorigenesis and perhaps play a more central role in the evolution and progression of this disease. The unifying theme among these three epigenetic mechanisms remains the same, which is aberrant regulation of gene expression. In this article, we provide a comprehensive review of the impact of epigenetics on oral tumorigenesis with a systematic report on aberrant DNA methylation, histone modifications and miRNA regulation in the pathogenesis of OSCC. We provide insights into recent studies on the prospect of biomarkers for early detection and indication of disease recurrence, and novel treatment modalities.

Survivin: a dual player in healthy and diseased skin

Survivin belongs to the inhibitor of apoptosis (IAP) protein family, and, in addition to the antiapoptotic functions, it also regulates the cell cycle. The survivin gene generates five major isoforms with diverse and opposite functions. Survivin is highly expressed in cancer and in few normal adult tissues, including skin. It is mostly detected in the nucleus of keratinocyte stem cells (KSCs), but it is also expressed in melanocytes and fibroblasts. Survivin isoforms are differentially detected in subpopulations of human keratinocytes, exerting contrasting activities. Survivin has an important role in the regulation of cell cycle in keratinocytes, and it protects these cells from anoikis and UV-induced apoptosis. In melanoma, survivin is abundantly expressed, and its subcellular localization varies depending upon tumor thickness and invasiveness. Survivin overexpression has been shown in squamous cell carcinoma (SCC), and it is also involved in UVB-induced carcinogenesis. The presence of survivin both in the nucleus and in the cytoplasm throughout the epidermal layers of psoriatic lesions suggests the involvement of this protein in the keratinocyte alterations typical of this disease. Additional studies on the expression of survivin isoforms and their subcellular localization in relation to function will confirm the key role of survivin in the skin and will open the field to new therapeutic strategies for many cutaneous conditions.

Inhibition of human lung adenocarcinoma growth using survivint34a by low-dose systematic administration

Anti-apoptosis plays an important role in tumour formation and development. Survivin is a member of the inhibitor of apoptosis (IAP) family, which is a target for anti-cancer drug exploitation was replaced as development. We investigated the role of the homo dominant-negative mutant Survivin-T34A in suppressing human lung adenocarcinomas (A549). The anti-tumour activity of HSurvivinT34A plasmid was evaluated in the A549 cell line and nude mice bearing A549 subcutaneous tumours. Low-dose systemic administration was continuously used. The HSurvivinT34A plasmid (5 meu g/one) complexed with a cationic liposome (DOTAP/Chol) significantly inhibited tumour growth in our model. We observed microvessel density degradation by CD31 immunohistochemistry and apoptotic cell increase by TUNEL assay, PI staining and flow cytometric analysis in the treated group. The present findings suggest that the HSurvivinT34A plasmid complexed with a cationic liposome may provide an effective approach to inhibit the growth of human lung adenocarcinomas in vitro and in vivo.

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.

Keratinocyte stem cells: friends and foes

Skin and its appendages provide a protective barrier against the assaults of the environment. To perform its role, epidermis undergoes an ongoing renewal through a balance of proliferation and differentiation/apoptosis called homeostasis. Keratinocyte stem cells reside in a special microenvironment called niche in basal epidermis, adult hair follicle, and sebaceous glands. While a definite marker has yet to be detected, data raised part in humans and part in the mouse system point to a critical role of stem and its progeny transit amplifying cells in epidermal homeostasis. Stem cells are protected from apoptosis and are long resident in adult epidermis. This renders them more prone to be the origin of skin cancer. In this review, we will outline the main features of adult stem cells in mouse and humans and discuss their fate in relation to differentiation, apoptosis, and cancer.

Down-regulation of survivin by oxaliplatin diminishes radioresistance of head and neck squamous carcinoma cells

BACKGROUND

Oxaliplatin is integrated in treatment strategies against a variety of cancers including radiation protocols. Herein, as a new strategy we tested feasibility and rationale of oxaliplatin in combination with radiation to control proliferation of head and neck squamous cell carcinoma (HNSCC) cells and discussed survivin-related signaling and apoptosis induction.

