Survivin, bcl-2, bax, and bcl-X gene expression in sentinel lymph nodes from melanoma patients

New insights into the roles of antiapoptotic members of the Bcl-2 family in melanoma progression and therapy

Prosurvival and antiapoptotic B cell lymphoma-2 (Bcl-2) family proteins are often overexpressed in cutaneous melanoma, one of the most aggressive types of human cancer. They are also implicated in resistance to therapy and participate in melanoma progression by regulating various processes, including cell proliferation, migration, invasion, and crosstalk with the tumor microenvironment. In this review, we summarize recent findings related to prosurvival members of the Bcl-2 family beyond their canonical functions in the apoptotic pathway, mainly focusing on their potential roles as diagnostic and prognostic biomarkers in cutaneous melanoma. We also provide an overview of different approaches used to inhibit Bcl-2 proteins in preclinical and clinical studies, which are mainly based on the inhibition of protein expression or the disruption of their antiapoptotic functions.

In vivo the antioxidative extract of Averrhoa carambola Linn. leaves induced apoptosis in Ehrilch ascites carcinoma by modulating p53 expression

This study was designed to evaluate the antioxidant activity of methanol extract of Averrhoa carambolla Linn. leaves (MELA) using DPPH· and ABTS·+ free radical scavenging assays whereas its antineoplastic effect against Ehrlich ascites carcinoma (EAC) was assed using viable cell count, life span, body weight gain and hematological parameters of experimental mice. Results showed that rich phenolic and flavonoid content of MELA had moderate dose dependent free radical scavenging activity (IC50: 62.0 μg/mL for DPPH· and 6.0 μg/mL for ABTS·+). In vivo antineoplastic assay, MELA significantly (P < 0.05) decreased viable cells and body weight gain, increased the survival time and restored altered hematological profiles of cancer cell bearing mice. Fluorescence microscopic view of EAC cells derived from MELA-treated group showed apoptotic characteristics and this observation was also supported by overexpression of pro-apoptotic genes coding p53 and Bax proteins in treated cancer cells. The anti-apoptotic genes coding Bcl-2 protein was also absent in treated EAC cells as compared with the control. Moreover, phytochemical profiles of MELA as identified by GC/MS analysis are also consistent with its activities.

Inhibition of MERTK Promotes Suppression of Tumor Growth in BRAF Mutant and BRAF Wild-Type Melanoma

Molecularly-targeted agents have improved outcomes for a subset of patients with BRAF-mutated melanoma, but treatment of resistant and BRAF wild-type tumors remains a challenge. The MERTK receptor tyrosine kinase is aberrantly expressed in melanoma and can contribute to oncogenic phenotypes. Here we report the effect of treatment with a MERTK-selective small molecule inhibitor, UNC2025, in preclinical models of melanoma. In melanoma cell lines, treatment with UNC2025 potently inhibited phosphorylation of MERTK and downstream signaling, induced cell death, and decreased colony formation. In patient-derived melanoma xenograft models, treatment with UNC2025 blocked or significantly reduced tumor growth. Importantly, UNC2025 had similar biochemical and functional effects in both BRAF-mutated and BRAF wild-type models and irrespective of NRAS mutational status, implicating MERTK inhibition as a potential therapeutic strategy in tumors that are not amenable to BRAF-targeting and for which there are limited treatment options. In BRAF-mutated cell lines, combined treatment with UNC2025 and the BRAF inhibitor vemurafenib provided effective inhibition of oncogenic signaling through ERK, AKT, and STAT6, increased induction of cell death, and decreased colony-forming potential. Similarly, in NRAS-mutated cell lines, addition of UNC2025 to cobimetinib therapy increased cell death and decreased colony-forming potential. In a BRAF-mutated patient-derived xenograft, treatment with combined UNC2025 and vemurafenib was well-tolerated and significantly decreased tumor growth compared with vemurafenib alone. These data support the use of UNC2025 for treatment of melanoma, irrespective of BRAF or NRAS mutational status, and suggest a role for MERTK and targeted combination therapy in BRAF and NRAS-mutated melanoma.

Study of a common azo food dye in mice model: Toxicity reports and its relation to carcinogenicity

This study was conducted to evaluate the toxic effects of an azo dye carmoisine widely used in foods and to investigate its relation to carcinogenicity. Carmoisine administered into mice orally in four different doses as control, low, medium, and high equivalent to 0, 4, 200, and 400 mg/kg bw, respectively, for 120 days. The key toxicological endpoint was observed including animal body weight, organ weights, hematology, biochemistry, and molecular biology assessment. The body weights of medium- and high-dose carmoisine-treated mice group were significantly decreased as compared to the control mice group. Platelet, white blood cell and monocyte counts of treated group were considerably higher, while Hb and red blood cell counts were drastically lower than the control group. The biochemical parameters such as serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, globulin, urea, and creatinine level were significantly increased, while serum cholesterol level was decreased after treatment as compared to the control. RT-PCR results showed that expression of Bcl-x and PARP gene was intensively increased, whereas expression of p53 gene was decreased in the mouse liver tissues treated with carmoisine. This study revealed that high-dose (400 mg/kg bw) treatment of carmoisine was attributable to renal failure and hepatotoxicity. It also would be suspected as a culprit for liver oncogenesis.

Selective in vitro anti-melanoma activity of ursolic and oleanolic acids

Products of natural origin have become important agents in the treatment of cancer, and the active principles of natural sources could be used in combination with chemotherapeutic agents to increase their effects and to minimize their toxicity. Oleanolic (OA) and ursolic (UA) acids are intensely studied for their promising anticancer potential. The aim of this study was focused on the in vitro toxicological effects induced by UA and OA human mesenchymal stem cells and on melanoma, one of the most frequent cancers whose incidence is increasing every year. The two compounds were tested for their cytotoxic, cell cycle arrest and pro-apoptotic effects on melanoma cells (A375 and B164A5) and mesenchymal stem cells. UA exerted a cytotoxic effect in a dose-dependent manner on melanoma cells, while OA's activity has been shown to be low or moderate. Both compounds produced alterations of the cell cycle, arresting cells in the G0/G1 phase. Furthermore, UA induced significant apoptosis through the bcl-2 genes family pathway, with the decrease of the bcl-2 gene expression. The two compounds exerted selective effects on melanoma cells with no effects on human mesenchymal stem cells. The presented results reveal the anticancer potential of UA on melanoma cells, with no detectable toxicity on the mesenchymal stem cells.

