Supplementary Table S3 from Two types of human malignant melanoma cell lines revealed by expression patterns of mitochondrial and survival-apoptosis genes: implications for malignant melanoma therapy (original) (raw)

Two types of human malignant melanoma cell lines revealed by expression patterns of mitochondrial and survival-apoptosis genes: implications for malignant melanoma therapy

Molecular Cancer Therapeutics, 2009

Human malignant melanoma has poor prognosis because of resistance to apoptosis and therapy. We describe identification of the expression profile of 1,037 mitochondria-focused genes and 84 survival-apoptosis genes in 21 malignant melanoma cell lines and 3 normal melanocyte controls using recently developed hMitChip3 cDNA microarrays. Unsupervised hierarchical clustering analysis of 1,037 informative genes, and 84 survival-apoptosis genes, classified these malignant melanoma cell lines into type A (n = 12) and type B (n = 9). Three hundred fiftyfive of 1,037 (34.2%) genes displayed significant (P ≤ 0.030; false discovery rate ≤ 3.68%) differences (±≥2.0fold) in average expression, with 197 genes higher and 158 genes lower in type A than in type B. Of 84 genes with known survival-apoptosis functions, 38 (45.2%) displayed the significant (P < 0.001; false discovery rate < 0.15%) difference. Antiapoptotic (BCL2, BCL2A1, PPARD, and RAF1), antioxidant (MT3, PRDX5, PRDX3, GPX4, GLRX2, and GSR), and proapoptotic (BAD, BNIP1, APAF1, BNIP3L, CASP7, CYCS, CASP1, and VDAC1) genes expressed at higher levels in type A than in type B, whereas the different set of antiapoptotic (PSEN1, PPP2CA, API5, PPP2R1B, PPP2R1A, and FIS1), antioxidant (HSPD1, GSS, SOD1, ATOX1, and CAT), and proapoptotic (ENDOG, BAK1, CASP2, CASP4, PDCD5, HTRA2, SEPT4, TNFSF10, and PRODH) genes expressed at lower levels in type A than in type B. Microarray data were validated by quantitative reverse transcription-PCR. These results showed the presence of two types of malignant melanoma, each with a specific set of dysregulated survival-apoptosis genes, which may prove useful for development of new molecular targets for therapeutic intervention and novel diagnostic biomarkers for treatment and prognosis of malignant melanoma.

TNF-related apoptosis-inducing ligand-induced apoptosis of melanoma is associated with changes in mitochondrial membrane potential and perinuclear clustering of …

The Journal of …, 2000

Past studies have shown that TNF-related apoptosis-inducing ligand (TRAIL) induced apoptosis in a high proportion of cultured melanoma by caspase-dependent mechanisms. In the present studies we have examined whether TRAIL-induced apoptosis of melanoma was mediated by direct activation of effector caspases or whether apoptosis was dependent on changes in mitochondrial membrane potential (MMP) and mitochondrial-dependent pathways of apoptosis. Changes in MMP were measured by fluorescent emission from rhodamine 123 in mitochondria. TRAIL, but not TNF-␣ or Fas ligand, was shown to induce marked changes in MMP in melanoma, which showed a high correlation with TRAIL-induced apoptosis. This was associated with activation of proapoptotic protein Bid and release of cytochrome c into the cytosol. Overexpression of B cell lymphoma gene 2 (Bcl-2) inhibited TRAIL-induced release of cytochrome c, changes in MMP, and apoptosis. The pan caspase inhibitor z-Val-Ala-Asp-fluoromethylketone (zVAD-fmk) and the inhibitor of caspase-8 (z-Ile-Glu-Thr-Asp-fluoromethylketone; zIETD-fmk) blocked changes in MMP and apoptosis, suggesting that the changes in MMP were dependent on activation of caspase-8. Activation of caspase-9 also appeared necessary for TRAIL-induced apoptosis of melanoma. In addition, TRAIL, but not TNF-␣ or Fas ligand, was shown to induce clustering of mitochondria around the nucleus. This process was not essential for apoptosis but appeared to increase the rate of apoptosis. Taken together, these results suggest that TRAIL induces apoptosis of melanoma cells by recruitment of mitochondrial pathways to apoptosis that are dependent on activation of caspase-8. Therefore, factors that regulate the mitochondrial pathway may be important determinants of TRAIL-induced apoptosis of melanoma.

