Upregulation of rack-1 in melanoma and its use as a marker

Abstract

The present invention concerns a method for diagnosing a melanoma in a mammal comprising the detection of the overexpression of RACK-1 protein in a melanocytic cell of said mammal, and the deduction of the presence of a melanoma from the overexpression of RACK-1 protein. The invention is also directed to a method for determining the tumoral status of a melanocytic cell of a mammal, comprising the detection of overexpression of RACK-1 protein in the melanocytic cell, and the deduction of the tumoral state of said cell from the overexpression of RACK-1 protein.

1 . Method for determining the tumoral status of a melanocytic cell of a mammal, comprising:
 Detecting expression or overexpression of RACK-1 protein in the melanocytic cell,   relating the expression or overexpression of RACK-1 protein to a tumoral state for said cell.   
     
     
         2 . Method for diagnosing a melanoma in a mammal comprising:
 detecting expression/overexpression of RACK-1 protein in a melanocytic cell of said mammal,   relating the expression/overexpression of RACK-1 protein to the presence of a melanoma.   
     
     
         3 . Method for determining the tumoral status of a melanocytic cell of a mammal comprising:
 determining the level of expression of RACK-1 protein in the melanocytic cell,   comparing this level with a reference level, an increased level of RACK-1 protein expression in said melanocytic cell with respect to the reference level indicating the tumoral state of the cell.   
     
     
         4 . Method for diagnosing a melanoma in a mammal comprising:
 determining the level of RACK-1 protein expression in a melanocytic cell of said mammal,   comparing this level with a reference level, an increased level of RACK-1 protein expression in said melanocytic cell with respect to the reference level indicating the presence of a melanoma.   
     
     
         5 . Method according to  claim 3  or  4 , wherein said reference level is the level of RACK-1 protein expression in a non-tumoral melanocyte of the mammal. 
     
     
         6 . Method according to  claim 5 , wherein said non-tumoral melanocyte is a normal epidermal melanocyte or a normal choroidal melanocyte. 
     
     
         7 . Method according to  claim 3  or  4 , wherein the level of RACK-1 protein expression is defined by the level of protein RACK-1. 
     
     
         8 . Method according to  claim 7 , wherein the level of protein RACK-1 is determined by in situ immunoassay. 
     
     
         9 . Method according to  claim 3  or  4 , wherein the level of RACK-1 protein expression is defined by the level of mRNA corresponding to RACK-1 protein. 
     
     
         10 . Method according to  claim 9 , wherein the level of mRNA corresponding to RACK-1 protein is determined by in situ hybridisation. 
     
     
         11 . Method according to any one of  claims 1  to  4 , wherein said melanocytic cell is from a biopsy. 
     
     
         12 . Method according to any one of  claims 1  to  4 , wherein the presence of RACK-1 protein or the level of RACK-1 protein expression is determined by carrying out an immunological technique, an immunoassay, an immunohistochemistry assay, a confocal microscopy analysis, a ultraviolet spectroscopy, an electrochemical detection or an hybridisation autoradiography. 
     
     
         13 . Method according to  claim 12 , wherein said immunological technique is a technique employing specific monoclonal or polyclonal antibodies, an ELISA technique, an immunoenzymatic technique, an immunofluorescence technique, a radio-immunological technique or a chemo-immunological technique. 
     
     
         14 . Method according to  claim 2  or  4 , wherein said melanoma is a cutaneous malignant melanoma or a choroidal melanoma. 
     
     
         15 . Method for diagnosing a melanoma in a mammal comprising:
 bringing a biological sample from said mammal into contact in vitro, with a means for detecting melanocytic cells and a means for detecting RACK-1 protein expression;   determining whether melanocytic cells co-localise with RACK-1 protein expression, presence of melanocytic cells exhibiting RACK-1 protein expression being indicative of a melanoma.   
     
     
         16 . Method according to  claim 15  wherein said biological sample is a biopsy. 
     
     
         17 . Method according to  claim 16 , wherein said biopsy is a biopsy of lymp node, liver, lung, heart, spleen, eye or skin. 
     
     
         18 . Method according to any one of  claims 1  to  4  and  15 , wherein said mammal is a human. 
     
     
         19 . Method according to any one of  claims 1  to  4  and  15 , wherein said mammal is a pig, a cat, a dog or a horse. 
     
     
         20 . Method according to  claim 15 , wherein said means for detecting RACK-1 protein expression is a means for detecting the protein RACK-1. 
     
     
         21 . Method according to  claim 15 , wherein said means for detecting RACK-1 protein expression is an antibody, preferably a monoclonal antibody. 
     
     
         22 . Kit for diagnosing a melanoma in a mammal comprising a means for detecting RACK-1 protein expression. 
     
     
         23 . Kit according to  claim 22 , wherein said means is a means for detecting the protein RACK-1. 
     
     
         24 . Kit according to  claim 22 , wherein said means is an antibody, preferably a monoclonal antibody. 
     
     
         25 . Kit according to  claim 22 , further comprising a means for detecting melanocytic cells. 
     
     
         26 . Kit according to  claim 25 , wherein said means for detecting melanocytic cells is an antibody against the microphthalmia transcription factor MITF, an antibody against the dopachrome tautomerase DCT, an antibody against the tyrosinase TYR, an antibody against the tyrosinase-related protein 1 TRP1 or an antibody against any protein involved in the melanin synthesis pathway.