Morbidity of Selective Lymph Node Biopsy for Melanoma: Meta-Analysis of Complications

Background and Aim

Intraoperative lymphatic mapping and selective lymph node biopsy is accepted worldwide as the standard procedure for staging regional lymph nodes of 1–4 mm thick melanomas, as well as for other neoplasms. Although it is often stated that selective lymph node biopsy is a minimally invasive procedure associated with few complications, few data exist concerning the morbidity associated with the procedure. The present analysis was performed to evaluate the morbidity associated with selective lymph node biopsy in a long-term follow-up.

Materials and Methods

The study provides a review of 437 selective lymph node biopsies on 269 patients, operated on between the 1994 and the 2009, for the lymph node biopsy of head and neck, groin, axilla, upper and lower limbs and nodal basins. Patients’ history and follow-up were reviewed for 2 weeks after surgery, every 3 months for the first 2 years, every 4 months during the third year, and every 6 months subsequently, and postoperative morbidity was evaluated.

Results

After sentinel node biopsy, 14 patients developed one of the following complications: hematoma, 1 case (0.30%); lymphedema, 1 case (0.30%); seroma, 2 cases (0.61%); wound infection, 6 cases (1.83%); keloid scar, 2 cases (0.61%); and postoperative pain, 2 cases (0.61%). The total complication rate was 4.26%.

Conclusions

Selective lymph node biopsy for melanoma, as for other tumors, in respect to radical lymphadenectomy, is not a complications-free procedure but is usually not severe.

The HGF/SF Mouse Model of UV-Induced Melanoma as an In Vivo Sensor for Metastasis-Regulating Gene

Cutaneous malignant melanoma is an aggressive and potentially lethal form of skin cancer, particularly in its advanced and therapy-resistant stages, and the need for novel therapeutics and prognostic tools is acute. Incidence of melanoma has steadily increased over the past few decades, with exposure to the genome-damaging effects of ultraviolet radiation (UVR) well-recognized as a primary cause. A number of genetically-engineered mouse models (GEMMs) have been created that exhibit high incidence of spontaneous and induced forms of melanoma, and a select subset recapitulates its progression to aggressive and metastatic forms. These GEMMs hold considerable promise for providing insights into advanced stages of melanoma, such as potential therapeutic targets and prognostic markers, and as in vivo systems for testing of novel therapies. In this review, we summarize how the HGF/SF transgenic mouse has been used to reveal metastasis-regulating activity of four different genes (CDK4^R24C, survivin and NME1/NME2) in the context of UV-induced melanoma. We also discuss how these models can potentially yield new strategies for clinical management of melanoma in its most aggressive forms.

Correlation of survivin and B-cell lymphoma 2 expression with pathological malignancy and anti-apoptotic properties of glial cell tumors

Apoptosis, whose mechanism remains unclear, is regulated by multiple factors. B-cell lymphoma 2 (Bcl-2) is a well-known anti-apoptotic mediator. Survivin is also a recently recognized novel family inhibitor of apoptosis protein, which inhibits apoptosis via a pathway distinct from Bcl-2 family members. Survivin and Bcl-2 are expressed in various types of human cancer. In the present study, survivin and Bcl-2 expression were characterized in glial cell tumors, and the correlation with pathological malignancy and anti-apoptotic properties were investigated. Fifty-eight patients who had undergone surgical resection for glial cell tumors were evaluated. The pathological types of glial cell tumors were categorized according to the World Health Organization classification. Survivin and Bcl-2 expression levels were investigated by western blot analysis, and apoptosis was detected by DNA fragmentation analysis. The anti-apoptotic rate of glial cell tumors was calculated in tumor samples according to the expression of survivin and Bcl-2 or co-expression. Survivin was characterized in 60.3%, and Bcl-2 was expressed in 43.1% of glioma samples. Co-expression of survivin and Bcl-2 was observed in 25.9% of the tumor specimens. Survivin expression in astrocytic tumors was identified to be significantly associated with the pathological grade (P<0.05); however, Bcl-2 was not (P>0.05). Anti-apoptotic rate of glial cell tumors were detected in 91.4, 92.0 and 100% of patients exhibiting survivin, Bcl-2 or co-expression, respectively. However, the difference in anti-apoptotic frequency between the three groups was not identified to be statistically significant (P>0.05). The present study suggests that survivin expression is correlated with pathological grades of gliomas. In addition, the expression of survivin or Bcl-2 exerts potent anti-apoptotic properties in gliomas. Thus, survivin or Bcl-2 may serve as potential targets for inducing the apoptosis of gliomas.

Gene expression profiling of anti-CTLA4-treated metastatic melanoma in patients with treatment-induced autoimmunity

Ipilimumab (IPI) is a monoclonal antibody that targets the inhibitory CTLA4 receptor of T cells, enhancing T-cell-driven antitumor responses. IPI therapy in metastatic melanoma results in significant improvement in disease-free and overall survival, although after initial responses disease progression generally ensues. Identification of specific responses in tissue where melanoma tumor cells are subjected to IPI-driven immune attack may reveal mechanisms of treatment efficacy or resistance, permitting refinement of targeted therapeutic approaches. We used NanoString digital barcoding chemistry to identify changes in the transcriptome of metastatic melanoma cells before and after IPI treatment using two comprehensive panels containing a total of 1330 unique genes. Only patients who developed autoimmune disorders following treatment, signifying a robust immune response, were included. Despite evidence of an enhanced immune response, most patients eventually exhibited disease progression. Overall, data from five pre-IPI tumors and four post-IPI tumor samples (from three patients) permitted identification of several candidate genes that showed increased expression based on normalized counts after therapy. These included TTK (~3.1-fold, P=1.18e-4), which encodes a dual-specificity protein tyrosine kinase, a known cell cycle regulator, and BIRC5 (~3.0-fold, P=9.36e-4), which encodes the antiapoptotic protein survivin. Both TTK (MPS1) and survivin are targetable proteins against which a number of pharmacologic agents have been developed. CDK1, which encodes a protein tyrosine kinase known to phosphorylate survivin, was also upregulated (~3.2-fold, P=2.80-3). Tumor cell expression of TTK and survivin proteins was confirmed using immunohistochemistry in an expanded patient cohort. Differences in gene expression for several commonly encountered immune antigens, such as CD3, CD4, CD8, and CTLA4, were not statistically significant, likely reflecting the long length of time (average 323 days) between the last IPI dose and post-treatment biopsies. Although our sample size is limited, these results for the first time identify targetable genes that are significantly altered by interaction between a highly activated, IPI-treated immune system and melanoma cells.

