Inhibition of growth and invasive ability of melanoma by inactivation of mutated BRAF with lentivirus-mediated RNA interference

Sumimoto, Hidetoshi; Miyagishi, Makoto; Miyoshi, Hiroyuki; Yamagata, Shizuko; Shimizu, Ayako; Taira, Kazunari; Kawakami, Yutaka

doi:10.1038/sj.onc.1207812

Cited by 174 publications

(161 citation statements)

References 40 publications

Supporting

Mentioning

150

Contrasting

Unclassified

Order By: Relevance

“…These results argue against the possibility that alterations in cyclin D1 and p27 Kip1 are due to off-target siRNA effects. Consistent with previous publications (Hingorani et al, 2003;Karasarides et al, 2004;Sumimoto et al, 2004), B-RAF knockdown in WM793 cells inhibited cell growth (Figure 1g). Furthermore, B-RAF knockdown cells showed decreased phosphorylation of Rb protein and expression of cyclin A, two markers of G1 cell cycle progression (Figure 1h) (Figure 2d).…”

Section: Resultssupporting

confidence: 93%

“…These data complement our previous studies showing that expression of mutant B-RAF is sufficient to upregulate cyclin D1 and downregulate p27 Kip1 in human melanocytes, and that pharmacological inhibition of the B-RAF effector, MEK, has the opposite effects in melanoma cells (Bhatt et al, 2005). Our findings also provide mechanistic details that underlie others' studies in melanoma cells showing that B-RAF-MEK signaling is necessary for S-phase entry, proliferation and anchorage-independent growth in vitro (Collisson et al, 2003;Hingorani et al, 2003;Karasarides et al, 2004;Sumimoto et al, 2004), and growth in vivo (Collisson et al, 2003;Sumimoto et al, 2004;Sharma et al, 2005), and the report that B-RAF V600E transforms mouse melanocytes (Wellbrock et al, 2004b). It is possible that wild-type B-RAF, which is activated by autocrine growth factor signaling (Satyamoorthy et al, 2003), may also contribute to the regulation of cyclin D1 and p27 Kip1 in our experiments utilizing siRNA that targets both mutant and wild-type B-RAF.…”

Section: Discussionsupporting

confidence: 67%

See 1 more Smart Citation

Mutant B-RAF signaling and cyclin D1 regulate Cks1/S-phase kinase-associated protein 2-mediated degradation of p27Kip1 in human melanoma cells

Bhatt

Spofford

et al. 2006

Oncogene

View full text Add to dashboard Cite

Section: Resultssupporting

confidence: 93%

Section: Discussionsupporting

confidence: 67%

Mutant B-RAF signaling and cyclin D1 regulate Cks1/S-phase kinase-associated protein 2-mediated degradation of p27Kip1 in human melanoma cells

Bhatt

Spofford

et al. 2006

Oncogene

View full text Add to dashboard Cite

“…35 Furthermore, another study demonstrated that RNAi directed at the V600E BRAF mutation inhibited matrigel invasion of human melanoma cells and decreased metalloproteinase activity and b1 integrin expression. 36 Interestingly, the 397 cells used in our study also contain homozygous deletions of p16 and ARF in the CDKN2A gene, which may represent one additional mechanism that further prevents these cells from undergoing apoptosis.…”

Section: Discussionmentioning

confidence: 79%

Suppression of oncogenic NRAS by RNA interference induces apoptosis of human melanoma cells

Eskandarpour¹,

Kiaii²,

Zhu³

et al. 2005

Intl Journal of Cancer

View full text Add to dashboard Cite

The majority of human melanomas harbor activating mutations in either the BRAF or NRAS gene. To date, the role of oncogenic NRAS in melanoma remains poorly defined and no current therapies are directed at specifically suppressing oncogenic NRAS in human melanoma tumors. The aim of our study, therefore, was to investigate the effects of suppressing oncogenic NRAS in human melanoma cell lines in vitro. Using both small interfering RNAand plasmid based-RNA interference techniques, oncogenic NRAS was specifically suppressed in 2 human melanoma cell lines, 224 and BL, which harbor a codon 61 CAA (glutamine) to CGA (arginine) NRAS mutation. Suppression of oncogenic NRAS in these cell lines resulted in increased apoptosis. Furthermore, in 224 cells we demonstrated decreased phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, and reduced expression of NF-kB and cyclin D1 in the N-Ras signaling pathway. In contrast, RNA interference directed at wild-type (WT) NRAS had no significant effect on apoptosis of 224 cells or 2 human melanoma cell lines (A375 and 397) containing WT NRAS but a codon 600 GTG (valine) to GAG (glutamate) mutation in BRAF. These data suggest that oncogenic NRAS is important for avoidance of apoptosis in melanomas that harbor the codon 61 NRAS mutation and emphasizes oncogenic NRAS as a therapeutic target in patients with tumors that harbor this mutation. ' 2005 Wiley-Liss, Inc.Key words: RNAi; melanoma; Ras; signal transduction; apoptosis Activation of Ras is a common molecular event in the etiology of human cancer. 1 The Ras proteins H-, K-and N-Ras are central regulators of cellular signal transduction processes leading to cell growth and differentiation. In the resting cell, Ras proteins are in the guanosine diphosphate (GDP)-bound inactive state. However, in response to receptor protein tyrosine kinases or other growth factor-dependent stimuli, these Ras proteins become activated by binding guanosine triphosphate (GTP). 2,3 Oncogenic mutations in codons 12, 13 and 61 of RAS genes prevent GTP hydrolysis, resulting in constitutively active Ras proteins. Such mutations that change the protooncogene RAS to an active oncogene are found in approximately 30 to 50% of human tumors. [4][5][6][7][8] Ras has also been demonstrated to be important for both the genesis and maintenance of melanoma. For instance, in a doxycycline-inducible H-Ras V12G mouse melanoma model, withdrawal of doxycycline was demonstrated to result in histological regression of primary and implanted tumors accompanied by marked apoptosis of melanoma cells. 9 Studies on melanoma tumors have confirmed that oncogenic activation of NRAS constitutes the predominant RAS alteration in cutaneous melanoma, with NRAS codon 61 mutations being the most common alterations and codon 12 and 13 mutations being less frequent. 6,7,10,11 In sporadic melanoma cases, the frequency of NRAS alterations reported varies in different studies. [12][13][14] In a study performed by our group, 28% of primary melanomas and 37% of metastatic tumo...

