Exam 1 Ch 54 Cancer Basic Principles

Question 1

Which oncogenes code for growth factor receptors?

Answer 1

HER2 and RET

Question 2

K-RAS and N-RAS are ongenes for cytoplasmic relays in stimulatory signaling pathways. What are their functions?

Answer 2

They code for guanine nucleotide-proteins with GTPase activity

Question 3

What is the function of the oncogene BCR-ABL?

Answer 3

A gene for cytoplasmic kinases

-codes for non-receptor tyrosine kinases

Question 4

What are 2 oncogenes for transcription factors that activate growth-promoting genes?

Answer 4

c-MYC and N-MYC

Question 5

What are the three genes for proteins in the cytoplasm?

Answer 5

APC-step in signaling pathway
NF-1- codes for protein that inhibits stimulatory Ras protein
NF-2- codes for protein that inhibits stimulatory Ras protein

Question 6

What oncogene can halt cell division and induce apoptosis?

Answer 6

p53

Question 7

What oncogene is the master brake for the cell cycle?

Answer 7

RB1

Question 8

Cells of ________ show diminished control of growth, BUT ___________ local tissue or spread to other parts of the body.

From Cancer Intro Lecture

Answer 8

Cells of Benign Tumors show diminished control of growth, BUT do NOT invade local tissue or spread to other parts of the body.

Question 9

What are the 7 Key Characteristics of Cancer cells?

From Cancer Intro Lecture

Answer 9

1) Proliferate rapidly
2) Diminished growth control
3) Self-sufficient in growth signals
4) Insensitive to anti-growth signals
5) Stimulate local angiogenesis
6) Often able to evade apoptosis
7) Invade local tissues & Spread/metastasize to other parts of body

Question 10

What is Desmoplasia?

From Cancer Intro Lecture

Answer 10

Dense collagenous stromal response often induced by malignant neoplasms, especially carcinomas (epithelial malignancies)

Question 11

What is cancer?

From Cancer Intro Lecture

Answer 11

Malignant Neoplasm
Out of control growth of abnormal cells
Cancer cells grow, rapidly divide and do not die in an orderly fashion

Question 12

What is Neoplasm?

From Cancer Intro Lecture

Answer 12

New Growth
Any abnormal new growth of tissue
Benign and malignant

Question 13

The two main components of a malignant tumor are cancer cells and stroma. What are the components of stroma?

Answer 13

Connective tissue and blood vessels. All connective tissue consists of three main components: fibers (elastic and collagenous), ground substance and cells (fibroblasts, adipocytes, immune cells (macrophages, mast cells, leukocytes))

Question 14

What are the morphological alterations seen in cancer cells?

Answer 14

• variation in size and shape of cells and their nuclei
• hyperchromatic nuclei due to increased DNA
• increased nuclear to cytoplasmic ratio
• large, irregular and/or multiple nuclei in neoplastic cells
• atypical, increased, and/or aberrant mitotic activity
• tumor giant cells
• disorganized tissue architecture
• ischemic necrosis

Question 15

What is the difference between a low grade and high grade cancer?

Answer 15

A low grade cancer cancer contains cells that are well differentiated (less aggressive, better prognosis), whereas a high grade cancer has poorly differentiated cells (more aggressive, worst prognosis)

Question 16

Describe the use of cancer staging, the TNM staging system, and state whether all cancers follow this.

Answer 16

Cancer staging reflects the amount and location of cancer in the body (extend and spread)
The TNM system describes Tumor size, lymph Node enlargement, and hematogenous Metastases.
Each cancer has its own staging system. For many cancers, the TNM combinations are grouped into five less-detailed stages (0-IV).

Question 17

List the three types of cancer nomenclature based on origin discussed in lecture, and how these different types of cancer differ.

Answer 17

1. Carcinoma: epithelial; most common type; arises from cell that cover external and internal body surfaces (e.g. breast, lung, colon)
2. Sarcoma: mesenchymal; arise from cells found in supporting tissue (e.g. bone, muscles, cartilage)
3. Lymphoma: lymph nodes and immune system
   These types of cancer differ in genetics, growth rate, and response to therapy

Question 18

Which enzymes discussed in lecture are involved in epigenetic modification that target anticancer agents, and what modifications do they carry out?

Answer 18

DNA methyltransferase methylates DNA at CpG dinucleotides, and histone deacetylases (HDACs) repress transcription. Anticancer agents inhibit these genes and target their modifications. E.g. hypermethylation at CpG dinucleotides found near tumor suppressor genes can switch off these genes promote cancer development.

Question 19

What are the two basic mechanisms through which chemopreventive agents work?

Answer 19

1. By inhibiting steps leading to cancer

2. By increasing protective processes