Expression of the antiapoptosis gene, survivin, predicts death from recurrent colorectal carcinoma

Increased ROS generation and p53 activation in α-lipoic acid-induced apoptosis of hepatoma cells

Alpha-lipoic acid (alpha-LA) is an antioxidant used for the treatment of a variety of diseases, including liver cirrhosis, heavy metal poisoining, and diabetic polyneuropathy. In addition to its protective effect against oxidative stress, alpha-LA induces apoptosis in different cancer cells types. However, whether alpha-LA acid induces apoptosis of hepatoma cells is unknown. Herein, we investigated whether alpha-LA induces apoptosis in two different hepatoma cell lines FaO and HepG2. The results showed that alpha-LA inhibits the growth of both cell lines as indicated by the reduction in cell number, the reduced expression of cyclin A and the increased levels of the cyclin/CDKs inhibitors, p27(Kip1) and p21(Cip1). Cell cycle arrest was associated with cell loss, and DNA laddering indicative of apoptosis. Apoptosis was preceded by increased generation of reactive oxygen species, and associated with p53 activation, increased expression of Bax, release of cytochrome c from mitochondria, caspases activation, decreased levels of survivin, induction of pro-apoptotic signaling (i.e JNK) and inhibition of anti-apoptotic signaling (i.e. PKB/Akt) pathways. In conclusion, this study provides evidence that alpha-LA induces apoptosis in hepatoma cells, describes a possible sequence of molecular events underlying its lethal effect, and suggests that it may prove useful in liver cancer therapy.

Nuclear localization of Survivin renders HeLa tumor cells more sensitive to apoptosis by induction of p53 and Bax

Clinical studies have shown that nuclear expression of the inhibitor of apoptosis protein Survivin in tumor cells predicted a favorable prognosis whereas cytosolic-localized protein caused a decreased overall survival. Therefore Survivin's subcellular localization may be important for its anti-apoptotic capacity. To address this question, we investigated localization and function of Survivin in normal human lung fibroblasts (NHLFs) and HeLa tumor cells. NHLFs of early passages expressed Survivin in the nucleus and were highly sensitive to C2 ceramide, which induces the mitochondrial apoptotic pathway. In contrast, NHLFs at higher passages relocated Survivin to the cytosol and became more resistant to C2 ceramide. Blocking nuclear export of Survivin by leptomycin B in HeLa cells increased susceptibility to C2 ceramide. In addition, transduction of HeLa cells with Survivin fused to a nuclear localization signal augmented basal expression levels of p53 and Bax and enhanced sensitivity for intrinsic apoptosis. Those findings suggest that a predominant nuclear localization of Survivin increases the sensitivity for pro-apoptotic stimuli, whereas nuclear export enables Survivin to fulfill its inhibitor of apoptosis function. A therapeutic intervention which holds Survivin in the nucleus of tumor cells might improve cancer therapy.

Targeted gene therapy for breast cancer with truncated Bid

We studied the efficiency of the proapoptotic factor tBid, targeted to tumor cells using the promoters of the hTERT, Survivin and Muc1 genes, in killing breast cancer cells. tBid is the active fragment of the proapoptotic protein Bid and is generated in response to death receptor activation. When placed under control of a strong CMV promoter, tBid was highly efficient in killing breast cancer cells. When expression of tBid was driven by tumor-specific promoters, the magnitude of killing was significant in cell lines with high levels of promoter activity. For successful gene therapy with targeted tBid, it is therefore crucial to be able to predict promoter activity prior to selection of the therapeutic construct. To test whether gene expression could serve as a predictor, we correlated expression of Survivin, hTERT and Muc1 genes with the activity of the corresponding promoters in a panel of breast cancer cell lines. Expression of the Muc1 gene correlated well with the activity of its promoter and the resultant tumor cell killing. For the hTERT and Survivin promoters, however, promoter activity did not correlate well with the expression of the corresponding genes. The implications and possible mechanism of these discrepancies are discussed.

Survivin, a cancer target with an emerging role in normal adult tissues

Survivin, an inhibitor of apoptosis protein, is highly expressed in most cancers and associated with chemotherapy resistance, increased tumor recurrence, and shorter patient survival, making antisurvivin therapy an attractive cancer treatment strategy. However, growing evidence indicates that survivin is expressed in normal adult cells, particularly primitive hematopoietic cells, T lymphocytes, polymorphonuclear neutrophils, and vascular endothelial cells, and may regulate their proliferation or survival. In preclinical animal models, targeted antisurvivin therapies show efficacy without overt toxicity. However, consequences of prolonged survivin disruption in normal cells, particularly those associated with continuous renewal, have not been clearly determined. Understanding the role of survivin in normal versus malignant cells will be important in identifying strategies that maximally disrupt survivin in cancer cells with minimal effect on normal tissues. In this review, we summarize the prognostic relevance of survivin in cancer that justifies the pursuit of antisurvivin therapies and discuss differences in survivin expression between normal and cancer cells. We subsequently review expression of survivin in normal adult tissues and evaluate preclinical antisurvivin therapies reported to date in light of emerging roles for survivin in normal physiology, particularly hematopoiesis, angiogenesis, and immune function.

Survivin as a prognostic factor for osteosarcoma patients

Purpose: Survivin is one of the apoptosis inhibitor genes and is rarely expressed in adult ­tissues. However, survivin expression has been detected in various human cancers and ­correlations have been recognized between the level of expression of this gene in tumors and prognosis. In this study, we investigated the correlations between survivin mRNA expres­sion in osteosarcoma tissues and clinicopathological parameters.

Methods: There were 22 osteosarcoma patients in our hospital with paraffin-embedded ­tissues which could be extracted from biopsy specimens. We used the RT-PCR method after extracting total RNA and conducted a densitometric analysis to determine the ratio of survivin relative to h-GAPDH as an internal marker.

Results: Expression of survivin mRNA was detected in all osteosarcoma samples. Patients with metastasis had high survivin mRNA levels in initial biopsy specimens (p<0.01). Moreover, there was a statistically significant difference in survivin mRNA expression between ­patients with and without metastasis (p<0.01).

Conclusion: We concluded that high levels of survivin mRNA expression suggest poor prognosis for osteosarcoma patients.

A retrogen plasmid-based vaccine generates high titer antibody responses against the autologous cancer antigen survivin and demonstrates anti-tumor efficacy

We describe the use of retrogen plasmid-based vaccine technology to break tolerance and to generate a robust, dose-dependent antibody response against the self cancer antigen, survivin. We further demonstrate that this phenomenon is due to the incorporation of the survivin antigen into the retrogen system rather than to some peculiarity unique to survivin. In contrast to other genetic immunization methods designed to produce antibody responses, the retrogen system results in a broad range of antibody isotypes, indicative of both a Th-1 and a Th-2 CD4+ response. Additional evidence of a Th-1 response is demonstrated by tumor growth inhibition in a mouse model of colon cancer metastasis. We speculate that this cost-effective technology could one day bolster or even supplant the use of monoclonal antibodies in the targeting of cell surface cancer antigens.

Down-regulation of survivin expression by small interfering RNA induces pancreatic cancer cell apoptosis and enhances its radiosensitivity

AIM: To investigate the inhibitory effect of small interfering RNA (siRNA) on the expression of survivin in pancreatic cancer cell line PC-2 and the role of siRNA in inducing PC-2 cell apoptosis and enhancing its radiosensitivity.

METHODS: A siRNA plasmid expression vector against survivin was constructed and transfected into PC-2 cells with Lipofectamine^TM 2000. The down regulation of survivin expression was detected by semi-quantitive RT-PCR and immunohistochemical SP method and the role of siRNA in inducing PC-2 cell apoptosis and enhancing its radiosensitivity was detected by flow cytometry.

RESULTS: The sequence-specific siRNA efficiently and specifically down-regulated the expression of survivin at both mRNA and protein levels. The expression inhibition ratio was 81.25% at mRNA level detected by semi-quantitive RT-PCR and 74.24% at protein level detected by immunohistochemical method. Forty-eight hours after transfection,apoptosis was induced in 7.03% cells by siRNA and in 14.58% cells by siRNA combined with radiation.

