FINAL EXAM part 6 - Neoplasia

Question 1

Malignant tumor cells characteristic:

Answer 1

• Undifferentiated cell
• Do not look like their tissue of origin
• Heterogeneous (change, diverse–> difficult to tx)
• Loss of normal feature
• Pleomorphic (multiple shapes and sizes)
• Little evidence of normal function
• Can spread (metastasis) and produce new blood vessels into the tumor (angiogenesis)

Question 2

Systemic effects of malignant tumors:

Answer 2

Cachexia (total body wasting)

• Paraneoplastic syndromes (biochemical, neurological, hematoligical derangements caused by abnormal compounds that tumors can release)
• Immunosuppression (more susceptible to infections)

Question 3

Histological grading of tumors with the:

Answer 3

Gleason Scale:
Grade I (well differentiated)
Grade II (moderately differentiated): increase mitoses and variation in size and shape.
Grade III and IV (poorly differentiated)

Question 4

Cancer cell at the beginning:

Answer 4

• Initial cancer cell has to multiply about 30 doublings before you have the smallest detectable tumour mass.
• Because of the exponential phenomenon, it only take 10 more doublings before you are dead.

Question 5

Proto-oncogenes are:

Answer 5

Genes that are involved in normal cell growth

Question 6

3 differents ways Proto-oncogenes can be altered:

Answer 6

1. Gene amplifications: more receptors –> more growth
2. Translocation/transposition: relocation of a gene that is now next to a new promoter which increase production of a protein –> stimulate growth
3. Point mutation: too much of a normal growth-stimulating protein or an abnormal hyperactive or degradation resistant protein –> hyperactive growth and act for a long period

Question 7

Burkitt lymphoma

Answer 7

Burkitt lymphoma is caused by Epstein Bass Virus (EBV/HHV4) (B lymphocytes) combined with malaria

Question 8

Cancer cells are able to resist cell death because of

Answer 8

The BCL-2 is overexpress–>block apoptosis by blocking the normal signaling mechanisms

Question 9

RB Gene (Governor of the Cell Cycle) is:

Answer 9

• The RB genes codes for a protein that suppresses cell growth.
• It attaches to the transcription factor that binds DNA to block transcription.

Question 10

P-53 Gene (Guardian of the Genome) is:

Answer 10

• A sensor of multiple forms of stress (DNA damage, activated oncogenes, hypoxia, RNA depletion, telomere erosion) –> Major defenses against cancer
• P53 will either cause the cell to die by triggering apoptosis or it will stop cell division to try to allow the cell to fix itself.

Question 11

Colorectal cancer development:

Answer 11

Adenomatous polyp–> clonal expansion

Question 12

Familial adenomatous polyposis (FAP) is

Answer 12

• Born with one abnormal APC gene which causes thousands of polyps throughout the GI tract. (will not take long before getting a second defective enzyme)
• APC regulates B catenin (needed to regulate the cell growth)

Question 13

The majority of breast cancer is in origin:

Answer 13

Ductal

Question 14

Sentinel Lymph nodes are:

Answer 14

The lymph node that drains the area of the tumor

Question 15

One of the method for evaluating prognosis of breast cancer:

Answer 15

Is to see whether or not the tumor cell still has the normal receptors or not.

• If the estrogen receptors are still present, it gives physicians a way to tx the cancer with hormone blocking agents. (better prognosis)->Tamoxifen
• If the HER2 is overexpressd at the surface of the tumor cells (prognosis is grimmer)->MAB

Question 16

4 ways the tumor can resist the hormone therapy:

Answer 16

1. De novo androgenesis: it makes its own androgens
2. Overexpression of the androgen receptor: even tiny amount of androgens can keep it going
3. Non-specific ligand recognition: will start reponding to other ligands besides the androgen to stimulate its growth
4. Ligand independent activation: does not need androgens at all anymore, completely independent.

Question 17

Brachytherapy is;

Answer 17

radioactive units inserted aroung the region of the tumor cells is, release radiation and kill locally the cancer cells.

Question 18

HPV (human papillomavirus) can cause cervical cancer: mechanisms:

Answer 18

Viral protein inactivates RB and P53