METHODS

Cytotoxicity and apoptosis induced by radiation and/or oxaliplatin were examined in relation to survivin status using two HNSCC cell lines viz., Cal27 and NT8e, and one normal 293-cell line. Survivin gene knockdown by siRNA was also tested in relevance to oxaliplatin-mediated radiosensitization effects.

RESULTS

Survivin plays a critical role in mediating radiation-resistance in part through suppression of apoptosis via a caspase-dependent mechanism. Oxaliplatin treatment significantly decreased expression of survivin in cancer cells within 24-72 h. Apoptotic cells and caspase-3 activity were increased parallely with decrease in cell viability, if irradiated during this sensitive period. The cytotoxicity of oxaliplatin and radiation combination was greater than additive. Survivin gene knockdown experiments have demonstrated the role of survivin in radiosensitization of cancer cells mediated by oxaliplatin.

CONCLUSIONS

Higher expression of survivin is a critical factor for radioresistance in HNSCC cell lines. Pre-treatment of cancer cells with oxaliplatin significantly increased the radiosensitivity through induction of apoptosis by potently inhibiting survivin.

Survivin expression in canine epidermis and in canine and human cutaneous squamous cell carcinomas

Survivin, a member of the inhibitor of apoptosis protein (IAP) family, is ubiquitously expressed during tissue development, undetectable in most normal tissues, but re-expressed in most cancers, including skin malignancies. Expression of survivin was evaluated retrospectively in 19 canine cutaneous squamous cell carcinomas (SCCs; one in situ; 16 well differentiated; one invasive, one lymph node metastasis) and 19 well differentiated SCCs from human beings. Seven specimens of normal canine skin were included. Immunohistochemical expression of full-length survivin was determined using a commercially available antibody. In addition, apoptotic rate [Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labelling index (TUNEL) index] and mitotic index (MI), counting mitoses in 10 high power fields (HPF), were determined. Scattered survivin positive nuclei were identified in the epidermal basal cell layer of normal canine skin. Nuclear survivin expression was identified in 18 of 19 human and in all canine SCCs, mainly along the base of the tumour cell population. Cytoplasmic survivin expression was rarely observed in human SCCs and in 84.2% of canine SCCs. The TUNEL index ranged from 0.1 to 2.6 in human beings and from 7.5 to 69.4 in dogs, while MIs ranged from 0 to 4 in human beings and dogs. No correlation was found between survivin expression and apoptotic or mitotic rates. Canine and human tumours showed similar nuclear survivin expression, indicating similar functions of the molecule. We demonstrated survivin expression in normal adult canine epidermis. Increased nuclear survivin expression in pre-neoplastic and neoplastic lesions demonstrates a possible association of survivin with development of SCCs in human beings and dogs.

UV-induced squamous cell carcinoma--a role for antiapoptotic signalling pathways

The incidence of nonmelanoma skin cancer including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) has dramatically increased in the last decades, and chronic sun exposure was identified as a main etiologic agent. UV radiation may produce DNA damage either directly or through reactive oxygen species (ROS). As mutations caused by UV may lead to skin cancer due to oncogene activation and tumor suppressor gene inactivation, efficient safeguard mechanisms have been developed during evolution. These enclose induction of apoptosis and formation sunburn cells aiming at the removal of premalignant cells. The keratinocyte apoptotic machinery in response to UV consists of both intrinsic/mitochondrial and extrinsic/death receptor-mediated cell-death pathways, which are particularly regulated by mitogen-activated protein kinases (MAPKs, JNK and p38) and the tumor-suppressor protein p53. For development of skin cancer, it appears that critical steps in apoptosis control are dysregulated leading to resistance both to death ligand-mediated and intrinsic proapoptotic pathways. These particularly include inactivation of p53, as well as activation of EGFR, COX-2 and MAPKs, which result in specific regulation of Bcl-2 proteins, death ligands and death receptors. The final unravelling of apoptosis regulation in epithelial skin cancer may allow the development of new targeted therapeutic strategies.