CONCLUSION: The siRNA plasmid expression vector against survivin can inhibit the expression of survivin in PC-2 cells efficiently and specifically. Inhibiting the expression of survivin can induce apoptosis of PC-2 cells and enhance its radiosensitivity significantly. RNAi against survivin is of potential value in gene therapy of pancreatic cancer.

High-level expression, purification and pro-apoptosis activity of HIV-TAT-survivin (T34A) mutant to cancer cells in vitro

Survivin, a novel member of the IAP family, was observed to express in the most common human cancers. Anti-cancer therapy targeting survivin had drawn considerable attention. This study focused on high-level expression of recombinant protein TAT-survivin (T34A) mutant in E. coli, purification and bioactivity of pro-apoptosis to various cell lines in vitro. The cDNA encoding survivin was cloned by RT-PCR from breast cancer cell lines B-cap37. After PCR site-directed mutagenesis and construction of expression vector pRSET-B-TAT-survivin (T34A), targeted TAT-survivin (T34A) protein was expressed highly in E. coli BL21 (DE3) by 0.5mM IPTG induction and its yield could reach 650 mg/l in fermentation culture. The fusion protein in a form of inclusion body was then solubilized, refolded and purified to a purity of 98% by cation exchange chromatography and size-exclusion chromatography. Four hundred and eighty milligrams protein of interest was obtained in per liter fermentation culture. This showed that the efficient procedures of large-scale expression and purification were successful for the mass production of the recombinant protein. Pro-apoptosis effects of target protein on four cancer cell lines and one normal cell line from human were confirmed by the change of morphology, and pro-apoptosis activity was evaluated by MTT, fluorescent staining of nuclei and flow cytometry assay. Results indicated that B-cap37 and SW1990 were very sensitive to TAT-survivin (T34A) protein. This finding revealed the recombinant protein was promising as an anti-cancer drug.

Differential c-erbB-1 and c-erbB-2 mRNA expression in cancer of the pancreas compared with cancer of the papilla of Vater

AIM: We examined quantitative mRNA expression of growth factor receptors (c-erbB-1, c-erbB-2) and the anti-apoptosis gene survivin known to be regulated in pancreatic adenocarcinomas and compared the expression pattern with that in carcinomas of the papilla of Vater.

METHODS: Quantitative real-time reverse transcriptase-PCR (QRT-PCR, Taqman^TM) was performed to analyze mRNA expression levels of c-erbB-1, c-erbB-2 and survivin in normal and corresponding tumor samples of 31 pancreatic adenocarcinomas and 8 cancers of the papilla of Vater.

RESULTS: The overall median mRNA expression of survivin was significantly increased in both adenocarcinoma of the pancreas (P<0.01) and papilla of Vater (P<0.008) compared with uninvolved normal control tissue. In pancreatic cancer, expression of c-erbB-1 was significantly decreased compared with the normal pancreatic tissue (P<0.03), whereas in the cancer of the papilla of Vater expression of c-erbB-2 was significantly downregulated (P<0.05) compared with the paired normal samples. Gene expression was not associated with tumor stage, differentiation or prognosis.

CONCLUSION: The common anti-apoptosis gene survivin is overexpressed both in the cancer of the papilla of Vater and pancreas. In contrast, the growth factor receptor genes c-erbB-1 and c-erbB-2 are differentially regulated in both tumor entities adding further evidence that pancreatic cancer is biologically different from the cancer of papilla of Vater.

Survivin expression in breast cancer predicts clinical outcome and is associated with HER2, VEGF, urokinase plasminogen activator and PAI-1

BACKGROUND

Survivin, a novel inhibitor of apoptosis, is one of the most cancer-specific proteins identified to date. In this study we (a) evaluated the association between survivin and HER2, vascular endothelial growth factor (VEGF) and uPA/PAI-1 expression and (b) defined its effect on clinical outcome in a large breast cancer patient cohort.

PATIENTS AND METHODS

Survivin expression was measured by ELISA in primary breast cancer tissue extracts from 420 patients with long-term clinical follow-up.

RESULTS

Survivin was detected in 378 (90%) of the 420 primary breast cancer cases. Increased survivin levels were significantly associated with high nuclear grade (P < 0.0001), negative hormone receptor status (P = 0.0028), HER2 overexpression (P = 0.0094), VEGF expression (P < 0.0001), high uPA (P = 0.0002) and PAI-1 levels (P = 0.0002). Using the 25th percentile (1.4 ng/mg) as a cut-off point, patients expressing elevated survivin had a significantly worse disease-free survival (DFS: P = 0.0007, RR 1.97) and overall survival (OS: P = 0.0009, RR 2.11) compared with patients expressing lower levels of survivin. In multivariate analysis, this prognostic value of survivin was independent of both traditional and novel clinicopathologic factors for both DFS (P = 0.0076, RR 1.72) and OS (P = 0.0155, RR 1.76).

CONCLUSIONS

The independent prognostic relevance of survivin, when combined with previous data from model systems implicating survivin in the inhibition of apoptosis, suggests that survivin may be a suitable target for future therapeutic strategies.

Nuclear expression of the antiapoptotic protein survivin in malignant melanoma

BACKGROUND

Expression of the antiapoptotic protein survivin has been demonstrated in some melanocytic lesions and is believed to be required for melanoma cell viability. However, its diagnostic value in differentiating melanomas from nevi has not yet been examined.

METHODS

Tissue microarray blocks were constructed with paraffin-fixed tissue of 19 nevi, 18 dysplastic nevi, 24 malignant melanomas, and 31 metastatic melanomas. Sections were then reacted with three antisurvivin antibodies (two monoclonal and one polyclonal) assessing labeling intensity (absent or weak, and moderate to strong) as well as the percentage of cells labeled (< 25%, > or = 25%).

RESULTS

Of the antibodies evaluated, the polyclonal one was found to be the most sensitive. Nuclear immunoreactivity for survivin (i.e., > or = 25% of cells exhibiting and/or at least moderately intense staining) was seen in a subset of melanomas but not in nevi or dysplastic nevi (P < 0.05).

CONCLUSIONS

Survivin is variably expressed in the cytoplasm in the entire spectrum of melanocytic lesions, with nuclear expression detectable only in melanomas. These data may underscore the importance of nuclear survivin in progression to melanoma and may prove useful in the differential diagnosis of melanoma versus nevus.

Reg IV activates the epidermal growth factor receptor/Akt/AP-1 signaling pathway in colon adenocarcinomas

BACKGROUND & AIMS

Reg IV, a secreted protein and member of the Reg multigene family, is up-regulated in malignancies of the human gastrointestinal tract, including colorectal carcinoma (CRC). However, in vitro signal transduction pathway(s) utilized by Reg IV are not yet known.

METHODS

To determine the signaling pathway(s) responsive to Reg IV, we examined the effects of purified recombinant human Reg IV (rhR4) on HCT116 and HT29 colon adenocarcinoma cells.

RESULTS

Addition of rhR4 to cultures led to a dose-dependent increase in cell number similar to that observed after treatment with epidermal growth factor (EGF). In addition, rhR4 treatment resulted in rapid phosphorylation of EGF receptor at Tyr992 and Tyr1068 and Akt at Thr308 and Ser473. Using luciferase reporter gene assays, we demonstrated that Reg IV signaling through EGF receptor and Akt results in increased activator protein-1 (AP-1) transcription factor activity. Real-time reverse-transcription polymerase chain reaction and Western blot analyses revealed quantitative increases in c-Jun, JunB, JunD, and FosB expression associated with increased AP-1 activity. Electrophoretic mobility shift assay further revealed significant increases in AP-1 binding activity in rhR4-treated cells, with increased supershift in the presence of antibodies to JunB, JunD, and FosB. Furthermore, rhR4 treatments led to the increased expression of Bcl-2, Bcl-XL, survivin, and matrilysin, genes associated with a poor prognosis in advanced CRC.

CONCLUSIONS

Reg IV is a potent activator of the EGF receptor/Akt/AP-1 signaling pathway in CRC. Disruption of Reg signaling may have utility as a therapeutic intervention for human gastrointestinal adenocarcinomas.

