antineoplastic agents

• - dominant gain of function ie, amplification, translocation and mutation
•   
• - recessive loss of function, ie, Rb and p53

regulation circuits that govern normal cell proliferation and homeostasis

eliminating and destroying neoplastic cells

nausea, vomiting, fatigue, anemia, immunosuppression, leucopenia, alopecia, oral mucositis

Interact with DNA causing substitution reactions, cross-linking reactions or strand breaks.

Forming alky radicals, which form covalent linkages with nucleophilic moieties such as the phosphate, sulfhydryl, hydroxyl, carboxyl, amino, and imidazole groups.

purine precursor for treatment of metastatic melanoma, Hodgkin’s disease

it reacts directly with sulfur groups (such as glutathion), cross-links in DNA

Cytotoxic effects via similarity in structure or function to naturally occurring metabolites involved in nucleic acid synthesis -either inhibit enzymes involved in nucleic acid synthesis or produce incorrect codes

dihydrofolate raductase inhibitor

specific for S phase by interfering with DNA synthesis

streptomyces species

cytotoxic properties - by binding with DNA to produce irreversible complexes that inhibit cell division

The drug intercalates into DNA between adjacent guanine-cytosine base pairs and inhibits DNA-directed RNA synthesis.

The drug combines with DNA in an intercalative mode by slipping into the helical structure between stacked base. Therefore, biosynthesis of macromolecular and replication are inhibited.

•   * Also inhibits the progression of the
• enzyme topoisomerase to unwind DNA for transcription.

•    * For treatment of wide spectrum of solid
• tumors.

The cytotoxic action of bleomycin has been attributed to DNA scission and fragmentation with inhibition of the usual DNA repair mechanisms.

  Bleomycin is cell phase specific: major effects on G2 and M phases of the cell cycle. For treatment of Hodgkin’s and non-Hodgkin’s lymphomas, squamous cell carcinoma.

• it reacts with DNA in the manner of the alkylating agents. Binding to DNA leads to
• cross-linking and inhibition of RNA synthesis.

In combination with other antitumor drugs for the treatment  a number of solid tumors.

antimicrotubule agents

• MofA: The vinca alkaloids has been attributed to their capacity to arrest cell division in metaphase by binding to the microtubular protein (tubulin) that forms the
• mitotic spindle. 

For treatment of several types of cancer including leukemia, lymphoma, melanoma   and breast cancers

• Disrupt equilibrium between free
• tubulin and microtubules causing stabilization of cytoplasmic microtubules and thereby inhibits depolymerization. Subsequently, disrupts the normal dynamic reorganization of the microtuble network required for mitosis.

For the treatment of breast & ovarian cancers

Use agent with different cell cycle specificity, mechanisms of actions, toxicities, and potential combination for synergy.

Administer the drugs intermittent courses and at maximal tolerated doses to maximize cell kill, allow for host recovery, and avoid prolonged drug-free intervals.

Alternating non-cross-resistant regimen: ABVD and MOPP 

alternating the 2 regiment monthly or combine the 2 regimen into a monthly cycle

radiotherapy

bone marrow transplantation or peripheral stem cell reinfusion to rescue the host from total marrow aplasia

Tobacco

HPV infection (relate to p53, RB and E7)

chewing quids of betel

Alcohol Radiation exposure

Long-term irritation caused by ill-fitting dentures (inflammation lead to oncogenesis)

Surgery

Radiation therapy

• Chemotherapy
• Cisplatin, 5- Fluorouracil, carboplatin, paclitaxel

Tumor growth factors: tageting EGFR

EGFR antibodies and tyrosine kinase inhibitors

• Oral mucositis
• salivary gland dysfunction
• neurotoxicity: taste dysfunction, dentinal hypersensitivity
• temporomandibular dysfunction
• dental and skeletal growth and 
• developmental anomalies (pediatric patient)