Dehydroleucodine inhibits tumor growth in a preclinical melanoma model by inducing cell cycle arrest, senescence and apoptosis

Malignant melanoma represents the fastest growing public health risk of all cancer types worldwide. Several strategies and anti-cancer drugs have been used in an effort to improve treatments, but the development of resistance to anti-neoplastic drugs remains the major cause of chemotherapy failure in melanomas. Previously, we showed that the sesquiterpene lactone, dehydroleucodine (DhL), promotes the accumulation of DNA damage markers, such as H2AX and 53BP1, in human tumor cells. Also DhL was shown to trigger either cell senescence or apoptosis in a concentration-dependent manner in HeLa and MCF7 cells. Here, we evaluated the effects of DhL on B16F0 mouse melanoma cells in vitro and in a pre-clinical melanoma model. DhL inhibited the proliferation of B16F0 cells by inducing senescence or apoptosis in a concentration-dependent manner. Also, DhL reduced the expression of the cell cycle proteins cyclin D1 and B1 and the inhibitor of apoptosis protein, survivin. In melanomas generated by subcutaneous injection of B16F0 cells into C57/BL6 mice, the treatment with 20 mg DhL /Kg/day in preventive, simultaneous and therapeutic protocols reduced tumor volumes by 70%, 60% and 50%, respectively. DhL treatments reduced the number of proliferating, while increasing the number of senescent and apoptotic tumor cells. To estimate the long-term effects of DhL, a mathematical model was applied to fit experimental data. Extrapolation beyond experimental time points revealed that DhL administration following preventive and therapeutic protocols is predicted to be more effective than simultaneous treatments with DhL in restricting tumor growth.

The effects of human recombinant granulocyte-colony stimulating factor treatment during in vitro maturation of porcine oocyte on subsequent embryonic development

Granulocyte colony-stimulating factor (G-CSF) is required for proliferation, differentiation, and survival of cells. It is also a biomarker of human oocyte developmental competence for embryo implantation. In humans, the G-CSF concentration peaks during the ovulatory phase of the ovarian cycle. In this study, the expressions of G-CSF and its receptor were analyzed by polymerase chain reaction in granulosa cells (GCs), CL, cumulus cells (CCs), and oocytes. Cumulus-oocyte complexes were aspirated from antral follicles of 1 to 3 mm (small follicles) and 4 to 6 mm (medium follicles). Cumulus-oocyte complexes from two kinds of follicles were matured in protein-free maturation medium supplemented with various concentrations of G-CSF (0, 10, and 100 ng/mL). By real-time polymerase chain reaction, the expressions of G-CSF and its receptor were detected in GCs, CL, CCs, and oocytes. Interestingly, the G-CSF transcript levels were significantly lower in oocytes than in the other cell types, whereas the G-CSF receptor transcript levels in oocytes were similar to those in GCs. After 44 hours of IVM, no differences in the rate of nuclear maturation were detected; however, the intracellular reactive oxygen species levels in oocytes from both groups of follicles matured with 10 ng/mL of human recombinant G-CSF (hrG-CSF) groups were significantly lower (P < 0.05). After parthenogenetic activation, the cleavage rates were significantly (P < 0.05) higher in 100 ng/mL hrG-CSF-treated small (63.3%) follicles than in 0, 10 ng/mL hrG-CSF-treated small (38.6% and 49.0%, respectively) follicles and 0 ng/mL hrG-CSF-treated medium (52.1%) follicles, and the cleavage rates were significantly (P < 0.05) higher in 10 ng/mL hrG-CSF-treated medium (76.3%) follicles than in all other groups. The blastocyst formation rates were significantly (P < 0.05) higher in 100 ng/mL hrG-CSF-treated small (31.2%) follicles than in 0 and 10 ng/mL hrG-CSF small (10.4% and 15.6%, respectively) follicles, and the 10 ng/mL hrG-CSF medium (45.7%) follicle was significantly (P < 0.05) higher than in all other groups. The total cell number in blastocysts from the 10 ng/mL hrG-CSF medium (106.5) follicles was significantly (P < 0.05) increased compared to 0, 10, 100 ng/mL hrG-CSF small (55.0, 73.7 and 59.5, respectively) follicles and 0, 100 ng/mL hrG-CSF-treated medium (82.5 and 93.5, respectively) follicles. After IVF, the blastocysts stage was significantly (P < 0.05) increased in 10 ng/mL hrG-CSF-treated medium (36.4%) follicles. Fertilization efficiency was significantly high in 100 ng/mL of small (29.1%) and 10 ng/mL of medium (44.0%) follicles. We also examined the Bcl2 and ERK2 transcript levels and found that they were significantly higher in the small and medium follicle treatment groups. In conclusion, these results indicate that hrG-CSF improve the viability of porcine embryos.