Survivin expression by metastatic melanoma predicts poor disease outcome in patients receiving adjuvant polyvalent vaccine

Survivin and livin are members of the inhibitor of apoptosis protein (IAP) family. We hypothesized that elevated expression levels of these 2 IAP genes in resected advanced-stage metastatic melanoma lesions would be associated with poor disease outcome in patients receiving a polyvalent therapeutic cancer vaccine (Canvaxintrade mark). A quantitative real-time RT-PCR (qRT) assay for survivin and livin genes was used to assess mRNA expression in 63 metastatic melanomas obtained during cytoreductive surgery of American Joint Committee on Cancer (AJCC) stage IV melanoma. Nineteen of 63 metastatic melanoma patients received Canvaxin pre- and postoperatively, and 37 patients received only postoperative Canvaxin. Expression of survivin and livin protein was assessed by immunohistochemistry (IHC) and then correlated with mRNA. Survivin mRNA was detected in 62 of 63 (98%) melanoma specimens ranging from 0-5.96 x 10(4) mRNA copies of total RNA. Lower mRNA copy levels of survivin significantly correlated with improved overall survival among the 37 patients who received Canvaxin postoperatively but not preoperatively (log-rank test, p = 0.023). Among patients with low survivin mRNA copies, those who received postoperative Canvaxin did significantly better than patients who received pre- and postoperative Canvaxin (p = 0.003). Livin mRNA was detectable in 60 of 63 (95%) metastatic melanoma specimens but had no significant prognostic utility. These studies demonstrate that lower levels of survivin in recurrent metastatic melanomas are associated with significantly improved survival in patients receiving postoperative adjuvant immunotherapy. Overall, the study indicates survivin expression in metastatic melanomas can significantly influence disease outcome and patient responses to immunotherapy.

Apoptosis: a basic biological phenomenon with wide-ranging implications in human disease

Apoptosis is a highly regulated process of cell deletion and plays a fundamental role in the maintenance of tissue homeostasis in the adult organism. Numerous studies in recent years have revealed that apoptosis is a constitutive suicide programme expressed in most, if not all cells, and can be triggered by a variety of extrinsic and intrinsic signals. Many human diseases can be attributed directly or indirectly to a derangement of apoptosis, resulting in either cell accumulation, in which cell eradication or cell turnover is impaired, or cell loss, in which the apoptotic programme is inadvertently triggered. In addition, defective macrophage engulfment and degradation of cell corpses may also contribute to a dysregulation of tissue homeostasis. An increased understanding of the signalling pathways that govern the execution of apoptosis and the subsequent clearance of dying cells may thus yield novel targets for therapeutic intervention in a wide range of human maladies.

Survivin expression in ganglioglioma

Gangliogliomas are unusual central nervous system (CNS) neoplasms occurring mainly in children and young adults and inducing chronic pharmacoresistant epilepsy. These are usually well differentiated neuroepithelial tumors composed of neurons in association with neoplastic glial cells. Gangliogliomas present with favorable outcome. However, some may recur and/or progress to anaplasia and be associated with a dismal prognosis. Since histopathological features do not consistently correlate with clinical outcome, reliable prognostic factors have yet to be defined in gangliogliomas. Survivin is an anti-apoptotic protein whose expression has been found to be of prognostic significance in many human cancers, including gliomas. The objective of this study was to assess survivin expression using immunohistochemistry in 15 gangliogliomas. Ten lesions were low-grade neoplasms whereas 5 were high-grade tumors. Survivin expression appeared restricted to the neoplastic glial component and was detected in 6/15 gangliogliomas. Two additional tumors expressed survivin upon relapse. Half survivin expressing lesions displayed less than 1% immunoreactive cells. Survivin expression in more than 5% neoplastic glial cells was detected only in malignant and/or recurrent gangliogliomas. Extended lifespan in survivin expressing cells might enhance aggressive behavior in these tumors through accumulation of mutations, thereby allowing progression to malignant phenotypes. Survivin expression may carry a negative prognostic value in gangliogliomas.

Regulation of survivin expression through Bcr-Abl/MAPK cascade: targeting survivin overcomes imatinib resistance and increases imatinib sensitivity in imatinib-responsive CML cells

KBM5 cells, derived from a patient with blast crisis Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML), and imatinib-resistant KBM5 (KBM5-STI571) cells were found to express high levels of survivin. Inhibition of Bcr-Abl by imatinib significantly decreased survivin expression and cell viability in KBM5, but much less so in KBM5-STI571 cells. Inhibition of MEK, downstream of the Bcr-Abl signaling cascade decreased survivin expression and cell viability in both KBM5 and KBM5-STI571 cells. In addition, down-regulation of survivin by a survivin antisense oligonucleotide (Sur-AS-ODN) inhibited cell growth and induced maximal G2M block at 48 hours, whereas cell death was observed only at 72 hours in both KBM5 and KBM5-STI571 cells as shown by annexin V staining. Further, the combination of Sur-AS-ODN and imatinib induced more cell death in KBM5 cells than did either treatment alone. Down-regulating survivin also decreased colony-forming units (CFUs) in blast crisis CML patient samples. Our data therefore suggest that survivin is regulated by the Bcr-Abl/MAPK cascade in Ph+ CML. The facts that down-regulating survivin expression induced cell-growth arrest and subsequent cell death regardless of the cell response to imatinib and enhanced the sensitivity to imatinib suggest the potential therapeutic utility of this strategy in patients with CML, both imatinib sensitive and resistant.

Construction, expression, and purification of HIV-TAT-survivin (T34A) mutant: a pro-apoptosis protein in Escherichia coli

As a novel member of the IAP family, survivin was observed to express in the most common human cancers. Anti-cancer therapy targeting survivin has drawn considerable attention. This report presented firstly construction of recombinant plasmid pRSET-B-TAT-survivin (T34A), expression in Escherichia coli, purification, renaturation, and bioactivity. The cDNA encoding survivin was cloned by RT-PCR from breast cancer cell lines B-cap37. Expression vector pRSET-B-TAT-survivin (T34A) was constructed by PCR after survivin was mutated by PCR site-directed mutagenesis. Recombinant TAT-survivin (T34A) protein was expressed highly in E. coli BL21 (DE3) by 0.5 mM IPTG induction and its yield could reach 650 mg/l in fermentation culture. The fusion protein in a form of inclusion body was then solubilized, refolded, and purified to a purity of 98% by cation exchange chromatography and size-exclusion chromatography. Four hundred and eighty milligrams protein of interest was obtained in per liter fermentation culture. The protein of interest was identified by SDS-PAGE and Western blot analysis, and great bioactivity of target protein to two cancer cell lines was confirmed by morphological changes and evaluated by MTT. The findings suggested that recombinant protein TAT-survivin (T34A) has a bright future in cancer therapy targeting towards survivin, and the efficient procedure of expression and purification may be useful for the mass production of this therapeutically important protein.

Significance of survivin and caspase-3 protein expression in gastric precancerous lesions and gastric cancer tissue

AIM: To detect the expression survivin and caspase-3 in the tissues of gastric cancer and precancerous lesion, and to explore their roles in the carcinogenesis gastric cancer.

METHODS: The expression of survivin and caspase-3 protein were detected by Envision immunohistochemistry in 131 cases of paraffin-embedded specimens from different gastric mucosa, including 44 cases of chronic gastritis, 31 cases of intestinal metaplasia, 40 cases of dysplasia and 16 cases of gastric cancer.

RESULTS: The positive rates of survivin expression in chronic gastritis, intestinal metaplasia, dysplasia and gastric cancer were 4.5%(2/44), 51.6%(15/31), 100.0%(40/40) and 93.8%(15/16) respectively. The positive rates of survivin protein in gastric cancer and dysplasia were significantly higher than that in intestinal metaplasia(P<0.05). The level of caspase-3 expression in positive survivin groups was significantly lower than in negative survivin group(23.1% vs 66.7%, P<0.05).

CONCLUSION: The positive rate of survivin protein in gastric cancer is similar to that in dysplasia, and higher than that in intestinal metaplasia. Survivin may promote the progression of gastric cancer by inhibiting the expression of caspase-3.

