Gene expression signature for classification of kidney tumors
The present invention provides a method for classification of kidney tumors through the analysis of the expression patterns of specific microRNAs and nucleic acid molecules relating thereto. Classification according to a microRNA expression framework allows optimization of treatment, and determination of specific therapy.
1. A method for classifying a kidney tumor sample obtained from a human subject as oncocytoma, clear cell renal cell carcinoma (RCC), papillary RCC, or chromophobe RCC, the method comprising:
(a) obtaining a kidney tumor sample from the human subject;
(b) determining by real-time PCR (RT-PCR) an expression profile of SEQ ID NOS: 1, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24-26, 28, 30, 32, 34, 36, 38, 41, 45, 47, 48, 56, 58, 60, 62, and 66 in the sample, wherein said RT-PCR comprises contacting the sample with forward and reverse primers, wherein each forward primer comprises at least 15-21 nucleotides identical to one of SEQ ID NOS: 1, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24-26, 28, 30, 32, 34, 36, 38, 41, 45, 47, 48, 56, 58, 60, 62, and 66, and wherein the forward primer comprising at least 15-21 nucleotides identical to SEQ ID NO: 14 comprises the sequence of SEQ ID NO: 84;
(c) comparing said expression profile to one or more reference values; and
(d) classifying the kidney tumor sample as oncocytoma, clear cell RCC, papillary RCC, or chromophobe RCC based on the expression profile of SEQ ID NOS: 1, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24-26, 28, 30, 32, 34, 36, 38, 41, 45, 47, 48, 56, 58, 60, 62, and 66 in the sample relative to the reference value, wherein:
an increase in the expression of SEQ ID NOS: 12, 14, 18, 25, 26, 28, 30, 36, 38, 41, 48, and 66 in the sample relative to the reference value is indicative of the presence of oncocytoma;
an increase in the expression of SEQ ID NOS: 32, 34, 36, 56, 58, 60, and 62 in the sample relative to the reference value is indicative of the presence of chromophobe RCC;
an increase in the expression of SEQ ID NOS: 1, 6, 16, 20, 22, 24, and 41 in the sample relative to the reference value is indicative of the presence of clear cell RCC; and
an increase in the expression of SEQ ID NOS: 4, 8, 10, 45, and 47 in the sample relative to the reference value is indicative of the presence of papillary RCC.
2. The method of claim 1 , wherein the kidney tumor sample is a fresh, frozen, fixed, wax embedded or formalin fixed paraffin-embedded (FFPE) tissue sample.
3. The method of claim 1 , wherein the RT-PCR method further comprises hybridization with a probe.
4. The method of claim 3 , wherein the probe comprises any one of SEQ ID NOS: 76-81.
5. The method of claim 1 , wherein the forward primers comprise at least one of SEQ ID NO: 82 for determining the expression profile of SEQ ID NO: 4; SEQ ID NO: 83 for determining the expression profile of SEQ ID NO: 41; SEQ ID NO: 85 for determining the expression profile of SEQ ID NO: 20; SEQ ID NO: 86 for determining the expression profile of SEQ ID NO: 34; and SEQ ID NO: 87 for determining the expression profile of SEQ ID NO: 25.
6. The method of claim 5 , wherein the reverse primer comprises the sequence of SEQ ID NO: 90.