A phase 2, multicenter, open-label study of sepantronium bromide (YM155) plus docetaxel in patients with stage III (unresectable) or stage IV melanoma

Survivin is a microtubule-associated protein believed to be involved in preserving cell viability and regulating tumor cell mitosis, and it is overexpressed in many primary tumor types, including melanoma. YM155 is a first-in-class survivin suppressant. The purpose of this Phase 2 study was to evaluate the 6-month progression-free survival (PFS) rate in patients with unresectable Stage III or IV melanoma receiving a combination of YM155 plus docetaxel. The study had two parts: Part 1 established the dose of docetaxel that was tolerable in combination with YM155, and Part 2 evaluated the tolerable docetaxel dose (75 mg/m²) in combination with YM155 (5 mg/m² per day continuous infusion over 168 h every 3 weeks). The primary endpoint was 6-month PFS rate. Secondary endpoints were objective response rate (ORR), 1-year overall survival (OS) rate, time from first response to progression, clinical benefit rate (CBR), and safety. Sixty-four patients with metastatic melanoma were treated with docetaxel and YM155. Eight patients received an initial docetaxel dose of 100 mg/m² and 56 patients received 75 mg/m² of docetaxel. Six-month PFS rate per Independent Review Committee (IRC) was 34.8% (n = 64; 95% CI, 21.3–48.6%), and per Investigator was 31.3% (n = 64; 95% CI, 19.5–43.9%). The best ORR (complete response [CR] + partial response [PR]) per IRC was 12.5% (8/64). The stable disease (SD) rate was 51.6% (33/64), leading to a CBR (CR + PR + SD) of 64.1% (41/64). Estimated probability of 1-year survival was 56.3%. YM155 is a novel agent showing modest activity when combined with docetaxel for treating patients with melanoma. YM155 was generally well tolerated, but the predetermined primary efficacy endpoint (i.e., 6-month PFS rate ≥20%) was not achieved.

Clinical profiling of BCL-2 family members in the setting of BRAF inhibition offers a rationale for targeting de novo resistance using BH3 mimetics

While response rates to BRAF inhibitiors (BRAFi) are high, disease progression emerges quickly. One strategy to delay the onset of resistance is to target anti-apoptotic proteins such as BCL-2, known to be associated with a poor prognosis. We analyzed BCL-2 family member expression levels of 34 samples from 17 patients collected before and 10 to 14 days after treatment initiation with either vemurafenib or dabrafenib/trametinib combination. The observed changes in mRNA and protein levels with BRAFi treatment led us to hypothesize that combining BRAFi with a BCL-2 inhibitor (the BH3-mimetic navitoclax) would improve outcome. We tested this hypothesis in cell lines and in mice. Pretreatment mRNA levels of BCL-2 negatively correlated with maximal tumor regression. Early increases in mRNA levels were seen in BIM, BCL-XL, BID and BCL2-W, as were decreases in MCL-1 and BCL2A. No significant changes were observed with BCL-2. Using reverse phase protein array (RPPA), significant increases in protein levels were found in BIM and BID. No changes in mRNA or protein correlated with response. Concurrent BRAF (PLX4720) and BCL2 (navitoclax) inhibition synergistically reduced viability in BRAF mutant cell lines and correlated with down-modulation of MCL-1 and BIM induction after PLX4720 treatment. In xenograft models, navitoclax enhanced the efficacy of PLX4720. The combination of a selective BRAF inhibitor with a BH3-mimetic promises to be an important therapeutic strategy capable of enhancing the clinical efficacy of BRAF inhibition in many patients that might otherwise succumb quickly to de novo resistance. Trial registrations: ClinicalTrials.gov NCT01006980; ClinicalTrials.gov NCT01107418; ClinicalTrials.gov NCT01264380; ClinicalTrials.gov NCT01248936; ClinicalTrials.gov NCT00949702; ClinicalTrials.gov NCT01072175.

Survivin beyond physiology: orchestration of multistep carcinogenesis and therapeutic potentials

Survivin, a member of the inhibitor of apoptosis protein family, has been associated with protection from cell apoptosis and regulation of mitosis. Survivin exhibits low to undetectable expression in most finally differentiated adult tissues but is abundantly over-expressed in almost all cancers. The aberrant high expression of survivin in cancers is associated with advanced disease, increased rate of tumor recurrence, abbreviated overall survival and resistance to chemo- and radio- therapy. Survivin touches nearly every aspect of cancer and is involved in the initiation, maintenance and development of tumor. Therefore, its significance in cancer dictates the pursuit for anti-survivin cancer therapies.

Pea lectin inhibits growth of Ehrlich ascites carcinoma cells by inducing apoptosis and G2/M cell cycle arrest in vivo in mice

Pea (Pisum sativum L.) lectin is known to have interesting pharmacological activities and of great interest on biomedical research. In the current research pea lectin was purified followed by ion exchange chromatography on DEAE column and affinity chromatography on glucose-sepharose column. The lectin shown 11.7-84% inhibitory effect against Ehrlich ascites carcinoma (EAC) cells at the concentration range of 8-120 μg/ml in RPMI 1640 medium as determined by MTT assay. Pea lectin was also shown 63% and 44% growth inhibition against EAC cells in vivo in mice when administered 2.8 mg/kg/day and 1.4 mg/kg/day (i.p.) respectively for five consequent days. When Pea lectin injected into the EAC bearing mice for 10 days its significantly increased the hemoglobin and RBC with the decreased of WBC levels toward the normal. Apoptotic cell morphological change of the treated EAC cells of mice was determined by fluorescence and optical microscope. Interestingly, cell growth inhibition of the lectin was significantly reduced in the presence of caspase inhibitors. Treatment with the lectin caused the cell cycle arrest at G2/M phase of EAC cells which was determined by flow cytometry. The expression of apoptosis-related genes, Bcl-2, Bcl-X and Bax was evaluated by reverse transcriptase polymerase chain reaction (RT-PCR). Intensive increase of Bax gene expression and totally despaired of Bcl-2 and Bcl-X gene expression were observed in the cells treated with Pea lectin for five consecutive days.

Sticky siRNAs targeting survivin and cyclin B1 exert an antitumoral effect on melanoma subcutaneous xenografts and lung metastases

Background

Melanoma represents one of the most aggressive and therapeutically challenging malignancies as it often gives rise to metastases and develops resistance to classical chemotherapeutic agents. Although diverse therapies have been generated, no major improvement of the patient prognosis has been noticed. One promising alternative to the conventional therapeutic approaches currently available is the inactivation of proteins essential for survival and/or progression of melanomas by means of RNA interference. Survivin and cyclin B1, both involved in cell survival and proliferation and frequently deregulated in human cancers, are good candidate target genes for siRNA mediated therapeutics.