Expression of a novel apoptosis inhibitor-survivin in colorectal carcinoma

AIM: To investigate the role of survivin expression in the pathogenesis of colorectal carcinoma.

METHODS: Immunohistochemistry S-P method and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) were used to detect the expression of survivin and apoptotic cell in situ in colorectal cancerous tissues, para-cancerous tissues and normal tissues of 48 cases of colorectal carcinoma.

RESULTS: The survivin positive unit (PU) was higher in cancerous tissues (38.76 ± 5.14) than in para-cancerous (25.17 ± 7.26) or normal tissues (0.57 ± 0.03) (P < 0.05). The apoptosis index (AI) of para-cancerous tissues was (7.51 ± 2.63%) higher than cancerous tissues (4.65 ± 1.76%). The expression of survivin was associated with pathological grade, lymph node metastasis and Dukes stage of colorectal carcinoma.

CONCLUSION: Survivin expression may play an important role in carcinogenesis of colorectal carcinoma and may be associated with malignant biological behaviors of colorectal carcinoma.

Survivin as a radioresistance factor, and prognostic and therapeutic target for radiotherapy in rectal cancer

Apoptosis levels have been shown to predict tumor response to preoperative radiochemotherapy in rectal cancer. Recently, the prominent role of survivin, a structurally unique member of the inhibitor of apoptosis protein family, has been shown in colorectal cancer tumorigenesis and prognosis. In this study, we investigated whether survivin plays a direct role in mediating radiation resistance. We used short interfering RNA molecules to decrease survivin in radioresistant SW480 and intermediately radioresistant HCT-15 colorectal cancer cells. This resulted in a significant decrease of survivin mRNA and protein expression with a maximum at 24 to 48 hours after transfection. If irradiated during this sensitive period, an increased percentage of apoptotic cells and an increased caspase 3/7 activity in parallel with a decreased cell viability and a reduced clonogenic survival was shown. These effects were more pronounced in the radioresistant SW480 cell line with a radiation-induced cytotoxicity enhancement factor at 10% and 50% survival of 1.8 to 2.2 for SW480 and 1.5 to 1.7 for HCT-15, respectively. Furthermore, transfection with survivin short interfering RNA increased levels of G2-M arrest and levels of DNA double-strand breaks in irradiated cells. These observations indicate that cell cycle and DNA repair mechanisms may be associated with apoptosis induction in tumor cells that are otherwise resistant to killing by radiation. In a translational study of 59 patients with rectal cancer treated with a combination of radiotherapy and chemotherapy, increased survivin expression was inversely related to the levels of apoptosis, and was also associated with a significantly higher risk of a local tumor recurrence.

Nuclear expression of cIAP-1, an apoptosis inhibiting protein, predicts lymph node metastasis and poor patient prognosis in head and neck squamous cell carcinomas

cIAP-1, an apoptosis inhibiting protein, has been suggested to play important roles in the development of cervical and esophageal squamous cell carcinomas (SCCs). In order to clarify the subcellular localization of cIAP-1 and to investigate its clinicopathological significance in head and neck SCCs (HNSCCs), we examined cIAP-1 expression in four oral SCC cell lines by immunocytochemistry and Western blot. Expressions of nuclear and cytoplasmic cIAP-1, caspase-3, and Smac/DIABLO were also examined immunohistochemically in 57 cases of the HNSCCs. cIAP-1 expression was detected in HSC-2, HSC-3, and HSC-4 cells by immunohistochemistry and Western blot. In HSC-2 and HSC-4 cells, cIAP-1 was detected in both the nuclear and cytoplasmic fractions. Nuclear cIAP-1 expression was positive in 17 (30%) of HNSCCs, was correlated with lymph node metastasis (P=0.020) and advanced disease stage (P=0.032), and tended to be correlated with poor patient prognosis (P=0.059). Cytoplasmic cIAP-1 expression showed similar but weaker clinicopathological correlations. Nuclear cIAP-1 expression was inversely correlated with caspase-3 expression, but was correlated with Smac/DIABLO expression. Nuclear cIAP-1 expression appears to be a useful marker for predicting poor patient prognosis in HNSCCs, and may play roles in HNSCCs through the signaling pathway mediated by Smac/DIABLO and caspase-3.

Detection of autoantibodies to survivin and livin in sera from patients with breast cancer

BACKGROUND

Survivin and livin are highly expressed in cancer cells and transformed cells, but show little or no expression in normal differentiated tissues. Human antibody responses to tumor-associated antigens have been detected, but little is known about the response to survivin and livin in breast cancer patients.

METHODS

We examined the prevalence of anti-survivin and livin antibodies in breast cancer patients with a specific enzyme-linked immunosorbent assay (ELISA) using recombinant protein.

RESULTS

Using a cutoff value for positivity determined as the mean absorbance +2SD for healthy control samples, sera from 11 of 46 breast cancer patients (23.9%) were positive by the ELISA using recombinant survivin protein. Of 46 samples from the same breast cancer patients, 15 (32.6%) were positive for anti-livin antibodies. In addition, 24 (52.2%) were positive for 1 or both ELISAs using the respective proteins. Intensity of anti-livin antibody responses did not correlate with intensity of anti-survivin responses.

CONCLUSIONS

Anti-livin antibodies were detected in sera from breast cancer patients by an anti-livin ELISA using full-length recombinant livin protein. Like survivin, livin may act as a major cancer antigen in breast cancer patients.

Expression and significance of new inhibitor of apoptosis protein survivin in hepatocellular carcinoma

AIM: To investigate expression and significance of inhibitor of apoptosis protein survivin in hepatocellular carcinoma (HCC).

METHODS: The expression of survivin and vascular endothelial growth factor (VEGF) was investigated in 38 cases of HCC tissues and 38 liver cirrhosis tissues by immunohistochemistry and Western blot. The relationship between the expression of survivin and clinicopathological factors of HCC was analyzed.

RESULTS: Survivin protein was detected in 23 (60.5%) of 38 HCCs and 3 (7.9%) of 38 liver cirrhosis tissues. In 23 cases of HCC which expressed survivin, the expression of VEGF was positive in 18 cases and slight positive or negative in 5 cases. While in 15 cases of HCC which did not express survivin, 12 cases did not express or slightly expressed, and 3 cases expressed VEGF. In liver cirrhosis tissues, the expression of VEGF was as follows: 24 cases were negative, 10 cases were weak positive and 4 cases were strong positive. The expression of survivin was coincident with the expression of VEGF in HCC (P < 0.01). The expression of survivin in HCC had no relationship with the patients’ age, gender, tumor size and differentiation level of HCC, while it was related to the metastasis of HCC. The protein quantitative analysis by Western blot also showed that overexpression of survivin in HCC was closely correlated to the expression of VEGF (P < 0.01). Furthermore, stronger expression of survivin and VEGF was also found in patients with metastasis rather than in those with no metastasis (P < 0.01).

CONCLUSION: Survivin plays a pivotal role in the metastasis of HCC, and it has some correlation with tumorigenesis. The expression of survivin in the primary lesion is very useful as an indicator for metastasis and prognosis of HCC. It could become a new target of gene therapy of HCC.

Survivin as prognostic factor in squamous cell carcinoma of the oral cavity

A series of 78 cases of oral squamous cell carcinoma was analysed by immunohistochemistry for expression of survivin, a recent apoptosis inhibitor. All cases were positive for survivin expression and were divided into two groups using a system of scores. Disease-specific survival curves were calculated according to Kaplan-Meier algorithm, and log rank test was used to compare survival curves. Then, Cox regression analysis was applied to determine the single contribution of covariates on survival rate. So, Cox analysis allowed us to detect the variables most associated to survival. Among the studied variables, such as grade of differentiation, tumor size, stage, recurrence of disease, lymph node presence, only stage and recurrence of disease were predictors of outcome; however, when we analyzed the survival without considering recurrence (that was the stronger predictor of death), a stepwise Cox analysis showed that Survivin, stage and grade of differentiation are significantly associated to survival, with a higher value for Survivin. These data suggest that survivin expression may identify cases of oral squamous cell carcinoma with more aggressive and invasive phenotype and, therefore, could influence the decision for the therapy at the time of diagnosis.

