Genome-Editing Advancements in Understanding and Treating Hereditary Cancers

Genome-Editing Advancements in Understanding and Treating Hereditary Cancers

Sub :Sci

Sec: Biotech

Why in News

Advances in CRISPR-based genome-editing techniques are improving the understanding of hereditary cancers, including how certain genetic mutations affect cancer development and resistance to targeted therapies. These breakthroughs offer promising new avenues for cancer treatment and personalized medicine.

Global Cancer Statistics:

According to the International Agency for Research on Cancer, an estimated 20 million new cancer cases and 9.74 million cancer-related deaths occurred in 2022, projected to rise to 32 million new cases and 16 million deaths by 2045. Asia may account for almost half of the global cancer burden by 2045.

Around 10% of cancer cases are caused by inherited genetic mutations. The prevalence is notably high in certain cancers, such as ovarian cancer (20% of cases), and lower in cervical cancer (6%).

Hereditary Cancer: Occurs when an individual inherits mutations in cancer-causing genes. BRCA1 and BRCA2 mutations are the most well-studied, causing Hereditary Breast and Ovarian Cancer (HBOC).

The BRCA gene (BRCA stands for BReast CAncer gene) refers to two genes, BRCA1 and BRCA2, which play a crucial role in suppressing tumors by repairing DNA damage. Mutations in these genes can impair their ability to repair DNA, leading to an increased risk of several cancers, particularly breast and ovarian cancers.

Germline Mutations: These mutations predispose individuals to multiple cancers, including breast, ovarian, prostate, pancreatic, and gastric cancers.

Women with BRCA mutations face a 69-72% risk of breast cancer and a 17-44% risk of ovarian cancer by age 80. This is significantly higher compared to the general population’s lifetime risks of 12% for breast cancer and 1% for ovarian cancer.

Preventive Measures: Options like prophylactic mastectomy and oophorectomy can reduce the risk of developing cancer by 90-100% and significantly lower cancer-related deaths.

Genetic bottlenecks and founder effects contribute to the higher prevalence of BRCA mutations in certain populations.

Genome Editing and Personalized Cancer Therapy:

Testing for BRCA mutations helps in early identification of cancer risk, leading to personalized prevention strategies, such as increased surveillance and targeted therapies.

CRISPR in Cancer Research: It has revolutionized cancer research by allowing scientists to create specific mutations in BRCA genes, helping to better understand their role in DNA repair and cancer development.

What is CRISPR-Cas9?

CRISPR is a dynamic, versatile tool that allows us to target nearly any genomic location and potentially repair broken genes.

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) are sections of DNA and are sections of genetic code containing short repetitions of base sequences followed by spacer DNA segments.

CAS-9 (CRISPR-associated protein 9) is an enzyme. It uses a synthetic guide RNA to introduce a double strand break at a specific location within a strand of DNA. It is a system used by bacterial cells to recognize and destroy viral DNA as a form of adaptive immunity.

Targeted Therapies: PARP inhibitors, a new class of chemotherapy drugs, show promise in treating cancers caused by BRCA mutations. Clinical trials reveal their effectiveness, especially when combined with platinum-based chemotherapy.

Genome-wide CRISPR screens have identified mutations in other DNA repair genes that may affect the response to PARP inhibitors, providing insights into why some patients resist these treatments.

About Cancer:

Cancer is a disease characterized by the uncontrolled growth and spread of abnormal cells within the body. It can arise in various tissues and organs, leading to the formation of tumours.

Cancer begins with genetic mutations that alter the normal behaviour of cells. These mutations can result in the proliferation of cancerous cells, forming clusters known as tumours.

The cancerous cells may detach from these tumours and spread through the lymphatic system or bloodstream, leading to metastasis in other body regions.

Approximately 63% of all deaths in India are attributed to NCDs, with cancer being a significant contributor.

By 2030, the economic burden of cancer-related illnesses is projected to reach approximately $3.55 trillion in lost output.