Frequency of PTEN alterations, TMPRSS2-ERG fusion and their association in prostate cancer

Phosphatase and tensin homolog (PTEN) gene aberration and trans membrane protease, serine 2 (TMPRSS2)-v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) fusion are the most prevalent genomic events in prostate cancer.

In this study we aimed to evaluate the frequency of PTEN alteration and TMPRSS2-ERG fusion and possible link between these two biomarkers in Iranian men.

We assessed 42 fresh frozen tissue samples of prostate cancer (PCA) obtained by radical prostatectomy, interrogating the TMPRSS2-ERG fusion gene along with PTEN gene status using Real Time PCR and FISH methods.

Using Real Time PCR we identified the TMPRSS2-ERG fusion in 64% (27/42) of tumor samples, which was confirmed by FISH technique, giving 21 positive samples with deletion, suggesting the presence of TMPRSS2-ERG fusion gene. By contrast, PTEN deletion was detected in 52% (11/21) of PCA samples, which all showed low expression in Real Time. Concomitance of PTEN deletion or low expression and TMPRSS2-ERG fusion was present in PCA samples (P=0. 005). All of the PTEN deletion samples showed TMPRSS2-ERG fusion, (11/11, 100%) while not all of the TMPRSS2-ERG fusion positive samples showed PTEN deletion. None of 29 cases of BPH and 8 cases of normal zone of tumor tissue showed TMPRSS2-ERG fusion.

These results indicate that PTEN loss occurs in cooperation with TMPRSS2-ERG fusion in PCA. While the majority of PCA samples harbor TMPRSS2-ERG fusion as well as PTEN gene deletion, normal tissues do not show these molecular aberrations.

Gene. 2015 Sep 28 [Epub ahead of print]

Zahra Rafiei Fallahabadi, Mohammad Reza Noori Daloii, Reza Mahdian, Farhkondeh Behjati, Mohamad Ali Shokrgozar, Maryam Abolhasani, Mojgan Asgari, Hossein Shahrokh

Molecular Medicine Department, Pasteur Institute of Iran, Tehran, Iran; National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran; Medical Genetics Department, Tehran University of Medical Sciences, Tehran, Iran. , Medical Genetics Department, Tehran University of Medical Sciences, Tehran, Iran. , Molecular Medicine Department, Pasteur Institute of Iran, Tehran, Iran. Genetics Research Center, University of Social Walfare and Rehabilitation Sciences, Tehran, Iran. , National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran. , Oncopathology Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Pathology, Hasheminejad kidney Center, Iran University of Medical Sciences, Tehran, Iran. , Oncopathology Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Pathology, Hasheminejad kidney Center, Iran University of Medical Sciences, Tehran, Iran. , Department of Urology, Hasheminejad kidney Center, Iran University of Medical Sciences, Tehran, Iran.

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