Survivin enhances telomerase activity via up-regulation of specificity protein 1- and c-Myc-mediated human telomerase reverse transcriptase gene transcription

Suppression of apoptosis is thought to contribute to carcinogenesis. Survivin, a member of the inhibitor-of-apoptosis family, blocks apoptotic signaling activated by various cellular stresses. Since elevated expression of survivin observed in human cancers of varied origin was associated with poor patient survival, survivin has attracted growing attention as a potential target for cancer treatment. Immortalization of cells also is required for carcinogenesis; telomere length maintenance by telomerase is required for cancer cells to proliferate indefinitely. Yet how cancer cells activate telomerase remains unclear. We therefore examined possible interrelationships between survivin expression and telomerase activity. Correlation between survivin and human telomerase reverse transcriptase (hTERT) expression was observed in colon cancer tissues, and overexpression of survivin enhanced telomerase activity by up-regulation of hTERT expression in LS180 human colon cancer cells. DNA-binding activities of specificity protein 1 (Sp1) and c-Myc to the hTERT core promoter were increased in survivin gene transfectant cells. Phosphorylation of Sp1 and c-Myc at serine and threonine residues was enhanced by survivin, while total amounts of these proteins were unchanged. Further, "knockdown" of survivin by a small inhibitory RNA decreased Sp1 and c-Myc phosphorylation. Thus survivin participates not only in inhibition of apoptosis, but also in prolonging cellular lifespan.

Cellular localisation of survivin: impact on the prognosis in colorectal cancer

PURPOSE

The present study was designed to determine whether the nuclear or cytoplasmic expression of survivin, was related to clinicopathological parameters and survival in sporadic colon carcinomas.

METHODS

Western blotting of cell fractions and immunocytochemical methodology were used in five human colon cancer cell lines. Immunohistochemical study was performed in formalin-fixed paraffin-embedded section from 46 patients with sporadic colorectal adenocarcinomas with a polyclonal antibody directed against survivin. Apoptotic index was evaluated by using the M30 antibody. Survival rates were estimated by the Kaplan-Meier method and compared using the log-rank test. Multivariate survival analysis was performed by the Cox proportional hazards model.

RESULTS

Western blotting and immunocytochemistry analyses confirmed that survivin could be detected both in the nucleus and the cytoplasm. Immunohistochemical analysis demonstrated that 39% of tumours expressed survivin in the nucleus and 41% in the cytoplasm. No relationship was observed between survivin expression and clinicopathological features. Unexpectedly, the apoptotic index appeared to be linked with high survivin nuclear expression. Overall, 3-year observed survival rate was 73% in patients with cytoplasmic survivin expression versus 48% for negative expression (P = 0.14). Survival was 72% versus 50% for positive nuclear survivin expression versus negative (P = 0.16). After adjustment for age and stage, cytoplasmic survivin expression was a significant prognostic factor. A high level of expression was associated to a better survival: RR = 0.35 [0.13-0.98], P = 0.045.

CONCLUSION

These results indicate that the analysis of the subcellular expression of survivin is a determining factor to define the prognostic value. Its evaluation, using a polyclonal antibody, might help clinicians in the stratification of patients with colorectal cancer.

No prognostic impact of survivin expression in glioblastoma

Survivin is a member of a novel protein family of inhibitors of apoptosis, and also plays a role as a potent regulator of mitosis. In semiquantitative Western blot analysis of glioblastomas, survivin expression was shown to be a prognostically significant factor. In the present study we investigated the immunohistochemical expression of survivin and its prognostic impact in a large glioblastoma series comprising 104 consecutive adult patients undergoing a first operation for glioblastoma. We analyzed survivin, Ki-67, and topoisomerase-II-alpha expression in paraffin-embedded tissue, and correlated patient age, Karnofsky performance score, vascular pattern and survivin-, Ki-67-, topoisomerase-II-alpha-, and apoptotic indices with patient outcome using univariate and multivariate survival analysis. Survivin was expressed in all glioblastoma samples, and was prominent in a fraction of nuclei of tumor cells and vascular cells. Further, survivin labeled spindle- and chromosomal material of mitotic figures. Faint cytoplasmic expression was also seen. The survivin index showed significant correlation with Ki-67 and Topo-II-alpha indices. On average, 58.85% of Ki-67 and 91.08% of survivin-expressing nuclei co-expressed Ki-67 and survivin. The survivin index did not correlate significantly with overall survival, whereas patient age, Karnofsky performance score, vascular pattern, and Ki-67 and topoisomerase-II-alpha indices were associated with patient outcome. In summary, in glioblastoma, survivin is expressed predominantly in proliferating tumor cell nuclei. In contrast to Ki-67 and topoisomerase-II-alpha, survivin expression does not influence patient outcome. So, in contrast to Ki-67, survivin does not seem to be useful as prognostic factor in the clinical setting.

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Exploiting death receptor signaling pathways for tumor therapy

Apoptosis or programmed cell death is a key regulator of physiological growth control and regulation of tissue homeostasis. Tipping the balance between cell death and proliferation in favor of cell survival may result in tumor formation. Moreover, current cancer therapies, e.g. chemotherapy, gamma-irradiation, immunotherapy or suicide gene therapy, primarily exert their antitumor effect by triggering an evolutionary conserved apoptosis program in cancer cells. For example, death receptor signaling has been implied to contribute to the efficacy of cancer therapy. Thus, failure to undergo apoptosis in response to anticancer therapy because of defects in death receptor pathways may result in resistance. Further insights into the mechanisms regulating apoptosis in response to anticancer therapy and how cancer cells evade cell death may provide novel opportunities for targeted therapeutics. Thus, agents designed to selectively activate death receptor pathways may enhance the efficacy of conventional therapies and may even overcome some forms of cancer resistance.

Apoptosis pathway-targeted drugs--from the bench to the clinic

It is an exciting time for cancer researchers in the field of apoptotic cell death. The avalanche of discoveries over the past decade or so regarding how apoptosis is regulated begins to be exploited for therapeutic benefit as the first apoptosis-targeted drugs enter early clinical trials. This chapter provides a selective review on the development of such drugs. We also outline issues regarding the regulation and design of early clinical trials of this type of molecularly targeted agent. Finally, we discuss the biomarkers and surrogate pharmacodynamic endpoint assays currently available to chart the efficacy of apoptosis-inducing anticancer therapy.

Knockdown of survivin gene expression by RNAi induces apoptosis in human hepatocellular carcinoma cell line SMMC-7721

AIM: To investigate the survivin gene expression in human hepatocellular carcinoma cell line SMMC-7721 and the effects of survivin gene RNA interference (RNAi) on cell apoptosis and biological behaviors of SMMC-7721 cells.

METHODS: Eukaryotic expression vector of survivin gene RNAi and recombinant plasmid pSuppressorNeo-survivin(pSuNeo-SVV), were constructed by ligating into the vector, pSupperssorNeo (pSuNeo) digested with restriction enzymes Xba I and Sal I and the designed double-chain RNAi primers. A cell model of SMMC-7721 after treatment with RNAi was prepared by transfecting SMMC-7721 cells with the lipofectin transfection method. Strept-avidin- biotin-complex (SABC) immunohistochemical staining and RT-PCR were used to detect survivin gene expressions in SMMC-7721 cells. Flow cytometry was used for the cell cycle analysis. Transmission electron microscopy was performed to determine whether RNAi induced cell apoptosis, and the method of measuring the cell growth curve was utilized to study the growth of SMMC-7721 cells before and after treatment with RNAi.

RESULTS: The eukaryotic expression vector of survivin gene RNAi and pSuNeo-SVV, were constructed successfully. The expression level of survivin gene in SMMC-7721 cells was observed. After the treatment of RNAi, the expression of survivin gene in SMMC-7721 cells was almost absent, apoptosis index was increased by 15.6%, and the number of cells was decreased in G2/M phase and the cell growth was inhibited.

CONCLUSION: RNAi can exert a knockdown of survivin gene expression in SMMC-7721 cells, and induce apoptosis and inhibit the growth of carcinoma cells.

