Expression analysis of peptide growth factors VEGF, FGF2, TGFB1, EGF and IGF1 in prostate cancer and benign prostatic hyperplasia

Peptide growth factors play an important role in several intracellular processes, such as cellular growth and differentiation, angiogenesis and apoptosis, as well as in carcinogenesis, since they contribute significantly to the malignant transformation. The prostate gland is abundant in growth factors. The two most known prostatic diseases, prostate cancer (PCa) and benign prostatic hyperplasia (BPH), are among the most common diseases that affect elderly men. This study was conducted using a quantitative real-time RT-PCR method in order to determine mRNA expression levels of peptide growth factors VEGF, FGF2, TGFB1, EGF, and IGF1 in tissue specimens from 42 patients with PCa, 42 with BPH, and 10 normal prostate samples obtained post-mortem from young individuals, in order to examine their association with prostatic hyperplasia and neoplasia. Our results show that in PCa, growth factors VEGF, EGF and FGF2 are overexpressed, while TGFB1 and IGF1 have reduced mRNA levels. In BPH, transcript levels of FGF2 and EGF are normal, while VEGF, TGFB1 and IGF1 exhibit downregulation. Further statistical analysis revealed that PCa patients with high levels of PSA blood levels have decreased FGF2 expression (p=0.016). Additionally, cancer patients with low Gleason score (<7) have increased EGF (p=0.035) and IGF1 (p=0.031) mRNA levels. IGF1 levels are also elevated in tumors with TNM stages T1-T2 (p=0.030). In BPH, older patients have reduced EGF expression (p=0.018), while IGF1 is overexpressed in younger patients (p=0.041). Additionally, the co-expression pattern of the five studied growth factors differs significantly among normal, benign and malignant prostate. These results implicate VEGF, FGF2, TGFB1, EGF and IGF1 in the development of both PCa and BPH, rendering them potential targets for disease detection, monitoring and therapy.