Molecular mechanism underlying differential apoptosis between human melanoma cell lines UACC903 and UACC903(+6) revealed by mitochondria-focused cDNA microarrays

Apoptosis, 2008

Human malignant melanoma cell line UACC903 is resistant to apoptosis while chromosome 6-mediated suppressed cell line UACC903(+6) is sensitive. Here, we describe identification of differential molecular pathways underlying this difference. Using our recently developed mitochondria-focused cDNA microarrays, we identified 154 differentially expressed genes including proapoptotic (BAK1 [6p21.3], BCAP31, BNIP1, CASP3, CASP6, FAS, FDX1, FDXR, TNFSF10 and VDAC1) and antiapoptotic (BCL2L1, CLN3 and MCL1) genes. Expression of these pro-and anti-apoptotic genes was higher in UACC903(+6) than in UACC903 before UV treatment and was altered after UV treatment. qRT-PCR and Western blots validated microarray results. Our bioinformatic analysis mapped these genes to differential molecular pathways that predict resistance and sensitivity of UACC903 and UACC903(+6) to apoptosis respectively. The pathways were functionally confirmed by the FAS ligand-induced cell death and by siRNA knockdown of BAK1 protein. These results demonstrated the differential molecular pathways underlying survival and apoptosis of UACC903 and UACC903(+6) cell lines.

Mitochondrial Respiration - An Important Therapeutic Target in Melanoma

PLoS ONE, 2012

The importance of mitochondria as oxygen sensors as well as producers of ATP and reactive oxygen species (ROS) has recently become a focal point of cancer research. However, in the case of melanoma, little information is available to what extent cellular bioenergetics processes contribute to the progression of the disease and related to it, whether oxidative phosphorylation (OXPHOS) has a prominent role in advanced melanoma. In this study we demonstrate that compared to melanocytes, metastatic melanoma cells have elevated levels of OXPHOS. Furthermore, treating metastatic melanoma cells with the drug, Elesclomol, which induces cancer cell apoptosis through oxidative stress, we document by way of stable isotope labeling with amino acids in cell culture (SILAC) that proteins participating in OXPHOS are downregulated. We also provide evidence that melanoma cells with high levels of glycolysis are more resistant to Elesclomol. We further show that Elesclomol upregulates hypoxia inducible factor 1-a (HIF-1a), and that prolonged exposure of melanoma cells to this drug leads to selection of melanoma cells with high levels of glycolysis. Taken together, our findings suggest that molecular targeting of OXPHOS may have efficacy for advanced melanoma.

Mitochondrial Dna Deletions in Skin from Melanoma Patients

Ethnicity Disease, 2008

We measured the cellular levels of two types of mitochondrial DNA (mtDNA) deletions-the 4977-bp common deletion and recently identified UVB-induced deletion of 5128 bp-in apparently normal skin obtained from wide excisions in melanoma patients. The number of deleted mtDNAs as well as the total mtDNA copy number was highly variable, but the number of deletions increased with age of the donor almost 12-fold across the age range of the patients. Patients were scored for degree of overall pigmentation and response to sunlight by a phenotypic index (PI). The relative levels of both types of mtDNA deletions were much more abundant in the intermediate PI groups compared with either the low or high PI groups. In the intermediate PI group, melanomas were also seen later in life. Unexpectedly, the complement of total mitochondrial genomes was more than twofold higher in the low PI group than in the other PI groups. This may reflect a proliferative response to DNA damage induced by solar radiation in the highrisk group.