Detection of autoantibodies against survivin in sera from cancer dogs

Survivin overexpression has been reported in relation to tumor malignancy, suggesting that it is an unfavorable prognostic marker, and antibody responses to this protein have been confirmed in human cancer patients. In this study, we investigated antibody responses to survivin in canine cancer cases, and examined the prevalence of such responses by enzyme-linked immunosorbent assay (ELISA) using recombinant canine survivin protein as the antigen. The cut-off value for positivity in the anti-survivin ELISA was 0.35, as determined using the mean absorbance +2 S.D. of samples from healthy dogs. Sera from 16 of 59 (27.1%) cancer and 3 of 25 (12%) non-cancer disease dogs were positive on ELISA. The highest positivity rates (>50%) among the cancer cases were seen in dogs with mammary tumor, squamous cell carcinoma and melanoma.

Detection of survivin mRNA in healthy oral mucosa, oral leucoplakia and oral cancer

BACKGROUND

Survivin is involved in modulation of cell death and cell division processes. Survivin expression in normal adult tissues has not been fully understood, although it is markedly lower than in cancer, where it is over-expressed.

OBJECTIVE

To investigate survivin expression in normal, potentially malignant and cancerous oral mucosa.

METHODS

We measured survivin mRNA levels by real-time RT-PCR in specimens of oral mucosa (15 from normal mucosa, 17 from potentially malignant lesions, 17 from neoplasms). Scores were compared using Kruskal-Wallis test and post hoc according to Conover. Chi-squared test was used for dichotomous data.

RESULTS

The median relative levels of survivin mRNA resulted six for normal mucosa, eight for potentially malignant lesions, 13 for cancers: differences among these three groups were statistically significant, as between cancer and potentially malignant lesions. Expression in normal mucosa and potentially lesions group showed no significant difference. Low, but not marginal expression of survivin in normal mucosa is a new finding, and it could be explained with the higher sensibility of our methods.

CONCLUSIONS

Survivin expression in oral potentially malignant lesions might indicate a progressive deregulation of expression paralleling oncogenesis, particularly during the first stages of process, suggesting a putative predictive role for survivin.

Expression of P27, Ki67 and P53 in squamous cell carcinoma, actinic keratosis and Bowen disease

This study aims at evaluating the expression of P27, Ki67 and P53 in Squamous Cell Carcinoma (SCC), Actinic Keratosis (AK) and Bowen Disease (BD) specimens. In an analytic-descriptive setting, skin biopsy specimens of 45 patients were evaluated in three 15-case groups including BD, AK and SCC specimens. Fifteen normal skin biopsy specimens were obtained and used as the control group. Immunohistochemical staining was performed in all the specimens and the expression rates and patterns of Ki67, P27 and P53 were determined. The results were compared between the four groups. Ki67 was expressed in 0.8, 23.7, 12.3 and 19.3% of the cells in the normal skin, AK, BD and SCC groups, respectively. No significant difference was seen between the three pathological conditions regarding the expression rate of Ki67. P27 was positive in 23.4, 26.2, 25.9 and 4.5% of specimens in the normal skin, AK, BD and SCC groups, respectively. This rate was significantly the lowest in the SCC group. P53 expression was detected in 26.6, 41.8 and 54.6% of the assessed cells in the AK, BD and SCC groups, respectively. There was no expression of P53 in the normal skin specimens. This rate was significantly the highest again in the SCC group. Based on these results, the quantitative and qualitative (pattern of distribution) evaluation of the expressions of Ki67, P27 and P53 may be helpful in differentiating malignant and premalignant epidermal lesions, particularly in unsatisfactory or fragmented specimens.

Identification of survivin, an inhibitor of apoptosis, in canine urinary bladder transitional cell carcinoma

Survivin, an inhibitor of apoptosis, is overexpressed in human invasive transitional cell carcinoma (TCC) of the urinary bladder. Survivin expression in canine TCC has not been defined. This study was designed to compare survivin expression between canine TCC and normal urinary bladder tissue. Reverse-transcriptase polymerase chain reaction (PCR) and immunohistochemistry (IHC) were performed on fresh-frozen and formalin-fixed tissues, respectively. All TCC tissues (n = 6) and 11/22 normal tissues assessed by PCR were positive for survivin. This difference was not significant (P = 0.06). With regard to IHC, 28/41 TCC samples were positive for nuclear survivin, whereas 0/46 normal tissues had nuclear immunoreactivity (P < 0.001). Cytoplasmic immunoreactivity did not significantly differ between TCC (7/41) and normal tissues (17/46) (P = 0.07). We conclude that nuclear survivin is present in canine TCC, but not in normal bladder urothelium. Future studies will evaluate the role of nuclear survivin in TCC development and as a potential therapeutic target.