Detection of autoantibodies to livin and survivin in Sera from lung cancer patients

Survivin and livin are highly expressed in cancer cells and transformed cells, but show little or no expression in normal differentiated tissues. Although human antibody responses to cancer-associated antigens have been detected, the response to livin has not yet been described in lung cancer patients. We examined prevalence of anti-livin antibodies in such patients with a specific enzyme-linked immunosorbent assay (ELISA) using recombinant protein. Using a cutoff value for positivity determined as the mean absorbance +2S.D. for healthy control samples, 19 of 37 lung cancer patients (51.3%) were positive for anti-livin antibodies. Of 31 samples from the same lung cancer patients, 18 (58.1%) were positive for anti-survivin antibodies. When sera from 31 lung cancer patients were assessed simultaneously by anti-survivin and anti-livin ELISAs. Twenty-one patients (71%) were positive for survivin, livin, or both. Intensity of anti-livin antibody responses did not correlate with intensity of anti-survivin responses. Like anti-survivin antibodies, anti-livin antibodies, thus, can be detected in many lung cancer patients. Testing for both antibodies together may prove useful in detecting lung cancer, but more extensive studies are needed to establish the clinical significance of anti-livin antibodies.

Mutations of the p53 gene and loss of heterozygosity at chromosome 17p13.1 are associated with increased survivin expression in breast cancer

Expression of survivin, a member of the inhibitor-of-apoptosis (IAP) family, is elevated in fetal tissues and in various human cancers originating in the breast, lung, prostate, colon, pancreas, and stomach. Since overexpression of the survivin gene has been linked to poor patient survival in several cancers, survivin may be an important prognostic marker. Mechanisms up-regulating survivin gene expression in cancer are poorly understood. Recently, wild-type p53 was found to repress expression of the survivin gene by binding to the survivin promoter, thereby inhibiting promoter activity. Further, loss of heterozygosity (LOH) at 17p13 distal to the p53 gene is associated with more aggressive behavior of breast cancers. We therefore tested the hypothesis that not only p53 gene mutation but also LOH at 17p13 can up-regulate survivin expression in breast cancer. Survivin mRNA expression was greater in cancers than in uninvolved tissues (p < 0.0001). Mutations of the p53 gene were detected in 5 of 25 tumors; higher survivin gene expression was evident in these. LOH at the D17S938 locus (17p13.1) was found in 10 of 25 tumors, and most of these also showed increased survivin gene expression. Thus expression of survivin may be regulated not only by p53 but additionally by a putative tumor suppressor gene located at 17p13 distal to the p53 gene.

Expression of cell cycle markers and human papillomavirus infection in oral squamous cell carcinoma: Use of fuzzy neural networks

Our aim was to evaluate in oral squamous cell carcinoma (OSCC) the relationship between some cell cycle markers and HPV infection, conditionally to age, gender and certain habits of patients, and to assess the ability of fuzzy neural networks (FNNs) in building up an adequate predictive model based on logic inference rules. Eighteen cases of OSCC were examined by immunohistochemistry for MIB-1, PCNA and survivin expression; presence of HPV DNA was investigated in exfoliated oral mucosa cells by nested PCR (nPCR, MY09-MY11/GP5-GP6), and HPV genotype was determined by direct DNA sequencing. Data were analyzed by traditional statistics (TS) and FNNs. HPV DNA was found in 9/18 OSCCs (50.0 %) without any significant higher risk of HPV infection with respect to the sociodemographic variables considered (p > 0.2), apart from tobacco smoking, reported in 44.4% of OSCC HPV-positive vs. 100% HPV-negative subjects (p = 0.029). Regarding cell cycle markers, TS and FNN revealed that survivin was expressed significantly more in HPV-negative than in HPV-positive OSCC [root mean-square error (RMSE) = 5.89 x 10(-6), % predicted 100.0]; furthermore, smoking played a protective role for survivin expression in HPV-positive cases (OR = 0.019, 95%CI 0.001-0.723, RMSE = 0.20, % of prevision 94.4). FNN, although on a small sample size, allowed us to confirm data by TS and to hypothesize a different cell cycle pattern for HPV-positive vs. HPV-negative OSCC. In the latter cases, the relevance of apoptotic vs. proliferative markers suggested that they may be related to the different supposed outcome of HPV-negative OSCC and that HPV may have a protective role in the expression level of survivin, especially in tobacco smokers.

The molecular biology of esophageal adenocarcinoma

BACKGROUND

Barrett's esophagus is an acquired metaplastic change that occurs in the distal esophagus secondary to chronic gastroesophageal reflux. This premalignant condition forms the most important risk factor for developing esophageal adenocarcinoma, which is an extremely aggressive tumor with a 5-year survival rate of less than 25%. Carcinomas that arise in the setting of Barrett's esophagus are thought to develop as part of the metaplasia-dysplasia-carcinoma sequence.

OBJECTIVE

To review the current knowledge on the genomic alterations involved in the development of Barrett's esophagus and its progression to dysplasia and/or cancer.

RESULTS

Several changes in gene structure, gene expression, and protein structure are associated with the progression of Barrett's esophagus to adenocarcinoma. Accumulation of these changes seems to be essential, rather than the exact sequence of these changes. Multiple molecular pathways are involved and interact with each other. Alterations in tumor suppressor genes, amongst which p53 and p16, are early events in the metaplasia-dysplasia-adenocarcinoma sequence, followed by loss of cell cycle checkpoints. Ongoing genomic instability leads to cumulative genetic errors and thereby the generation of multiple clones of transformed cells.

CONCLUSIONS

Within the multistep process of esophageal adenocarcinogenesis, to date no single molecular marker came forward able to predict who will and who will not develop cancer in the setting of Barrett's esophagus. Instead, panels of markers need to be developed in the future allowing to indicate disease progression. Identification of crucial molecular pathways involved in esophageal adenocarcinogenesis would ultimately improve therapy and facilitate development of new treatment strategies.

Quantitative evaluation of the apoptosis regulating genes Survivin, Bcl-2 and Bax in inflammatory and malignant pleural lesions

AIM

We aimed to identify defects in the programmed cell death pathway that can be related to pleural malignant mesothelioma (MM) unresponsiveness to chemotherapy.

MATERIALS AND METHODS

We quantified mRNA levels of the apoptosis regulating genes Survivin, member of the IAP family, Bcl-2 and Bax, members of the Bcl-2 family. We studied 22 non-neoplastic pleural samples, comprising normal and inflammatory tissue specimens, and 42 pleural MMs using real-time RT-PCR.

RESULTS

Very low mRNA levels of each apoptotic gene were detected in all normal pleural samples. All three genes displayed increased mRNA levels in inflammatory and tumor specimens. Survivin levels in pleuritis and MMs were significantly increased (333% and 908%, respectively) compared to normal counterparts (p=0.0147 and 0.00349, respectively). Bcl-2 and Bax levels were increased in inflammatory pleural samples (394%, p=0.001 and 188%, p=ns, respectively) and in MMs (94%, p=ns and 88%, p=0.0163, respectively). The Bcl-2/Bax ratio was higher in pleuritis than in MMs, compared to normal pleurae (441%, p=ns and 22%, p=ns, respectively); the difference between Bcl-2/Bax ratio in inflammatory and neoplastic pleural samples was significant (p=0.00375).

CONCLUSIONS

These results suggest that apoptotic defects in pleural MMs are linked to increased levels of Survivin, whereas variations in Bcl-2 and Bax expression appear less significant, although further studies are needed to highlight Bcl-2 family members interactions in apoptosis control. Survivin progressive accumulation from normal pleura to MM suggests this gene may be important in mesothelial cancerogenesis. Survivin overexpression may also be involved in pleural MM resistance to oncological therapies. Therefore, Survivin may represent a promising novel target for selective therapies.