Methods

We used our newly developed sticky siRNA-based technology delivered with linear polyethyleneimine (PEI) to inhibit the expression of survivin and cyclin B1 both in vitro and in vivo, and addressed the effect of this inhibition on B16-F10 murine melanoma tumor development.

Results

We confirm that survivin and cyclin B1 downregulation through a RNA interference mechanism induces a blockage of the cell cycle as well as impaired proliferation of B16-F10 cells in vitro. Most importantly, PEI-mediated systemic delivery of sticky siRNAs against survivin and cyclin B1 efficiently blocks growth of established subcutaneaous B16-F10 tumors as well as formation and dissemination of melanoma lung metastases. In addition, we highlight that inhibition of survivin expression increases the effect of doxorubicin on lung B16-F10 metastasis growth inhibition.

Conclusion

PEI-mediated delivery of sticky siRNAs targeting genes involved in tumor progression such as survivin and cyclin B1, either alone or in combination with chemotherapeutic drugs, represents a promising strategy for melanoma treatment.

Survivin promotion of melanoma metastasis requires upregulation of α5 integrin

Survivin is an apoptotic and mitotic regulator that is overexpressed in melanoma and a poor prognostic marker in patients with metastatic disease. We recently showed that Survivin enhances melanoma cell motility through Akt-dependent upregulation of α5 integrin. However, the functional role of Survivin in melanoma metastasis is not clearly understood. We found that overexpression of Survivin in LOX and YUSAC2 human melanoma cells increased colony formation in soft agar, and this effect was abrogated by knockdown of α5 integrin by RNA interference. We employed melanoma cell xenografts to determine the in vivo effect of Survivin overexpression on melanoma metastasis. Although Survivin overexpression did not affect primary tumor growth of YUSAC2 or LOX subcutaneous tumors, or indices of proliferation or apoptosis, it significantly increased expression of α5 integrin in the primary tumors and formation of metastatic colonies in the lungs. Additionally, Survivin overexpression resulted in enhanced lung colony formation following intravenous (i.v.) injection of tumor cells in vivo and increased adherence to fibronectin-coated plastic in vitro. Importantly, in vivo inhibition of α5 integrin via intraperitoneal injection of an α5β1 integrin-blocking antibody significantly slowed tumor growth and reduced Survivin-enhanced pulmonary metastasis. Knockdown of α5 integrin in cells prior to i.v. injection also blocked Survivin-enhanced lung colony formation. These findings support a direct role for Survivin in melanoma metastasis, which requires α5 integrin and suggest that inhibitors of α5 integrin may be useful in combating this process.

Anti-apoptotic proteins on guard of melanoma cell survival

Apoptosis plays a pivotal role in sustaining proper tissue development and homeostasis. Evading apoptosis by cancer cells is a part of their adaption to microenvironment and therapies. Cellular integrity is predominantly maintained by pro-survival members of Bcl-2 family and IAPs. Melanoma cells are characterized by a labile and stage-dependent phenotype. Pro-survival molecules can protect melanoma cells from apoptosis and mediate other processes, thus enhancing aggressive phenotype. The essential role of Bcl-2, Mcl-1, Bcl-X(L), livin, survivin and XIAP was implicated for melanoma, often in a tumor stage-dependent fashion. In this review, the current knowledge of pro-survival machinery in melanoma is discussed.

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.

Impacting tumor cell-fate by targeting the inhibitor of apoptosis protein survivin

Survivin (BIRC5), a member of the inhibitor of apoptosis protein (IAP) family that inhibits caspases and blocks cell death is highly expressed in cancer and is associated with a poorer clinical outcome. Functioning simultaneously during cell division and apoptosis inhibition, survivin plays a pivotal role in determining cell survival. Survivin has consistently been identified by molecular profiling analysis to be associated with higher tumor grade, more advanced disease, abbreviated survival, accelerated rates of recurrence, and chemotherapy and radiation resistance. Survivin's differential expression in cancer compared to normal tissue and its role as a nodal protein in a number of cellular pathways make it a highly flexible therapeutic target, suitable for small-molecule inhibitiors, molecular antagonists, and vaccination-based therapies. By targeting survivin it is hoped that multiple tumor signaling circuitries may be simultaneously disabled. This effect may be applicable to many tumor histologies irrespective of specific genetic makeup. To date, survivin inhibitors have shown modest activity as single agents, but it is anticipated that when given in combination with cytotoxic chemotherapy or monoclonal antibodies they may exhibit enhanced efficacy. This review discusses the complex circuitry of survivin in human cancers and highlights clinical trials involving novel agents that target this important protein.

Molecular targeted therapy for patients with melanoma: the promise of MAPK pathway inhibition and beyond

IMPORTANCE OF THE FIELD

Recent discoveries have expanded the understanding of the molecular signaling events critical to melanomagenesis and led to the development of targeted therapeutic agents that are revolutionizing the treatment of patients with advanced melanoma.

AREAS COVERED IN THIS REVIEW

This article reviews current therapy and its limitations, describes the key pathogenic mechanisms in melanoma for which inhibitors have been tested, and summarizes the results of clinical trials involving molecularly targeted agents in this disease.

WHAT THE READER WILL GAIN

There has been an explosion of preclinical and clinical research aimed at targeting the key molecular alterations in melanoma for therapeutic benefit. These findings will be presented and placed in the proper clinical context, affording information regarding the current molecular targets in the melanoma and the activity and limitations of therapeutic agents directed against them.

TAKE HOME MESSAGE

Greater understanding of the pathogenic mechanisms underlying melanoma development has prompted the development of new therapeutic approaches aimed at counteracting these processes. While progress made over the past few years has generated considerable excitement, the benefits of these new therapies are still limited by incomplete and transient tumor regressions. It is hoped that with further investigation, particularly into mechanisms of treatment de novo and acquired treatment resistance, these limitations can be overcome.

