Detection of Helicobacter pylori in paraffin-embedded formalin fixed liver tissue of patients with hepatocelular carcinoma

Abstract

Hepatocelullar carcinoma (HCC) is one of the most common diseases in the human population and results in between 250.000 and one million deaths annually. Researchers have described the role of Helicobacter (H.) pylori in the development of HCC. H. pylori is a bacterium that colonizes the human gastric mucosa and is considered as a type I carcinogen because of its association with gastric cancer and mucosa-associated lymphoid tissue lymphoma (MALT). Studies have identified H. pylori in bile, gallbladder and liver tissue samples of patients with chronic cholecystitis, primary sclerosing cholangitis, chronic hepatitis, cirrhosis and HCC. Due to these results and considering that HCC is an important public health problem all over the world, the aim of this study is detecting, amplifying and sequencing the H. pylori DNA in liver samples of patients with HCC. For this, 45 paraffin-embedded formalin fixed liver tissue samples will be studied. They will be divided into two groups: Group A (GA), composed by 30 samples of hepatic tumoral and peritumoral liver tissue of patients with HCC and Group B (GB), composed by 15 hepatic liver tissue samples without malignancy (control group). The samples will be amplified using polimerase chain reaction in two steps. In the first one, samples will be amplified with a Helicobacter genus-specific 16SrRNA pair of primers. The amplicons generated in the first step will be analysed in a second step with specific primers to H. pylori 26kDa gene. The sequence analysis of DNA will be done by using an ABI310 sequencer (Applied Biosystems). Data will be analysed by Qui-square and Fisher´s Exact Test considering the p-value d0.05 statistically significant. (AU)