Inhibitor of apoptosis proteins: translating basic knowledge into clinical practice

The inhibitor of apoptosis proteins (IAPs) are a family of antiapoptotic proteins that bind and inhibit caspases 3, 7, and/or 9, but not caspase 8. Growing evidence also indicates that IAPs also modulate cell division, cell cycle progression, and signal transduction pathways. As our basic understanding of IAPs has increased, the knowledge is being translated into clinically useful applications in the diagnosis and treatment of malignancy. For example, IAPs such as survivin are being investigated as diagnostic markers for the presence of occult malignancy. In addition, IAP overexpression is a poor prognostic marker in a variety of solid tumors and hematologic malignancies. Finally, IAPs are attractive therapeutic targets, and efforts are under way to develop antisense and chemical IAP inhibitors that may be useful for the treatment of a variety of malignancies. For all of these potential clinical applications, however, the challenge remains to incorporate these findings into actual clinical practice.

HPV DNA and survivin expression in epithelial oral carcinogenesis: a relationship?

HPV has been thought to be involved in the development of several oral diseases, such as premalignant mucosal lesions and oral carcinoma. Survivin is a recently characterized IAP protein, which is abundantly expressed in most solid and haematological malignancies, but undetectable in normal adult tissues. Aim of this study was to investigate survivin expression and HPV presence in oral premalignant lesions and oral carcinoma. 47 samples of oral tissue including 11 squamous cell carcinomas (OSCC), 16 oral leukoplakias (OL) and 20 normal oral mucosa specimens, after investigation of HPV presence by nested PCR (consensus MY/GP primers) and viral genotype identification by direct sequencing were investigated by immunohistochemistry to detect survivin expression. Survivin expression was evident in 4/7 (57.1%) HPV+ and 4/4 (100%) HPV- OSCC, 6/7 (85.7%) HPV+ and 5/9 (55.5%) HPV- OL and in 0/20 (0%) control samples. Data showed high levels of survivin expression in HPV-positive SCCs, even if mean values were lower than HPV-negative ones, which in particular showed survivin expression in 100% of cases. Conversely, survivin expression was greater in HPV+ precancerous lesions than in HPV- ones. Our findings suggest that survivin may be involved in HPV- mediated deregulation during maturation of squamous epithelium through modulation of the apoptotic processes and, conversely, HPV may have a direct or indirect effect on the regulation of the survivin expression level. In particular, the results of this study suggest distinguishing between cancerous and precancerous oral lesions with respect to survivin expression when HPV infection is present. The most unfavourable behaviour is likely to be for the HPV- OSCC.

Expression of survivin in primary and metastatic gastric cancer cells obtained by laser capture microdissection

AIM: Survivin, a recently identified member of the inhibitor of apoptosis protein family, is expressed during development and in various human cancers. However, its expression in normal tissues and clinical relevance in cancers are still debated. In the present study, we analyzed the expression of the survivin gene in human primary and metastatic gastric cancer cells as well as in paired epithelial cells from normal gastric mucosa by means of a novel laser capture microdissection (LCM) technique coupled with reverse transcription - polymerase chain reaction (RT-PCR).

METHODS: Thirty patients who had undergone gastrectomy with lymph node dissection for gastric cancer without preoperative treatments were included. Neoplastic tissue, metastatic lymph nodes, and apparently uninvolved normal tissue were collected from each patient. LCM-captured “pure” cell groups were respectively subjected to RT-PCR analysis with primers specific for the survivin gene.

RESULTS: Of the paired samples from 30 gastric cancer patients studied, 24 (80%) primary gastric cancer cell groups and 7 (23%) adjacent morphologically “normal” gastric epithelial cell groups were shown to have a detectable survivin expression. There was a statistically significant difference in suvivin expression between these two groups (P < 0.01). Meanwhile, 95% (19/20) of the metastatic gastric cancer cell groups from lymph nodes had a clear expression of the survivin gene. However, no significant correlation between survivin expression and clinicopathological features of gastric cancer was observed in the present study.

CONCLUSION: Survivin expression is present in the majority of gastric cancer cell groups obtained by LCM techniques. The high expression rate in metastatic lesions suggests a possible role of survivin in cancer invasiveness and metastasis. It may contribute to the detection of gastric cancer micrometastasis as a potential molecular marker. In addition, the high expression percentage renders survivin a potential target in the therapy for gastric cancer.

Survivin expression is an independent prognostic factor in rectal cancer patients with and without preoperative radiotherapy

PURPOSE

Survivin, as an inhibitor of apoptosis, is undetectable in normal tissues but expressed in tumors. Survivin expression in rectal cancer patients who have undergone preoperative radiotherapy (RT) alone has not been studied. We analyzed the relationships of survivin expression to RT, clinicopathologic variables, apoptosis, and p53 expression in rectal cancer patients who participated in a trial of preoperative RT.

METHODS AND MATERIALS

Survivin was immunohistochemically examined in 98 rectal tumors (74 had adjacent normal mucosa). Of 98 patients, 57 underwent surgery alone and 41 underwent RT before surgery.

RESULTS

Survivin positivity was related to worse survival, independent of Dukes' stage, local and distant recurrence, differentiation, gender, age, apoptosis, and p53 expression (p = 0.02). Survivin was not associated with survival in the patients without (p = 0.08) or with (p = 0.19) RT. After RT, survivin tended to be increased in adjacent normal mucosa (p = 0.057) but not in tumors (p = 0.71).

CONCLUSION

Survivin was independently related to survival in rectal cancer patients who participated in a trial of preoperative RT, but not in either treatment group (surgery alone or surgery plus RT). Whether the effect of survivin on tumors is associated with RT and further related to patient survival needs to be investigated in a larger number of patients.

Expression of survivin and its significance in colorectal cancer

AIM: To study the expression of survivin,a novel member of inhibitors of apoptosis protein (IAP) and its significance in colorectal carcinoma.

METHODS: Survivin mRNA expression was evaluated by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in 52 colorectal carcinoma samples and 48 adjacent normal colorectal tissue samples. PCR product was sequenced to verify the desired result. Expressions of survivin protein, proliferating cell nuclear antigen labelling index (PI) and apoptotic index (AI) were detected immunohistochemically in 52 human colorectal carcinomas.

RESULTS: The expression of survivin mRNA was detected in a significantly greater proportion of colorectal carcinoma samples than in adjacent normal colorectal tissues (67.3% vs 25%; P < 0.01). There was no relationship between survivin mRNA expression in colorectal carcinomas and sex, tumor size, histological types, lymphnode metastasis, distant metastasis and Dukes’ stage. The PCR product shared 99% of homology with human counterparts. Survivin expression was observed immunohistochemically in 27 of 52 cases of colorectal carcinoma (51.9%). The AI was significently lower in survivin positive group than in survivin negative group (0.67% ± 0.18% vs 1.14% ± 0.42%; P < 0.001), while the PI was greater in survivin positive group than in survivin negative group (51% ± 22% vs 27% ± 18%, P < 0.001).

CONCLUSION: Survivin is a special tumor marker independent of histopathological characteristics. It may play an important role during human colorectal tumorigenesis by inhibiting apoptosis and accelerating proliferative activity of colorectal tumor cells.

Cloning and expression of human anti-apoptosis gene survivin in Escherchia coli

AIM: To clone and express human antiapoptosis gene-survivin (SVV) in Escherchia coli.

METHODS: The SVV cDNA was obtained by using RT-PCR method with total RNA extracted from the human gastric cancer cell line, SGC7901. Then it was cloned into the pGEM-T easy vector, and subcloned into expression vector pRSET. After proved to be correct by sequencing, recombinant expression plasmid pRSET-SVV was transformed into E.coli BL21 (DE3). The fusion protein was produced by IPTG induction.

RESULTS: The SVV cDNA was obtained and its sequence was proved to be correct by sequencing identification, a new anticipated Mr 19 500-protein band appeared on SDS-PAGE gel induced by IPTG.

CONCLUSION: Human SVV cDNA is cloned and highly expressed in E.coli. This is important for studying its functions in the carcinogenesis and progress of neoplasm.