The essential role of evasion from cell death in cancer

The link between evasion of apoptosis and the development of cellular hyperplasia and ultimately cancer is implicitly clear if one considers how many cells are produced each day and, hence, how many cells must die to make room for the new ones (reviewed in Raff, 1996). Furthermore, cells are frequently experiencing noxious stimuli that can cause lesions in their DNA and faults in DNA replication can occur during cellular proliferation. Such DNA damage needs to be repaired efficiently or cells with irreparable damage must be killed to prevent subsequent division of aberrant cells that may fuel tumorigenesis (reviewed in Weinberg, 2007). The detection of genetic lesions in human cancers that activate prosurvival genes or disable proapoptotic genes have provided the first evidence that defects in programmed cell death can cause cancer (Tagawa et al., 2005; Tsujimoto et al., 1984; Vaux, Cory, and Adams, 1988) and this concept was proven by studies with genetically modified mice (Egle et al., 2004b; Strasser et al., 1990a). It is therefore now widely accepted that evasion of apoptosis is a requirement for both neoplastic transformation and sustained growth of cancer cells (reviewed in Cory and Adams, 2002; Hanahan and Weinberg, 2000; Weinberg, 2007). Importantly, apoptosis is also a major contributor to anticancer therapy-induced killing of tumor cells (reviewed in Cory and Adams, 2002; Cragg et al., 2009). Consequently, a detailed understanding of apoptotic cell death will help to better comprehend the complexities of tumorigenesis and should assist with the development of improved targeted therapies for cancer based on the direct activation of the apoptotic machinery (reviewed in Lessene, Czabotar, and Colman, 2008).

Born to be alive: a role for the BCL-2 family in melanoma tumor cell survival, apoptosis, and treatment

The global incidence of melanoma has dramatically increased during the recent decades, yet the advancement of primary and adjuvant therapies has not kept a similar pace. The development of melanoma is often centered on cellular signaling that hyper-activates survival pathways, while inducing a concomitant blockade to cell death. Aberrations in cell death signaling not only promote tumor survival and enhanced metastatic potential, but also create resistance to anti-tumor strategies. Chemotherapeutic agents target melanoma tumor cells by inducing a form of cell death called apoptosis, which is governed by the BCL-2 family of proteins. The BCL-2 family is comprised of anti-apoptotic proteins (e.g., BCL-2, BCL-xL, and MCL-1) and pro-apoptotic proteins (e.g., BAK, BAX, and BIM), and their coordinated regulation and function are essential for optimal responses to chemotherapeutics. Here we will discuss what is currently known about the mechanisms of BCL-2 family function with a focus on the signaling pathways that maintain melanoma tumor cell survival. Importantly, we will critically evaluate the literature regarding how chemotherapeutic strategies directly impact on BCL-2 family function and offer several suggestions for future regimens to target melanoma and enhance patient survival.

Survivin enhances motility of melanoma cells by supporting Akt activation and {alpha}5 integrin upregulation

Survivin expression in melanoma is inversely correlated with patient survival. Transgenic mice harboring melanocyte-specific overexpression of survivin exhibit increased susceptibility to UV-induced melanoma and metastatic progression. To understand the mechanistic basis for metastatic progression, we investigated the effects of survivin on the motility of human melanocytes and melanoma cells. We found that survivin overexpression enhanced migration on fibronectin and invasion through Matrigel, whereas survivin knockdown under subapoptotic conditions blocked migration and invasion. In melanocytes, survivin overexpression activated the Akt and mitogen-activated protein kinase pathways. Akt phosphorylation was required for survivin-enhanced migration and invasion, whereas Erk phosphorylation was required only for enhanced invasion. In both melanocytes and melanoma cells, survivin overexpression was associated with upregulation of α5 integrin (fibronectin receptor component), the antibody-mediated blockade or RNA interference-mediated knockdown of which blocked survivin-enhanced migration. Knockdown of α5 integrin did not affect Akt activation, but inhibition of Akt phosphorylation prevented α5 integrin upregulation elicited by survivin overexpression. Together, our results showed that survivin enhanced the migration and invasion of melanocytic cells and suggested that survivin may promote melanoma metastasis by supporting Akt-dependent upregulation of α5 integrin.

Molecular-targeted therapy in malignant melanoma

Malignant melanoma is a deadly disease in which standard treatment options have remained remarkably static over the past 30 years. Recent discoveries have expanded the understanding of the molecular processes critical to melanomagenesis. During this same time period, therapeutic agents have been developed that target these processes, leading to an explosion of preclinical research. Several agents that have shown promise in the preclinical setting have now entered clinical trials. To date, the success of these molecularly targeted approaches as single agents has been limited. Although more encouraging results have been seen when these agents have been used in combination with cytotoxic therapy, the specific contribution of the targeted agents to the observed anti-tumor effects remains to be established in randomized controlled Phase III trials. This article presents a review of the limitations of current therapy, a description of key pathogenic mechanisms for which inhibitors exist and a summary of therapeutic trials of molecularly targeted agents in this disease.

Apoptosis and cancer: the genesis of a research field

In multicellular organisms, the total number of cells is a balance between the cell-generating effects of mitosis and cell death that is induced through apoptosis. A disruption of this delicate balance can lead to the development of cancer. This Timeline article focuses on how the field of apoptosis biology has developed in the context of its contribution to our understanding of cell death, or lack of it, in the development of malignant disease. It traces the course of research from key discoveries in fundamental biology to potential therapeutic applications.

