5. Among the following which gene is not directly concerned with induction of cancer

(1) Src                                                 (2) Ras
(3) P₅₃                                                  (4) Actin

SEO Article: Which Gene is Not Directly Concerned with Induction of Cancer?

Cancer arises due to genetic alterations that disrupt normal cell growth and division. Among the many genes involved, some are known oncogenes or tumor suppressor genes that contribute directly to cancer development. However, not all genes expressed in cells have a role in inducing cancer. Understanding which genes are involved is crucial for cancer research, diagnosis, and therapy.

Genes Involved in Cancer Induction

1. Src Gene
   Src is one of the first discovered oncogenes. It encodes a tyrosine kinase that regulates signaling pathways involved in cell growth, differentiation, and survival. Mutations or overactivation of Src leads to uncontrolled cellular proliferation, promoting tumorigenesis.​

2. Ras Gene
   Ras is a well-known oncogene family that encodes small GTPase proteins involved in transmitting signals from cell surface receptors to the nucleus. When mutated, Ras proteins remain constitutively active, driving continuous cell proliferation and survival signals leading to cancer formation.​

3. P53 Gene
   P53 is a major tumor suppressor gene known as the “guardian of the genome.” It controls cell cycle arrest, DNA repair, and apoptosis in response to DNA damage. Loss of p53 function due to mutations removes these safety checks, allowing abnormal cells to survive, proliferate, and become cancerous.​

The Role of Actin

4. Actin
   Unlike Src, Ras, and p53, Actin is a structural protein that forms microfilaments, part of the cytoskeleton in all eukaryotic cells. It is crucial for cell shape, motility, and intracellular transport but does not directly regulate cell proliferation or tumor suppression. Therefore, Actin itself is not directly concerned with the induction of cancer, although changes in cytoskeleton dynamics can influence cancer cell behavior.​

Summary Table

Why Actin is Not Directly Involved

Actin’s core function lies in maintaining cell architecture and movement. Its deregulation may assist cancer progression by enabling metastasis but it is not a gene that induces cancer through mutation or direct control of proliferation. This distinguishes it from classical oncogenes and tumor suppressors, which act at the genetic and signaling levels to induce or suppress tumor formation.

Clinical Importance

Identifying genes directly concerned with cancer induction, such as Src, Ras, and p53, helps in:

• Developing targeted cancer therapies (e.g., kinase inhibitors for Src, Ras pathway inhibitors)

• Designing diagnostic tools that detect mutations in these genes

• Understanding mechanisms of drug resistance and tumor progression

Actin, while important for cancer cell motility, is not a primary target for cancer treatment related to oncogenic processes.

Final Answer

Among the options, the gene not directly concerned with induction of cancer is (4) Actin. Src, Ras, and p53 play direct roles in cancer development as oncogenes or tumor suppressors, whereas Actin is a cytoskeletal protein involved in cell structure and movement but does not directly induce cancer.