Altered HOX and WNT7A expression in human lung cancer

Area of Science:

• Molecular Biology
• Genetics
• Oncology

Background:

• HOX genes are crucial for development and cell fate.
• HOX gene alterations are known in leukemia but their role in lung cancer is unclear.
• WNT pathway, including WNT7a, influences HOX expression and cell behavior.

Purpose of the Study:

• To investigate HOX gene expression patterns in lung cancer.
• To explore the relationship between HOX genes, WNT pathway, and fibroblast growth factor (FGF) signaling in lung cancer.
• To identify potential regulatory circuits involved in lung tumorigenesis.

Main Methods:

• Degenerate reverse transcription-polymerase chain reaction (RT-PCR) and real-time quantitative assays were used to examine HOX gene expression.
• Analysis included lung cancer cell lines, tumor-control pairs, and bronchial epithelial cultures.
• Gene expression and protein levels were correlated, and genetic alterations like deletions were investigated.

Main Results:

• HOX9 paralogous group genes and HOXA10 were frequently overexpressed in lung cancer.
• Elevated HOXB9 RNA correlated with protein overexpression.
• WNT7a was often reduced or absent in lung cancers, with loss correlating with HOXA1 expression.
• A homozygous deletion of beta-catenin was found in a mesothelioma cell line, linked to reduced WNT7a and HOX gene expression.

Conclusions:

• HOX gene dysregulation is common in lung cancer, similar to leukemia.
• Alterations in WNT signaling, particularly WNT7a loss, may contribute to lung tumorigenesis.
• The findings suggest complex interactions between HOX, WNT, and FGF pathways in lung cancer development.