Caspases and inhibitor of apoptosis proteins in cutaneous and mucosal melanoma: expression profile and clinicopathologic significance

Malignant melanoma is characterized by apoptotic dysfunction, presumably due to abnormal expression of caspases and inhibitor of apoptosis proteins. However, the expression status and clinicopathologic significance of caspases and inhibitor of apoptosis proteins in cutaneous and particularly in mucosal melanomas have not been established. We investigated the expression of the major caspases (CASP3, 6, 7, 8, 9, and 10) and inhibitor of apoptosis proteins (survivin, CIAP1, CIAP2, XIAP, and Livin) by immunohistochemistry in 52 primary cutaneous and 25 mucosal melanomas, and 24 common nevi. Clinicopathologic and prognostic significance was investigated by statistical analysis. Our data showed that the significantly up-regulated inhibitor of apoptosis proteins in primary cutaneous and mucosal melanomas as compared with nevus (P < .01) were survivin, CIAP1, CIAP2, and Livin. Percentage of cases with positive caspase or IAP immunostaining was not significantly different between primary cutaneous and mucosal melanomas or between lower- and higher-stage melanomas (P > .05). Tumor location (cutaneous versus mucosal), stage, and positive cytoplasmic and nuclear survivin staining correlated significantly with prognosis by univariate analysis (P < .01). Multivariate analysis by Cox regression model showed that the most useful prognostic indicators were tumor location (cutaneous versus mucosal, relative risk = 6.021, 95% confidence interval = 2.623 approximately 13.821, P = .000), stage (relative risk = 4.129, 95% confidence interval = 1.817 approximately 9.383, P = .001), and nuclear survivin staining (relative risk = 3.383, 95% confidence interval = 1.137 approximately 10.008, P = .028).

Melanoma biomarkers: current status and vision for the future

Melanoma is the leading cause of death from skin cancer in industrialized countries. Clinical and histological variables such as primary tumor invasion, ulceration, and lymph node status might fail to identify early-stage disease that will eventually progress. Tumor biomarkers might help to identify patients with early-stage melanoma who are likely to develop advanced disease and would benefit from additional therapies. These biomarkers offer the possibility of improved tumor staging through the molecular detection of microscopic lymph node metastases that are not visible on routine histological examination. We focus on biomarkers localized to the tumor tissue and those of prognostic value. We give an overview of the melanoma biomarkers that are most helpful for prediction of patients' outcomes, and discuss the primary melanoma biomarkers that have been shown to be of prognostic significance independent of primary tumor thickness and other common clinical prognostic indicators. Although such tumor-associated biomarkers are thought to have the greatest potential, a lack of reliable data makes their true clinical utility difficult to determine. We conclude that several biomarkers show promise in early studies; however, additional large-scale studies are warranted. We suggest cautious optimism for the field of melanoma biomarkers, which we expect to be translated into clinical practice over the next few years.

Nuclear and cytoplasmic cellular distribution of survivin as survival predictor in resected non-small-cell lung cancer

AIM

Survivin is a member of the inhibitors of apoptosis (IAP) gene family that acts through pathways different from those involving the bcl-2 family. Largely undetectable in normal adult tissues, survivin is deregulated in most human cancers including non-small-cell lung cancer (NSCLC) and may represent a tumor marker with prognostic and therapeutic implications. Aim of our study was to determine the prognostic role of survivin as an apoptosis-related biomarker in a series of resected NSCLC patients.

METHODS

A retrospective series of resected NSCLC patients were retrieved from the files of the Regina Elena National Cancer Institute. Survivin was detected by immunohistochemistry (IHC) using a polyclonal antibody. Survivin displayed two kinds of immunoreactivity: (i) a diffuse cytoplasmic staining and (ii) a distinct nuclear staining. A score-scale to distinguish positive (score 1-2) vs. negative (score 0) pattern was applied. Clinical and biological (nuclear and cytoplasmic survivin staining) covariables were screened for a prognostic relationship with overall survival (OS) and disease-free survival (DFS) into the univariate and multivariate analyses.

RESULTS

Data referring to 116 NSCLC patients who underwent surgery for stage I-IIIA NSCLC were collected. Multivariate analyses identified tumor size, nodal status and nuclear, but not cytoplasmic, expression of survivin as significant independent predictors of OS, with a hazard ratio of 2.40 (95% CI 1.44, 3.99, p=0.001), 2.03 (95% CI 1.26, 3.26, p=0.003) and 1.83 (95% CI 1.01, 3.30, p=0.044), respectively. Median OS for nuclear survivin positive (score 1-2) and negative (score 0) patients were 23 months (95% CI 15, 31) and 36 months (95% CI 1, 76), respectively (p=0.01); five-year survival for score 1-2 and score 0 patients were 20% and 44.5%, respectively. Conversely, no significant impact on survival is found when patients are stratified according to cytoplasmic survivin expression.

CONCLUSIONS

Data presented herein open the issue that prognosis of stage I-IIIA NSCLC can be linked to the cellular pattern of distribution of survivin.

Comparison of pHH3, Ki-67, and survivin immunoreactivity in benign and malignant melanocytic lesions

Differentiating malignant melanoma from benign melanocytic lesions can be challenging. We undertook this study to evaluate the use of the immunohistochemical mitosis marker phospho-Histone H3 (pHH3) and the proliferation markers Ki-67 and survivin in separating malignant melanoma from benign nevi. Sixty-six melanocytic lesions (18 malignant melanomas, 8 Spitz nevi, 20 dysplastic nevi, and 20 compound nevi) were stained with antibodies to pHH3, Ki-67, and survivin. No pHH3 expression was detected in the dermis of compound and dysplastic nevi. Rare mitoses were observed in the superficial dermis in 3 of 8 Spitz nevi (37%). Staining for pHH3 was higher in malignant melanomas [average 25 per 10 high-power field (HPF), range 2-75 per 10 HPF] than in Spitz nevi (average 0.5 per 10 HPF, range 0-2 per 10 HPF) and was heterogeneously distributed in the malignant melanomas compared with a superficial dermal location in Spitz nevi. There was no cytoplasmic staining for survivin in any of the 66 melanocytic lesions and no nuclear staining in any of the benign ones. Survivin nuclear staining was present in 12 of 18 cases of malignant melanoma (67%) with an average index of 7% (range 0%-15%). In benign melanocytic lesions, the Ki-67 index was less than 5% (range 0%-4%) and staining was present close to the dermo-epidermal junction compared with an average index of 27% in melanomas (range 5%-50%) and a generally heterogeneous pattern of staining throughout the dermis. pHH3 and Ki-67 can be useful adjuncts to histopathology to separate malignant melanoma from benign nevi. pHH3 is especially useful to highlight mitoses and to rapidly assess the mitotic activity in melanocytic lesions.

