BRCA1 gene
- Name: BReast CAncer gene 1
- Type of gene: Tumour suppressor gene responsible for repairing DNA located on chromosome 17.
- Associated cancers: Individuals who have a BRCA1 gene mutation are at an increased risk of breast, ovarian, pancreatic, cervical, uterine and colon cancers. BRCA1 mutations are also associated with an increased risk of triple-negative breast cancer.
- Interesting research: It is likely that breast cancer develops similarly in men and women, as frequencies of BRCA1 and BRCA2 have remained the same in both sexes. This suggests that advances in treatment for the disease may benefit all patients, irrespective of gender.
BRCA2 gene
- Name: BReast CAncer gene 2
- Type of gene: Tumour suppressor gene responsible for repairing DNA located on chromosome 13.
- Associated cancers: Individuals who have a BRCA2 gene mutation are at an increased risk of breast, ovarian, pancreatic, gallbladder, bile duct and melanoma cancers.
- Interesting research: The Gly3076Val mutation of the BRAC2 gene has been found to be a pathogenic variant. This alteration results in a substitution of glycine 3076 withing the DNA binding domain. This information can now be used to identify predisposed family members and guide early detection strategies.
APC gene
- Name: Adenomatous Polyposis Coli
- Type of gene: Tumour suppressor gene
- Associated cancers: Mutations in the APC gene are associated with familial adenomatous polyposis (FAP). This condition is commonly linked to the formation of polyps in the colon that can become cancerous. Alterations of the APC gene are also responsible for a disorder called Turcot syndrome. This condition is also associated with polyps in the colon and linked to primary brain tumour.
- Interesting research: The immune microenvironment landscape of colon cancer has now been illustrated, allowing researchers to gain further insight into the role of chronic inflammation in the disease and determine its potential use as a prognostic factor.
ATM gene
- Name: Ataxia-Telangiectasia Mutated
- Type of gene: Protein coding gene
- Associated cancers: Mutations in the ATM gene cause Ataxia-telangiectasia (A-T), which is a condition characterised by progressive neurological problems that eventually lead to difficulty with walking. People with A-T have a high risk of developing cancer, most commonly leukaemia and lymphoma. It is also associated with an increased risk of developing breast cancer, ovarian cancer, stomach cancer, melanoma and sarcoma. Moreover, mutations in the ATM gene have been associated with mantle cell lymphoma.
- Interesting research: The treatment approach for children with A-T is extremely difficult due to children’s extreme sensitivity to chemotherapy. Therefore, therapeutic methods for A-T need to be refined with further research required to understand the heterozygosity of the ATM gene. This will help reduce the number of deaths in vulnerable patients caused by the disease.
RAS gene family
- Name: RAt Sarcoma virus
- Type of gene: Guanosine-nucleotide-binding protein coding gene.Members of the RAS gene family includeH-ras, N-ras or K-ras.
- Associated cancers: Mutations ofRAS genescause alterations in the Ras-MAPK pathway, which regulates a variety of cellular functions that are important for tumourigenesis. RAS mutations are linked to pancreatic ductal adenocarcinoma, colorectal cancer, non-small cell lung cancer and haematopoietic malignancies.
- Interesting research: Scientists have identified three molecular subtypes of lung cancer in patients who have never smoked before, one of which was named ‘piano’. This was the dominant subtype and was characterised by frequent K-ras mutations.
TP53 gene
- Name: Tumour Protein 53
- Type of gene: Tumour suppressor gene
- Associated cancers: An inherited TP53 mutation causes Li-Fraumeni syndrome, which is an inherited predisposition to a wide range of rare cancers. Although, it is much more likely that the TP53 mutation is somatic – inherited alterations have been found in half of all cases of cancer. In fact, TP53 is the most commonly acquired mutation in cancer. Examples include breast cancer, bone cancer, leukaemia and sarcomas.
- Interesting research: A new single-cell single-molecule DNA sequencing method, called acoustic cell tagmentation, has revealed that triple-negative breast cancers undergo continued genetic copy number changes during tumour growth after clonal TP53 mutations. This insight is hoped to help explain why breast cancer treatments are not always effective.
RET gene
- Name: REarranged during Transfection
- Type of gene: Protein coding gene
- Associated cancers: Mutations in the RET gene can give rise to multiple endocrine neoplasia type 2 (MEN2). This is a hereditary cancer syndrome, which is characterised by the prevalence of medullary thyroid carcinoma and an increased risk of developing other tumours affecting the glands in the endocrine system. Moreover, gene fusions in the RET protein are linked to papillary thyroid carcinoma and non-small cell lung cancer.
- Interesting research: Extensive research on the role of kinase fusions in lung cancer has revealed that the RET gene is involved in driving oncogenesis and acting as an acquired resistance mechanism to kinase inhibitors. Interestingly, stage 5 adenocarcinoma patients, with a particular RET fusion (AFF2-RET), have demonstrated favourable clinical outcomes on tyrosine kinase inhibitor drugs.
BRAF gene
- Name: 94 kDa B-Raf Protein
- Type of gene: Protein coding gene
- Associated cancers: Mutations to the BRAF gene cause alterations in the Ras-MAPK pathway, which regulates a variety of cellular functions that are important for tumourigenesis. BRAF mutations have frequently been found in melanoma, multiple myeloma, lung cancer, colorectal cancer, ovarian cancer and thyroid cancer.
- Interesting research: Through exploration of genomic sequencing data, the BRAF gene has been identified as a predictive biomarker for response to an FDA-approved drug for gliosarcoma, an aggressive brain tumour with features of glioblastoma and soft tissue sarcoma.
HER2 gene
- Name: Human Epidermal growth factor Receptor 2
- Type of gene: Protein coding gene
- Associated cancers: The HER2 gene encodes for HER2 proteins, which are found on the surface of breast cells and promote cell growth. Somatic mutations to the HER2 gene cause abnormal amounts of these cells to grow and divide, leading to tumour growth. Breast cancer cells with higher levels of HER2 are called ‘HER2-positive’ and can be targeted with drugs that supress the gene.
- Interesting research: Natural killer cells, called HER2 CAR-NK cells, have been engineered to target HER2-expressing cancer cells. Current results have shown that these cells have no unwanted cytotoxic effects or cytokine production against non-malignant cells, suggesting they could become a potent and safe form of immunotherapy against solid tumours.
PTEN gene
- Name: Phosphatase and TENsin homolog
- Type of gene: Tumour suppressor gene, which encodes for the PTEN phosphatase enzyme.
- Associated cancers: Many PTEN mutations have been identified that cause Cowden and Cowden-like syndrome. These conditions are characterised by both several hamartomas and an increased risk of developing certain cancers, particularly breast cancer, thyroid cancer and endometrial cancer. Moreover, PTEN has been reported to be the most frequently mutated gene in prostate cancer. PTEN gene mutations are also commonly found in glioblastomas, astrocytomas and melanoma.
- Interesting research: Researchers recently documentedthe first case of a fibroadenoma developing in ectopic breast tissue of the vulva in a patient with a germline pathogenic variant in the PTEN gene. Fibroadenomas are common non-cancerous breast tumours. This highlights the risk of hyperplasia (an increase in cell number) developing in any breast tissue at any location, particularly in patients with variants in cancer susceptibility genes.
Cancer Genomics: From Diagnosis to Treatment
Image credit: Healthline