Subcellular expression of c-IAP1 and c-IAP2 in colorectal cancers: relationships with clinicopathological features and prognosis

The Inhibitor of Apoptosis Protein (IAP) family includes several critical cell death inhibitors, the expression of which could be involved in colorectal carcinogenesis. Among them, c-IAP1 and c-IAP2 expression has never been investigated in colorectal cancer. The present study was designed to determine whether expression of both IAPs was related to pathological parameters and survival in sporadic colon carcinomas. Analysis of five human colon cancer cell lines by both western blotting of cell fractions and immunocytochemistry showed that the two IAPs could be expressed both in the nucleus and in the cytoplasm. Immunohistochemical analysis of a series of 46 sporadic colorectal adenocarcinomas demonstrated that c-IAP1 expression was more frequent in the nucleus (85%), and that c-IAP2 was more often expressed in the cytoplasm (82%). A significant association was identified between a strong lymphoid infiltrate in the stroma and the nuclear expression of c-IAP2 (p = 0.02). No other relationship was observed between IAP expression and pathological features. After adjusting by age and stage, the relative risk of death was lower for cytoplasmic c-IAP1, cytoplasmic c-IAP2, and nuclear c-IAP2 expression. It was higher for nuclear c-IAP1 expression. These associations were not statistically significant, but this work underlines the importance of taking into account the subcellular location of the IAP family members in the evaluation of their prognostic significance.

Survivin expression predicts poorer prognosis in anaplastic large-cell lymphoma

PURPOSE

Survivin, a member of the inhibitor of apoptosis (IAP) family, is not detected in normal adult tissues but is overexpressed in various cancers, including some types of lymphoma. The frequency and prognostic significance of survivin expression in anaplastic large-cell lymphoma (ALCL) is unknown.

MATERIALS AND METHODS

We assessed for survivin expression in 62 ALCL tumors (30 anaplastic lymphoma kinase [ALK]-positive and 32 ALK-negative) obtained before doxorubicin-based chemotherapy. Given that survivin is a target of the STAT3 signaling pathway and STAT3 is activated in ALCL, survivin expression was also correlated with STAT3 activation.

RESULTS

Survivin was expressed in 34 tumors (55%) and did not correlate with ALK. A significant association between survivin expression and STAT3 activation was observed (P =.007, Fisher's exact test). For the ALK-positive group, the 5-year failure-free survival (FFS) was 34% for patients with survivin-positive ALCL compared with 100% for patients with survivin-negative ALCL (P =.009, log-rank test). For the ALK-negative group, the 5-year FFS was 46% for patients with survivin-positive tumors compared with 89% for patients with survivin-negative tumors (P =.03, log-rank test). Overall survival was similarly worse for patients with survivin-positive tumors in both the ALK-positive and ALK-negative groups. Furthermore, multivariate analysis confirmed the independent prognostic value of survivin expression, along with age older than 60 years and Ann Arbor stage III or IV.

CONCLUSION

Survivin is expressed in approximately half of ALCL tumors and independently predicts unfavorable clinical outcome. Modulation of survivin expression or function may provide a novel target for experimental therapy in patients with ALCL.

Expression of the survivin gene in prostate cancer: correlation with clinicopathological characteristics, proliferative activity and apoptosis

PURPOSE

Although survivin expression has been reported in prostate cancer, the clinical significance of survivin expression remains unclear. To clarify the clinical significance of survivin in prostate cancer we examined survivin mRNA levels in prostate cancer tissues, and correlated these levels with parameters including the clinicopathological characteristics of patients and proliferation and apoptosis levels within prostate cancer tissues.

MATERIALS AND METHODS

Cancer and matched control tissues were obtained from the prostates of 150 patients who were treated with radical prostatectomy between July 1998 and December 2002. Of the 150 samples, RNA could be extracted and pathological confirmation obtained from 82 prostate cancer and 80 normal prostate samples. Polymerase chain reaction studies were performed using primers for the survivin gene with the G3PDH gene serving as control. Preoperative prostate specific antigen doubling time (PSA-DT) could be calculated for 50 patients by linear regression analysis. Immunohistochemical staining was used to study expression of proliferating cell nuclear antigen as an index of proliferative activity and single stranded DNA as an index of apoptosis.

RESULTS

Of 82 prostate cancer samples 68 (82.9%) and 47 (58.8%) of 80 control samples exhibited detectable levels of survivin mRNA. In the 65 cases in which RNA could be extracted from prostate cancer and matched control samples, the mean level of survivin expression +/- SE in prostate cancer was significantly higher than that found in control tissues (0.079 +/- 0.017 vs 0.025 +/- 0.005, p = 0.003). The survivin expression in cancers with a short PSA-DT (less than 2 years) was significantly higher than those with a moderate PSA-DT (2 to 4 years, p <0.05) or long PSA-DT (greater than 4 years, p <0.05). In the 82 cases with prostate cancer, survivin expression was significantly higher in cancers with a high pathological T stage (p <0.05), positive lymph node metastasis (p = 0.002), positive vessel invasion (p = 0.03), positive surgical margin (p = 0.02) and high Gleason score (p <0.05). A positive correlation was present between survivin expression and proliferative activity (p = 0.005). A nonsignificant inverse association was found between survivin expression and apoptosis of prostate cancer cells (p = 0.06).

CONCLUSIONS

These results suggest that the degree of survivin expression is related to the progression and aggressiveness of prostate cancer.

Inhibition of survivin expression suppresses the growth of aggressive non-Hodgkin's lymphoma

Survivin is a member of the inhibitor of apoptosis protein (IAP) family and functions both as an apoptosis inhibitor and a regulator of cell division. Survivin overexpression is common in many human tumors and correlates with survival in large cell non-Hodgkin's lymphoma. To evaluate this molecule as a potential therapeutic target in large-cell lymphoma, we evaluated the effect of survivin inhibition both in vitro and in vivo. Using an antisense oligonucleotide (ASO) approach, cell growth was significantly inhibited in the DoHH2, RL and HT lymphoma cell lines. In a lymphoma xenograft model, the development of tumors as well as the growth of established tumors was inhibited in the survivin ASO-treated mice compared to controls. To assess the efficacy of the survivin ASO in combination with other biological agents, we combined the survivin ASO with an anti-CD20 monoclonal antibody, rituximab. The effect of survivin ASO and rituximab in combination was additive in vitro. In vivo, however, suppression of tumor growth with the combination was not significantly superior to controls. We conclude that inhibition of survivin expression is an attractive therapeutic strategy in aggressive non-Hodgkin's lymphomas, and that combining survivin ASO with rituximab may enhance the efficacy of this approach.

Relationship between expression of survivin gene and proliferation of hepatocytes in liver cirrhosis and hepatocellular carcinoma

AIM: To evaluate the usefulness of detection of cell proliferation and survivin gene in choosing liver cirrhosis patients with extremely dangerous for HCC development.

METHODS: Total RNA was extracted from fresh specimens of HCC and liver cirrhosis. Survivin mRNA amplification was performed by reverse transcription polymerase chain reaction (RT-PCR). Immunostaining for proliferating cell nuclear antigen (PCNA) was employed to assess liver cell proliferative activity in formalin-fixed, paraffin-embedded liver specimens. PCNA immunostaining in liver cells of HCC and cirrhosis fresh and archive specimens was performed with monoclonal antibodies directed against CD10. Five liver specimens removed from patients with hemangioma were taken as controls. The PCNA labeling index was determined by positive cells in each microscopic field (200×) obtained from mean value of positive cells in ten different fields.

RESULTS: RT-PCR was performed in 17 HCC and 21 liver cirrhosis specimens, 11 HCC specimens showed 344 bps molecular survivin DNA band in 1% agarose electrophoresis, but none of liver cirrhosis specimens showed positive band. The survivin positive rate in HCC specimens was 64.7% (11/17). The median PCNA labeling index of 11 survivin positive HCC specimens was 6.8 (from 0.5 to 40), which was significantly higher than that of 6 survivin negative HCC specimens (2.15), while that of 21 LC and 5 normal liver specimens were 2.47 and 1.56 respectively. By using a cutoff of PCNA labeling index (3.12) obtained by two times of the index value in normal liver specimens, six specimens of 30 liver cirrhosis patients with mean PCNA labeling index 5.05±2.61 were considered high proliferative activity.

CONCLUSION: Expression of survivin is detected in HCC tissues but not in liver cirrhosis tissues, indicating that the gene expression may occur at the late phase of HCC transformation. The PCNA detection can be a good mean in screening the high-risk people with elevated possiblity of HCC development among liver cirrhosis patients.