# Common Molecular Mechanisms and Biomarkers in Breast, Colon and Ovarian Cancer
## 4 Discussion
The study of common molecular mechanisms in cancer has been addressed in previous research, suggesting the existence of shared pathways and proteins across different types of cancer. According to several prior studies, signaling pathways involved in cell cycle control, apoptosis, and DNA repair, such as the p53 pathway, are commonly altered in multiple cancer types [32]. The results of our study largely align with these observations, as PPI network analyses and KEGG pathway studies showed a prominent involvement of key proteins such as TP53, MSH2, and BRCA2, which are involved in DNA damage response and cell cycle regulation. Moreover, previous studies have highlighted the importance of shared biomarkers between these cancers, such as HER2 in breast cancer, which has also been implicated in colon cancer [33]. GO and KEGG analyses have shown that these processes are involved in a variety of cancer-related pathways, suggesting that alterations in these pathways could play a crucial role in the oncogenesis of multiple cancer types. In particular, proteins involved in DNA repair, such as MSH2 and BRCA2, could represent key therapeutic targets for the treatment of various cancers, not only in breast or colon cancer but also in ovarian cancer. The relationship between these proteins and pathways associated with infections, particularly viral ones, is especially noteworthy. The identification of MSH2 and KIT proteins as shared biomarkers suggests their potential utility in both diagnosis and prognosis across multiple cancer types, thereby enabling the development of broader targeted treatments. The results of this study open the door for further research in patient samples to confirm their applicability in clinical settings. The identification of proteins involved in multiple signaling pathways, such as the cell cycle and apoptosis, also opens up the possibility of using targeted therapies that could simultaneously affect several cancer types, optimizing resources and therapeutic approaches. The opposing expression patterns of MSH2 and KIT across breast, colon, and ovarian cancer may reflect distinct tumor regulatory mechanisms. MSH2, involved in DNA mismatch repair, plays a critical role in maintaining genomic stability, whereas KIT, a receptor tyrosine kinase, is involved in proliferative signaling. These differences suggest potential implications in treatment responses, particularly regarding therapies targeting genomic integrity and proliferative pathways. To ensure the reliability of the findings, data were exclusively obtained from curated databases. Additionally, an in-silico validation was performed using real patient data through the GEPIA platform, providing further evidence of the relevance of the identified biomarkers. While the importance of experimental validation is recognized, the results presented offer a solid foundation for future studies that could confirm their clinical applicability. Furthermore, this approach stands out for its simultaneous integration of data from breast, colon, and ovarian cancer, enabling a comprehensive comparison of shared molecular mechanisms and presenting a novel perspective on the search for common biomarkers. Although the results obtained in this study provide validation based on patient samples, it is essential to conduct additional experimental studies with clinical samples from other cohorts of patients with the three cancer types to validate the proteins identified as common biomarkers. Expression analysis in human tumors and preclinical models could provide a deeper understanding of their clinical relevance. The identification of key proteins involved in the oncogenesis of multiple cancers suggests that targeted therapies could be a viable option. Designing inhibitors for these common proteins could offer a way to treat several cancer types simultaneously. Identifying interactions between common proteins may shed light on the underlying signaling network in these cancer types.