show abstract

“…144,145 Moreover, additional antisense approaches are currently tested for antitumor activity in preclinical models. So far, depletion of either B-RAF or mutant V600E B-RAF by small-interfering RNAs (siRNAs) reduced proliferation and invasiveness of melanoma cell lines, [146][147][148] and also the growth and vascular development of malignant melanoma tumors. 149 Reduction of in vivo tumor growth by application of C-RAF siRNA was also reported in xenograft models of human prostate 150 and also breast cancer.…”

Section: Raf Kinases and Cancer Drug Discoverymentioning

confidence: 99%

Raf kinases: Oncogenesis and drug discovery

Schreck

Rapp

2006

Intl Journal of Cancer

View full text Add to dashboard Cite

Raf kinase signaling has been thoroughly investigated over the last 20 years. A-Raf, B-Raf and C-Raf, the 3 mammalian members of the Raf family, are involved in a variety of cellular processes such as growth, proliferation, survival, differentiation and transformation. The detection of B-RAF mutations in a wide variety of human cancers, the description of wildtype and mutant B-RAF as tumor antigens in melanoma and the promising outcome of clinical trials evaluating the Raf inhibitor Nexavar 1 (Sorafenib, BAY 43-9006) have sparked a broad interest in the scientific community. After a short historical detour and an introduction into Raf kinase signaling, we are going to discuss here recent outcomes of Raf kinase research with respect to tumor formation and give an overview on current efforts to develop anticancer therapies interfering with aberrant Raf kinase signaling. ' 2006 Wiley-Liss, Inc.Key words: cancer; clinical trials; transformation; drug delivery; signal transduction; mitogenic cascade; Raf kinases Raf kinases: The historyIn 1983, the cloning of the acutely transforming replication-defective mouse type C virus 3611-MSV and characterization of its acquired oncogene was reported. 1 Since 3611-MSV induces rapidly growing f ibrosarcoma in mice, the transduced oncogene was called v-raf, whereas its cellular homologue was named c-raf. 1 Shortly thereafter, Bister and coworkers described the cloning of the avian acute leukemia retrovirus Mil Hill No. 2 (MH2). 2 MH2 was found to carry a second potential oncogene in addition to vmyc, which was termed v-mil, whereas its cellular counterpart was called c-mil. 3 Already a hybridization analysis and the gross comparison of restriction maps of v-raf and v-mil pointed at sequence homologies between these 2 genes. 4 By direct sequencing of both genes it was finally proven that 3611-MSV and MH2 have integrated orthologues of the same gene into their genomes. 5 In the following we are going to use the nomenclature for Raf kinases as proposed in a recent review from Wellbrock et al. 6 In contrast to all other oncogene kinases known at that time, no tyrosine kinase activity was detected in C-Raf. 7 Indeed, it was found that C-Raf is a serine/threonine kinase. 8,9 This and the observation that Raf coexists with the Myc oncogene in retroviruses 10 led to two novel concepts: (i) There is a tyrosine to serine phosphorylation switch as the growth factor signal enters the cell, and (ii) the mechanistic basis for cooperation between nuclear and cytoplasmic oncogenes as well as for signal transduction from cell surface receptors to the nucleus is the phosphorylation of transcription factor class oncogenes such as Myc. 11-13 Growth factor abrogation and oncogene cooperation studies were performed to corroborate this signaling scheme. 14-17 Additional important early findings were (i) the cooperation between Raf and Myc in growth factor independent proliferation, immortalization and tumor induction, 14,18,19 leading to the Raf-Myc balance model, 20 and (ii) the cell lineage-switch ...

show abstract

Inhibition of growth and invasive ability of melanoma by inactivation of mutated BRAF with lentivirus-mediated RNA interference

Cited by 174 publications

References 40 publications

Mutant B-RAF signaling and cyclin D1 regulate Cks1/S-phase kinase-associated protein 2-mediated degradation of p27Kip1 in human melanoma cells

Mutant B-RAF signaling and cyclin D1 regulate Cks1/S-phase kinase-associated protein 2-mediated degradation of p27Kip1 in human melanoma cells

Suppression of oncogenic NRAS by RNA interference induces apoptosis of human melanoma cells

Raf kinases: Oncogenesis and drug discovery

Contact Info

Product

Resources

About