Circulating levels of vascular endothelial growth factor (VEGF), matrix metalloproteinase-3 (MMP-3), and BCL-2 in malignant melanoma

Vascular endothelial growth factor (VEGF) is a critical regulator of angiogenesis that stimulates proliferation, migration, and metastasis of melanoma. In literature, all studies concerning influences of matrix metalloproteinases (MMPs) and antiapoptotic proteins on VEGF-induced angiogenesis in melanoma patients have been performed in tissue scale in melanoma. The objective of this study was to determine the value of circulating serum VEGF and its possible mechanisms of angiogenesis by circulating VEGF, MMP-3, and Bcl-2 in patients with melanoma. Fifty-one patients with cutaneous melanoma pathologically verified at different stages, and eighteen healthy controls were investigated. Serum VEGF, MMP-3, and Bcl-2 levels were quantitatively analyzed by ELISA. The serum VEGF (P = 0.034) and Bcl-2 (P = 0.005) levels were significantly higher in patients with melanoma than in the control group. However, there was no significant difference in the serum MMP-3 level between melanoma patients and controls (P = 0.51). The serum levels of VEGF were significantly influenced only by Breslow thickness (P = 0.045) and mitosis (0.039) and were not positively correlated with the stage of the disease. Among serum parameters, a significant relationship was found only between serum levels of VEGF and MMP-3 (r = 0.32, P = 0.023). In conclusion, our study demonstrates increased concentrations of VEGF and Bcl-2, but not MMP-3, in serum of melanoma patients regardless of the stage of the disease. VEGF may be a potential endothelial cell growth and survival factor. The mechanism of VEGF regulation of angiogenesis may be in part due to enhanced proliferation and survival of endothelial cells by differential expression of antiapoptotic genes and in part by activation of MMPs.

Survivin repression by p53, Rb and E2F2 in normal human melanocytes

The inhibitor of apoptosis protein survivin is a dual mediator of apoptosis resistance and cell cycle progression and is highly expressed in cancer. We have shown previously that survivin is up-regulated in melanoma compared with normal melanocytes, is required for melanoma cell viability, and that melanocyte expression of survivin predisposes mice to ultraviolet-induced melanoma and metastasis. The mechanism of survivin up-regulation in the course of melanocyte transformation and its repression in normal melanocytes, however, has not been clearly defined. We show here that p53 and retinoblastoma (Rb), at basal levels and in the absence of any activating stimuli, are both required to repress survivin transcription in normal human melanocytes. Survivin repression in melanocytes does not involve alterations in protein stability or promoter methylation. p53 and Rb (via E2Fs) regulate survivin expression by direct binding to the survivin promoter; p53 also affects survivin expression by activating p21. We demonstrate a novel role for E2F2 in the negative regulation of survivin expression. In addition, we identify a novel E2F-binding site in the survivin promoter and show that mutation of either the p53- or E2F-binding sites is sufficient to increase promoter activity. These studies suggest that compromise of either p53 or Rb pathways during melanocyte transformation leads to up-regulation of survivin expression in melanoma.

Melanocyte expression of survivin promotes development and metastasis of UV-induced melanoma in HGF-transgenic mice

We previously found the apoptosis inhibitor Survivin to be expressed in melanocytic nevi and melanoma but not in normal melanocytes. To investigate the role of Survivin in melanoma development and progression, we examined the consequences of forced Survivin expression in melanocytes in vivo. Transgenic (Tg) mouse lines (Dct-Survivin) were generated with melanocyte-specific expression of Survivin, and melanocytes grown from Dct-Survivin mice expressed Survivin. Dct-Survivin melanocytes exhibited decreased susceptibility to UV-induced apoptosis but no difference in proliferative capacity compared with melanocytes derived from non-Tg littermates. Induction of nevi in Dct-Survivin and non-Tg mice by topical application of 7,12-dimethylbenz(a)anthracene did not reveal significant differences in lesion onset (median, 10 weeks) or density (4 lesions per mouse after 15 weeks). Dct-Survivin mice were bred with melanoma-prone MH19/HGF-B6 Tg mice, and all progeny expressing either individual, neither, or both (Survivin/HGF) transgenes were UV-treated as neonates and then monitored for 43 weeks. Melanocytes in neonatal Survivin+/HGF+ mouse skin were less susceptible to UV-induced apoptosis than those from Survivin-/HGF+ mice. Onset of melanocytic tumors was earlier (median, 18 versus 24 weeks; P = 0.01, log-rank test), and overall tumor density was greater (7.7 versus 5.2 tumors per mouse; P = 0.04) in Survivin+/HGF+ compared with Survivin-/HGF+ mice. Strikingly, melanomas arising in Survivin+/HGF+ mice showed a greater tendency for lymph node (35% versus 0%; P = 0.04) and lung (53% versus 22%) metastasis and lower rates of spontaneous apoptosis than those in Survivin-/HGF+ mice. These studies show a role for Survivin in promoting both early and late events of UV-induced melanoma development in vivo.

Nuclear survivin is associated with disease recurrence and poor survival in patients with cutaneous malignant melanoma

AIMS

Survivin is expressed in neoplastic cells and appears to be associated with resistance to therapy and shorter survival in various types of tumours. The aim of the present study was to determine whether nuclear or cytoplasmic expression of survivin is related to disease recurrence and overall survival of patients with Stage I and II melanoma according to the American Joint Committee on Cancer (AJCC) staging system.

METHODS AND RESULTS

Immunohistochemistry was performed on formalin-fixed paraffin-embedded sections of primary cutaneous melanoma from 50 patients. Survival rates were estimated using the Kaplan-Meier method and compared using the log rank test. Association of clinical variables (gender, age, tumour location, thickness, Clark level and AJCC stage) with survivin expression was analysed by Fisher's exact test. Patients with nuclear immunoreactivity for survivin had an increased risk of disease recurrence during the first three postoperative years (P < 0.05) and of death (P < 0.05). Cytoplasmic immunoreactivity was not correlated with either survival or clinical variables.

CONCLUSIONS

Nuclear presence of survivin may be an independent biomarker for disease recurrence and overall survival in patients with Stage I and II melanoma.