Introduction to Cancer Biology
Chemotherapy
1. Alkylating Agents: These drugs work by directly damaging DNA, preventing the
cancer cell from dividing. They are effective in treating various cancers, including
leukemia and lymphomas.
• 2. Antimetabolites: These mimic the building
blocks of DNA and RNA, disrupting the
synthesis of nucleic acids and inhibiting cell
division. They are often used to treat cancers
like breast, lung, and colorectal cancer.
• 3. Plant Alkaloids:
Derived from
plants, these drugs
inhibit the
formation of the
mitotic spindle,
preventing cells
from dividing
during the mitosis
phase. They are
commonly used in
treating leukemia,
lymphomas, and
breast cancer.
•
4. Topoisomerase Inhibitors: These drugs interfere with
the enzyme topoisomerase, which is essential for DNA
replication. By inhibiting this enzyme, these drugs
prevent cancer cells from dividing. They are often used in
treating ovarian and lung cancers.
5. Antibiotics
• Bleomycin binds to DNA within a cell and cuts the strands, a little
like the topoisomerase inhibitors, which eventually leads to the cell
dying.
• Dactinomycin inserts itself between the two strands of DNA and
holds them together, stopping the strands from being separated
and copied.
• Mitomycin creates bonds between DNA strands, like the alkylating
agents, but is more often used for adult cancers.
• Anthracyclines are a group of antibiotics that are used for a range of
cancers. They do a number of things that harm cancer cells,
including inserting itself into DNA to stop the strands being copied
and causing damage to DNA. They also stop DNA errors from being
repaired and change how the cells can absorb nutrients.
•
6. Targeted Therapies: Unlike traditional
chemotherapy, targeted therapies aim at
specific molecular targets associated with
cancer. These drugs work by interfering with
the cancer cell's growth and spread, making
them a more precise option for treatment
Antibodies
Target specific antigen
Specificity is relative
Various mechanisms of action
Complement activation
antibody-dependent cell-mediated cytotoxicity ADCC
Calcium entry
May synergize with chemotherapy
Expected or unexpected toxicities
Direct tumor cell killing by antibodies
This event may be triggered by antibodies binding to a tumor cell surface receptor, leading to its activation and,
consequently, apoptosis. Finally, an antibody may bind to an enzyme, leading to signaling abrogation, neutralization and cell
death. Conjugated antibody therapies are based around delivering a payload – for example, a drug, toxin, small interfering
RNA or radioisotope – to a tumor cell.
https://www.sciencedirect.com/science/article/pii/S2214647415000215#f0010
Small molecules Target oncogene product
Inhibit signaling at key steps
Safer than chemotherapy
Specific side effects
Specificity is often relative
Side Effects of Cancer Treatment
• Gastrointestinal tract
• Bone marrow
• Hair and skin
• Reproductive tract
Laser capture microdissection
Pharmacogenomics: drug therapies
tailored to individuals
• Design therapies based on the individual’s genome
• Subtle, but important, differences in genomes
- Linked to differences in how one responds to
drugs
• Identify those who will suffer harmful side effects from
particular drugs and who will respond best
• Customized therapy or personalized medicine
Pharmacogenomics
Pharmacogenomics
Remove
Pharmacogenomics
Summary
➟ Cancer cells proliferate defying normal controls; invades and colonize surrounding tissues
(malignant); gives rise to secondary tumors, or metastases; harder to eradicate surgically.
➟ mutations have important role in cancer.
➟ phenomenon of tumor progression, takes many years
➟ It is mainly disturbance of balance between cell division (mitosis) and cell death (apoptosis)
➟ Thus many factors contribute to the development of cancer, and since some factors are
avoidable features of environment, a large proportion of cancers are in principle preventable.
➟ To cure the disease requires an understanding of the special properties of cancer cells that
enable them to evolve, multiply, and spread.
➟ Drugs for differentiation/ program cell death are good approaches.
➟ To become malignant, tumor cells must cross basal laminae; antibodies can be designed that
interfere with this ability. Drugs can be designed to maintain function of suppressor genes.
➟ Cancer cells develop resistance to anticancer drugs. Suitably designed therapeutic attack
required. Combinatorial treatment.
Today: We learnt basic introduction about Cancer staging and some therapy
Assignment: What are the measures can be taken to prevent cancer