Correlation between the levels of survivin and survivin promoter-driven gene expression in cancer and non-cancer cells

Survivin, a member of the inhibitor of apoptosis (IAP) protein family, is associated with malignant transformation and is over-expressed in most human tumors. Using lipoplex-mediated transfection, we evaluated the activity of the reporter enzyme, luciferase, expressed from plasmids encoding the enzyme under the control of either the cytomegalovirus (CMV) or survivin promoters, in tumor- and non-tumor-derived human and murine cells. We also examined whether there is a correlation between the survivin promoter-driven expression of luciferase and the level of endogenous survivin. Human cancer cells (HeLa, KB, HSC-3, H357, H376, H413), oral keratinocytes, GMSM-K, and chemically immortalized human mammary cells, 184A-1, were transfected with Metafectene at 2 μl/1 μg DNA. Murine squamous cell carcinoma cells, SCCVII, mouse embryonic fibroblasts, NIH-3T3, and murine immortalized mammary cells, NMuMG, were transfected with Metafectene PRO at 2 μl/1 μg DNA. The expression of luciferase was driven by the CMV promoter (pCMV.Luc), the human survivin promoter (pSRVN.Luc-1430), or the murine survivin promoters (pSRVN.Luc-1342 and pSRVN.Luc-194). Luciferase activity was measured, using the Luciferase Assay System and expressed as relative light units (RLU) per ml of cell lysate or per mg of protein. The level of survivin in the lysates of human cells was determined by ELISA and expressed as ng survivin/mg protein. In all cell lines, significantly higher luciferase activity was driven by the CMV promoter than by survivin promoters. The expression of luciferase driven by the CMV and survivin promoters in murine cells was much higher than that in human cells. The cells displayed very different susceptibilities to transfection; nevertheless, high CMV-driven luciferase activity appeared to correlate with high survivin-promoter driven luciferase expression. The survivin concentration in lysates of cancer cells ranged from 5.8 ± 2.3 to 24.3 ± 2.9 ng/mg protein (mean, 13.7 ng/mg). Surprisingly, elevated survivin protein was determined in lysates of non-tumor-derived cells. Survivin levels for GMSM-K and 184A-1 cells, were 16.7 ± 8.7 and 13.5 ± 6.2 ng/mg protein, respectively. The expression of endogenous survivin did not correlate with the level of survivin promoter-driven transgene activity in the same cells. The expression of survivin by non-tumorigenic, transformed cell lines may be necessary for their proliferative activity. The level of survivin promoter-driven gene expression achieved via liposomal vectors in OSCC cells was too low to be useful in cancer-cell specific gene therapy.

Cell growth inhibition and down-regulation of survivin by silibinin in a laryngeal squamous cell carcinoma cell line

OBJECTIVES

Abnormalities in the regulation of apoptotic cell death have been shown to have an important effect on the pathogenesis and progression of cancer. Survivin, which is identified in most cancers and has recently been identified as an inhibitor of apoptosis, is a potential therapeutic target for cancer management. We investigated cell growth, apoptosis, and expression of survivin in laryngeal squamous cell carcinoma cell lines after treatment with the bioactive compound silibinin.

METHODS

Cultured human laryngeal squamous cell carcinoma SNU-46 cells were treated with different concentrations of silibinin, and the degree of cell growth and apoptosis was analyzed. Additionally, survivin protein and messenger RNA were analyzed by Western immunoblotting and reverse transcription-polymerase chain reaction.

RESULTS

Silibinin inhibited the growth of SNU-46 cells in a both dose- and time-dependent manner (p < 0.01). Upon fluorescence-activated cell sorter analysis, silibinin (200 micromol/L) treatment increased the proportion of apoptotic cells from 7% to 40%. At high concentrations (more than 150 micromol/L), silibinin greatly reduced messenger RNA and protein expression of survivin.

