Background:
Esophageal cancer (EC) is the 14th most common and the 8th most lethal cancer worldwide. It is subdivided into two main histological subtypes: esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC), both very lethal and often diagnosed at advanced stages, limiting treatment options. Understanding the molecular and cellular mechanisms involved in its genesis and progression is important for the identification of potential molecular markers for early diagnosis and possible therapeutic targets. For this, HMGA (High Mobility Group A) proteins are an interesting target of study. They are non histonic nuclear proteins, which regulate gene expression and play crucial roles in various cellular processes, are naturally overexpressed at the embryonic period. Adult tissues show little or no expression of HMGA proteins, but they are overexpressed in several human tumors and correlated with poor prognosis. Our group has shown that HMGA2 is overexpressed in ESCC, while HMGA1 is induced in EAC, and this fact is associated with the progression of both tumors. We have also demonstrated that silencing HMGA1 and HMGA2 in vitro, the malignant tumor phenotype can be reversed, highlighting their potential as therapeutic targets.
 
Objectives:
In this study, we are investigating the role of HMGA1 and HMGA2 in the neoplastic transformation of esophageal epithelial cells to better understand their involvement in esophageal carcinogenesis.
 
Methods:
We have used retroviral transduction to generate esophagus epithelial cell lines (HET-1A and EPC-hTERT) overexpressing HMGA1 and HMGA2. mRNA and protein levels of HMGA genes and targets will be assessed by RT-qPCR and Western blotting at 1, 15, 30, and 60 days. Functional assays (viability, proliferation, cell cycle, migration, invasion, and colony formation) will be performed at the same time points to characterize the resulting phenotypes.
 
Results:
The first half of the project, which includes the molecular biology procedures, has been completed. We have successfully cloned the HMGA1 and HMGA2 genes individually into the pQCXIP retroviral vector. Retroviral production was performed in the Phoenix Ampho cell line, yielding sufficient viral titers to transduce normal esophagus cell lines. We have successfully established the cell lines. Currently, we are evaluating the mRNA and protein expression levels of HMGA1 and HMGA2, as well as their target genes involved in carcinogenesis.
 
Conclusions:
In conclusion, we have successfully generated the target cell lines. We are currently evaluating HMGA expression at both the mRNA and protein levels, and our next step will be to investigate the cellular phenotypes. We anticipate that these data will provide valuable insights into the role of HMGA proteins in esophageal cell transformation.