Question

Matthew Bennett is a 32-year-old married salesperson who has been referred to an oncology clinic after a diagnosis of stage IIIA Hodgkin's disease was confirmed by his primary physician. Mr. Bennett first went to his physician after finding a lump in his right axilla that persisted for several months. The oncologist has recommended a program of chemotherapy that includes the following drugs: mechlorethamine (Mustargen) vincristine (Oncovin) prednisone (Deltasone) procarbazine (Matulane) 1. How is each drug classified as a chemotherapeutic agent, and what is its effect on the cell cycle?

Answer 1

The normal cells are divided by means of cell division. Same like the cancer cells undergoes cell division but uncontrolled way. The cell division of cancer cells occurs through the cell cycle. The process of cell cycle through the resting phase to active growing phase and then mitotic phase. Then DNA or RNA is main targets of chemotherapeutic agents which affect RNA or DNA. Because DNA or RNA are responsible for passing information of copying to cell. Thereby the death of cell is occur If the chemotherapy agent acts on the cell while the dividing of the cell, then it is called cell specific. If the anticancer drug acts on the cell when cells are in rest, then it is called cell non specific, it action on the cell is higher, thereby cell death occurs. Patient is receiving chemotherapy on the basis of type of cells, rate of dividing cells, and time of the effective treatment

PHASES OF CELL CYCLE

The cell cycle has 4 stages namely gap 1 and synthesis, gap 2 and mitosis. A cell undergoes all phases and its grows and divides. Interphase is called when a cell undergoes gap 1 and synthesis and gap 2.

GO phase: it is phase of cell rest while some cells are continuously dividing, some cells are take rest. It is the stage some cell leave the G1 and enter GO and doing its function without involving in division.

In gap 1 phase: size of the cell increase and its contents duplicated. in this phase RNA and protein synthesis take place

Synthesis phase: in this phase DNA replication occurs and its 23 pairs get copied by the cell. in this phase DNA synthesis take place

GAP 2 phase: growth of cells occurs and development of organelle and protein for the preparation of the cell division. in this phase mitotic spindle formation and completion of DNA synthesis take place

M phase: in this phase, cell division occurs and separation occurs and developmental of two identical daughter cells

chemotherapeutic drus are classified on the basis of chemical and mechanism of action.

Alkylating agents: alkylating agents can be categorized into the mustard gas derivative, ethylenimines, alkysulfonates, hydrazine and triazines, nitrosureas, metal salts

1. Mechlorethamine is classified as alkylating agents and it acts on cell nonspecifically that is resting phase of cell cycle and its acts DNA and change the structure of DNA after change the DNA. There by it break the DNA molecule and its strands. It can be administrated as a part of treatment of nonhodgkins lymphoma and Hodgkin’s lymphoma. It is derivatives of mustard gas

2. Vincristine is anticancer drugs and can be classified as plant alkaloid. Plant alkaloid is derived from plants. It can be given as a combination treatment to Hodgkin’s and Non Hodgkin’s lymphoma. It acts on the cell cycle specific that is M – Phase. It prevents formation micro tubular formation in the cell and prevents DNA and protein synthesis. That leads to cell death. Because microtubule is essential for dividing and replicating

3. Prednisone is classified as glucocorticocoid. It is used in the treatment of cancer. It inhibits the white blood cells from travelling to swelling area. Thereby it reduces the swelling around the tumor that results in reduction of pressure of tumor on nerve endings and get relieve from pain

4. Procarbazine is classified as alkylating agents and its action on the cell is nonspecific. It acts on the resting phase of cell cycle. it change the structure of the DNA by acting on DNA after altering code of DNA, results break of DNA molecule and its strands.

esting phase of cell are dangerous cell therefore resting phase of cell must be destroyed because of future proliferation.thereby repeated chemotherapy is administered to the patient in order to destroy the resting phase of cells