CONCLUSIONS

Our findings demonstrate that silibinin induced apoptosis of laryngeal squamous carcinoma cells by a mechanism involving decreased survivin expression, which suggests the possibility that silibinin may be an effective treatment of laryngeal cancers.

Apoptosis and anti-apoptotic heat shock proteins in canine cutaneous infundibular keratinizing acanthomas and squamous cell carcinomas

Cell stress and death are linked in the neoplastic process, and heat shock proteins appear to play an important role by inhibiting apoptotic pathways. The apoptotic rates in 9 canine infundibular keratinizing acanthomas (IKAs) and 17 canine squamous cell carcinomas (SCCs) were correlated with the immunohistochemical expression of caspase-3 and the antiapoptotic heat shock proteins Hsp27, 72 and 73. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling (TUNEL) method. The absence of a correlation between the TUNEL index and active-caspase-3 expression, a paucity of active-caspase-3-positive cells and Hsp72 over-expression were considered to be indicative of inhibition of apoptosis, and suggestive that inhibition of cell death plays a key role in oncogenesis and tumour growth of some canine skin neoplasms.

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

PURPOSE

Survivin, an inhibitor of apoptosis protein and a cell cycle regulator, has been detected in the majority of human cancers. Five splice variants (survivin, survivin-2alpha, survivin-2B, survivin-3B, and survivin-DeltaEx3) have been identified; their expressions have been investigated here.

METHODS

By means of RT real-time PCR and immunohistochemistry, we have evaluated survivin isoform expressions at both mRNA and protein levels in human normal oral tissue, precancerous lesions, and oral squamous cell carcinoma (OSCC). Their correlations with the pathological findings have also been analyzed.

RESULTS

Expression levels of all survivin transcript variants were markedly elevated in OSCC when compared to normal tissues. One-way analysis of variance (ANOVA) revealed highly significant up-regulation of survivin (P = 0.001), survivin-DeltaEx3 (P = 0.001) and survivin-2B (P = 0.004), whereas survivin-3B showed a minor increase in OSCC compared to normal mucosa.

CONCLUSIONS

Our findings suggest that survivin isoforms deregulation may have significant implications in tumor aggressiveness and prognosis.

Expression of cIAP-1 correlates with nodal metastasis in squamous cell carcinoma of the tongue

Cellular inhibitor-of-apoptosis protein 1 (cIAP-1) is a member of the inhibitor-of- apoptosis protein family, which predominantly regulates apoptosis. It has been suggested that expression of cIAP-1 correlates with certain clinicopathological features. The possible significance of cIAP-1 expression in cervical lymph node metastasis of tongue squamous cell carcinoma (SCC) is investigated. Seventy-five tongue SCCs were analyzed by immunohistochemistry. cIAP-1 immunoreactivity patterns were nuclear in 38 (51%), cytoplasmic in 47 (63%), and concurrent in 37 (49%) cases. Nuclear, cytoplasmic and concurrent cIAP-1 immunoreactions were significantly correlated with lymph node metastasis in tongue SCCs (P=0.0011, 0.0012, and 0.0006, respectively). The cleaved caspase-3, which is a marker of tumor apoptosis, and Ki-67 index, which is a marker of tumor proliferation, were immunohistochemically examined in 21 tongue SCCs with concurrent nuclear and cytoplasmic cIAP-1 expression and with metastasis, and in 23 tongue SCCs without concurrent nuclear and cytoplasmic cIAP-1 expression and without metastasis. Concurrent cIAP-1 expression was inversely correlated with caspase-3 (P=0.0066), but was positively correlated with Ki-67 expression (P=0.0028). The mode of invasion was associated with lymph node metastasis (P=0.014) and differentiation (P=0.013), but was not correlated with cIAP-1 expression. There was no statistically significant correlation between nuclear or cytoplasmic cIAP-1 expression and the clinicopathological factors of gender, age, clinical stage or differentiation. These results suggest that both patterns of cIAP-1 are useful markers for predicting cervical lymph node metastasis in tongue SCC.

