An integrated genomic approach identifies follistatin as a target of the p63-epidermal growth factor receptor oncogenic network in head and neck squamous cell carcinoma

Differential gene expression profile in Porphyromonas gingivalis treated human gingival keratinocytes and their role in the development of HNSCC

Background

Periodontitis is considered to be one of the major risk factors associated with cancers of the oral cavity. Periodontogenic pathogens such as Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans are the important pathogens associated with periodontitis. Chronic exposure to bacterial components induces changes in the nearby cells. Hence, the present study has been designed to identify the molecular mechanisms that could be associated with the two disease conditions viz., periodontitis and head and neck cancer.

Objective

The present study investigated the differential gene expression profile in human gingival keratinocytes treated with P. gingivalis (Pg), a bacterium associated with periodontal disease, and its possible association with the development of Head and Neck Squamous Cell Carcinoma (HNSCC).

Methods

The study followed a computational design. Multiple tools and databases, such as GEOmnibus, STRING, Metascape, PANTHER, and UALCAN, cBioportal, were used to derive an association between gene expression during infection with P. gingivalis, and the resulting gene expression profiles were analyzed in the HNSCC dataset.

Results

The study revealed 29 genes from a pool of transcripts acquired after comparing the Pg-HIGK and Sham-HIGK. Among them, 3 genes i.e., FST, VRK3, and SGK1, were found to be overexpressed and significantly influenced patient survival. The upregulation of FST was found to correlate with poor prognosis in HNSCC patients.

Conclusion

The study provided insights into the possible association of FST, VRK3 and SGK1 in the development of HNSCC. Further investigations are warranted to confirm the functional role of these genes in establishing the cancer phenotype in patients with chronic infection with Pg.

Crosstalk between paralogs and isoforms influences p63-dependent regulatory element activity

The p53 family of transcription factors (p53, p63 and p73) regulate diverse organismal processes including tumor suppression, maintenance of genome integrity and the development of skin and limbs. Crosstalk between transcription factors with highly similar DNA binding profiles, like those in the p53 family, can dramatically alter gene regulation. While p53 is primarily associated with transcriptional activation, p63 mediates both activation and repression. The specific mechanisms controlling p63-dependent gene regulatory activity are not well understood. Here, we use massively parallel reporter assays (MPRA) to investigate how local DNA sequence context influences p63-dependent transcriptional activity. Most regulatory elements with a p63 response element motif (p63RE) activate transcription, although binding of the p63 paralog, p53, drives a substantial proportion of that activity. p63RE sequence content and co-enrichment with other known activating and repressing transcription factors, including lineage-specific factors, correlates with differential p63RE-mediated activities. p63 isoforms dramatically alter transcriptional behavior, primarily shifting inactive regulatory elements towards high p63-dependent activity. Our analysis provides novel insight into how local sequence and cellular context influences p63-dependent behaviors and highlights the key, yet still understudied, role of transcription factor paralogs and isoforms in controlling gene regulatory element activity.

The Reign of Follistatin in Tumors and Their Microenvironment: Implications for Drug Resistance

Follistatin (FST) is a potent neutralizer of the transforming growth factor-β superfamily and is associated with normal cellular programs and various hallmarks of cancer, such as proliferation, migration, angiogenesis, and immune evasion. The aberrant expression of FST by solid tumors is a well-documented observation, yet how FST influences tumor progression and therapy response remains unclear. The recent surge in omics data has revealed new insights into the molecular foundation underpinning tumor heterogeneity and its microenvironment, offering novel precision medicine-based opportunities to combat cancer. In this review, we discuss these recent FST-centric studies, thereby offering an updated perspective on the protean role of FST isoforms in shaping the complex cellular ecosystem of tumors and in mediating drug resistance.