Silver-stained nucleolar organizer regions and immunoglobulins in cutaneous squamocellular tumors

This study was conducted to elucidate the biological activity of epidermal cells in cutaneous squamocellular tumors by counting the number of silver-stained nucleolar organizer regions (AgNORs), to estimate the quantity of Ig-producing cells and the inflammatory cellular infiltrate (ICI), and to achieve a comparative evaluation. Twenty cases of actinic keratosis (AK), 20 in situ squamous cell carcinomas (ISC), and 20 invasive squamous cell carcinomas (SCCs) were assessed using a silver colloid technique. Ig-producing or binding cells and ICI were also investigated immunohistochemically. In all samples, AgNORs, Ig-producing cells, and ICI increased in proportion to the degree of malignancy. With regard to AgNORs values, a statistically significant difference was confirmed between AK and ISC (p<0.01), AK and SCC (p<0.001), and ISC and SCC (p<0.05). IgG-producing cells predominated in each case. Furthermore, a linear correlation was detected between ICI and AgNORs in AK and ISC. The significant difference in the number of AgNORs among the 3 stages of involution of SCC reinforces the value of AgNORs as a marker for malignant potential. Despite the absence of a correlation between AgNORs and the proportion of Ig-producing cells, the association between ICI and AgNORs in AK and ISC was obvious.

Gene expression levels of epidermal growth factor receptor, survivin, and vascular endothelial growth factor as molecular markers of lymph node involvement in patients with locally advanced rectal cancer

BACKGROUND

Patients diagnosed with locally advanced rectal cancer usually receive surgical resection and adjuvant chemoradiation therapy. Lymph node involvement is an important clinical prognostic factor affecting recurrence and survival. Few studies have explored molecular markers associated with lymph node involvement of rectal cancer.

PATIENTS AND METHODS

Tissue was obtained from 59 patients with locally advanced rectal cancer who were treated with adjuvant chemoradiation therapy. We assessed messenger RNA (mRNA) levels of genes involved in pathways of angiogenesis (vascular endothelial growth factor [VEGF], cyclooxygenase-2), apoptosis (survivin), tumor growth and epidermal growth factor receptor (EGFR), DNA repair (ERCC1, Rad51), and the DNA synthesis in tumor tissue and tumor-adjacent normal tissue from paraffin-embedded samples using laser-capture microdissection methods.

RESULTS

Twenty-four patients had no involvement of regional lymph nodes and 35 had lymph node metastases. In univariate analysis, patients with lymph node involvement had higher mRNA levels of VEGF and survivin in tumor tissue and EGFR in tumor-adjacent normal tissue compared with patients with no lymph node involvement (P < 0.1; t test). Multivariate analysis using recursive partitioning showed that mRNA levels of EGFR, survivin, and Rad51 are primarily responsible for delineating node positive from node negative.

CONCLUSION

Gene expression of VEGF, survivin, and EGFR could be associated with lymph node involvement in patients with locally advanced rectal cancer. Further independent studies of those gene expression levels and lymph node involvement are warranted to better characterize the associations.

Expression of survivin and XIAP for DMBA-induced hamster buccal pouch squamous cell carcinogenesis is associated with p53 accumulation

Apoptosis (programmed cell death) is regulated by a number of inhibitory or stimulatory factors. One such family of antiapoptotic proteins is the inhibitors of apoptosis proteins (IAPs), of which survivin and X chromosome-linked IAP (XIAP) are members. The expression of survivin and XIAP, as well as their association with p53, in chemically-induced experimental oral carcinogenesis is not completely understood. The objective of the present study was, therefore, to investigate the protein expression of these two IAP family members and their relationship with p53 status, in 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch squamous cell carcinogenesis. Immunohistochemical analysis of survivin, XIAP and p53 protein expression was performed in DMBA-induced pouch squamous cell carcinogenesis. Fifty outbred, young (6 weeks), male Syrian golden hamsters (Mesocricatus auratus) were randomly divided into three experimental groups (each group consisting of 10 animals treated with DMBA for 3-, 7- or 14-weeks), and two control groups (with 10 animals in each). The pouches of the three experimental groups were painted bilaterally with a 0.5% DMBA solution three times a week. The treatment protocol for animals in one of the control groups was identical with only mineral oil applied, while the other control group remained untreated throughout the experiment. Survivin staining could not be detected by immunohistochemistry in any of the untreated or mineral oil treated hamster pouch-tissue specimens. Cytoplasmic staining of survivin proteins was apparent in the entire epithelial layer (excluding the keratinized layer) in all 3-week DMBA treated pouch-tissue analyzed. In addition, cytoplasmic survivin staining was observed in all specimens of 7- and 14-week DMBA treated pouch-tissue. XIAP positivity was confined to the outermost keratinized layer of the pouch-tissue from control animals and those treated with DMBA for 3-weeks. However, XIAP staining was detected in the whole epithelial layer (except the basal layer) in 7- and 14-week DMBA treated pouch-tissue. p53 was not detected in any untreated and mineral oil treated pouch-tissue, whereas nuclear p53 staining was observed for all 3-, 7- and 14-week DMBA treated pouch-tissue. The results of this study demonstrate the association between survivin/XIAP and p53 expression in this experimental model system for oral carcinogenesis, although their exact interactions remain to be clarified. Moreover, our findings suggest that the DMBA-induced hamster buccal pouch mucosa may serve as an appropriate experimental model for investigation of potential novel therapeutic tools for oral squamous-cell carcinomas.

Increased survivin expression in high-grade oral squamous cell carcinoma: a study in Indian tobacco chewers

BACKGROUND

Oral cancer is one of the five leading sites of cancer in the Indian population. In the present study we analyzed the expression of apoptosis regulating genes, viz. survivin, Bcl-2, Bax and p53 in precancerous and cancerous lesions of the buccal mucosa of Indian tobacco chewers.

METHOD

Paraffin-embedded tissue samples from 38 patients with primary oral squamous cell carcinoma (OSCC) and 17 patients with leukoplakia were used. The expression of survivin, Bcl-2, Bax, and p53 was evaluated using immunohistochemical staining method.

RESULTS

Thirty-six percent OSCC were found to be positive for nuclear p53 staining while none of the precancerous lesions showed p53 positivity. Survivin, Bcl-2 and Bax expression was found to increase with increased grade of malignancy. Increase in survivin expression was statistically most significant (P < 0.001).

CONCLUSION

Increased expression of anti-apoptotic survivin in high-grade tumors suggests that survivin is likely to contribute significantly to apoptosis resistance in response to therapy.

Immunohistochemical analysis of nuclear survivin expression in esophageal squamous cell carcinoma

Despite advances in the treatment of esophageal carcinoma, the prognosis for this disease remains poor. Therefore, it is important to obtain a better understanding of the molecular basis of esophageal carcinogenesis. The purpose of this study was to clarify the roles of survivin in esophageal squamous cell carcinoma (ESCC). One hundred 22 ESCC surgical specimens resected from 1989 to 1999 were examined. Survivin expression was assessed by immunohistochemistry. Tumor cells were considered survivin-positive if the immunoreactivity was confined to the nucleus, and a scoring method was applied. Survivin-positive immunostaining was detected in 68 patients (56%). There was a significant association between survivin expression and pN (P = 0.0472). Moreover, the overall survival rate was worse in patients with survivin-positive tumors than in patients with survivin-negative tumors (P = 0.0189). The overexpression of survivin was associated with the overall survival rate and poor prognosis in patients with ESCC. Survivin may be targeted during cancer therapy because of its selective expression in malignant tissue.

Keratinocyte apoptosis in epidermal development and disease

Keratinocyte (KC) apoptosis plays a critical role in regulating epidermal development and restraining carcinogenesis. Apoptosis balances proliferation to maintain epidermal thickness, contributes to stratum corneum formation and may eliminate pre-malignant cells. Apart from the normal developmental program, KC apoptosis can be triggered by UV light and other stimuli. Dysfunctional apoptosis occurs in some skin diseases, such as psoriasis and skin cancer. Here we review the current state of knowledge of KC apoptosis, with particular focus on apoptotic signaling pathways and molecular mechanisms of apoptosis control, and discuss new insights into the complex role of apoptosis in skin carcinogenesis that are emerging from mouse models.