Deck 52: Cancer Biology

Question 1

You are treating a 47-year-old woman who has come to you with complaints of fatigue, chronic headaches, and radiating pain and fullness on her left side. A routine blood test indicates the presence of increased immature white cells (blasts), reduced platelets, and reduced leukocytes. You order a cytogenetic analysis of the blasts and the results indicate the presence of a chromosomal abnormality consistent with a t(9:22) translocation. This patient is most likely suffering from which of the following?

A) acute lymphocytic leukemia, ALL
B) acute myelogenous leukemia, AML
C) chronic myelogenous leukemia, CML
D) Hodgkin lymphoma
E) Non-Hodgkin lymphoma, NHL

Answer 1

chronic myelogenous leukemia, CML

Question 2

You are treating a 37-year-old African-American man who has come to you complaining of abdominal distension, night sweats, and shortness of breath all of which have developed over the last 4 weeks. Physical examination decreased breath sounds in right lung base and a 2-cm lymph node appreciated on left inguinal region. Excision biopsy and culture of cells from the inguinal lymph node identified the presence of a chromosomal translocation between chromosomes 14 and 18. Your patient is most likely suffering from which of the following?

A) acute lymphocytic leukemia, ALL
B) acute myelogenous leukemia, AML
C) chronic myelogenous leukemia, CML
D) Hodgkin lymphoma
E) Non-Hodgkin lymphoma, NHL

Answer 2

Non-Hodgkin lymphoma, NHL

Question 3

A 27-year-old man is being examined by his physician to ascertain the cause of the bumps appearing on his skull and jaw. Close examination of the patient also shows epidermoid cysts, extra teeth, and freckle-like spots on the insides of his eyes. Family history indicates that his mother died of colorectal cancer when the patient was only 6 years old. Given the external signs apparent in this patient you recommend a colonoscopy which shows hundreds of polyps. Which of the following genes is most likely defective in this patient accounting for all of the observed symptoms?

A) APC
B) NF1
C) p53
D) RB
E) VHL

Answer 3

APC

Question 4

You are a genetic counselor discussing the results of a global genetic profile a 37-year-old woman had done through an online testing company. She is particularly concerned because the test flagged a mutation in a gene identified as PALB2. You inform her that mutations in this gene are highly correlated to a particular cancer. Which of the following is this cancer?

A) breast cancer
B) colorectal cancer
C) fibrosarcoma
D) lymphoma
E) retinoblastoma

Question 5

You are treating a 6-year-old girl who fell off her bike and broke her arm. She appears healthy in all other respects, however, during your examination you observe that she has several large and dark café-au-lait patches on her back and upper legs. As her physician you inform her parents that she may have inherited a mutated form of a gene called NF1. Which of the following would this child be most likely to experience as a result of a mutation in this gene?

A) breast cancer
B) colorectal cancer
C) lymphoma
D) neurofibroma
E) retinoblastoma

Question 6

You are treating a 26-year-old man who presented with exudative macular edema. Ocular and systemic studies revealed the presence of retinal and central nervous system hemangioblastomas, adrenal pheochromocytoma, as well as multiple pancreatic and renal cysts. Detailed family history revealed that his father had died from cerebral vascular accident at the age of 54 and had been treated for uncontrolled blood pressure, but was not investigated for possible presence of adrenal gland tumor. This patient is most likely suffering from defective function of which of the following genes?

A) APC
B) NF1
C) p53
D) RB
E) VHL

Question 7

A 57-year-old woman has come to her physician to determine if something is seriously wrong with her as she has been suffering from fatigue, chronic headaches, and radiating pain and fullness on her left side for the past 5 months. Her physician orders a routine blood test that indicates the presence of increased immature white cells (blasts) that also contain the Philadelphia chromosome. This leads to a diagnosis of chronic myelogenous leukemia, CML. CML results from this translocation due to abnormal regulation of which of the following genes?

A) ABL
B) MYC
C) p53
D) pRB
E) RAS

Question 8

Which of the following defines the term neoplasm?

A) any of the many cancers of the lymphatics or hematopoietic system
B) cells that generate invasive tumors when transplanted
C) malignant cells from carcinomas and sarcomas
D) results from the consequences of chromosomal translocations
E) tissue that grows in the absence of an initial growth-stimulating signal

Question 9

Which of the following defines the meaning of the term proto-oncogene?

A) always expressed in a normal cell
B) always transcription factors
C) always virally derived
D) never expressed in a normal cell
E) tightly regulated in a normal cell

Question 10

Which of the following familial cancers results from a defect in the tumor suppressor gene, p53?

A) familial adenomatous polyposis coli (FAP)
B) Li Fraumeni syndrome
C) neurofibromatosis type 1
D) retinoblastoma
E) Wilms tumor

Question 11

Analysis of a tumor cell line indicates that there is a dramatically increased level in the activity of the transcription factor E2F. Which of the following is the most likely explanation for this observation?

A) an increase in the expression of pRB resulting in increased binding of pRB to E2F
B) hypophosphorylation of pRB so that it can no longer interact with E2F
C) loss of expression of pRB which normally activates E2F
D) mutation in pRB that prevents its phosphorylation so that it cannot interact with the gene to which it normally binds and coactivates with E2F
E) mutation in the domain of pRB to which E2F binds, the consequences of which lead to constitutive E2F activity

Question 12

Numerous cancers are caused by a genetic phenomenon termed "loss of heterozygosity," LOH. This phenomenon led to the identification of genes termed tumor suppressors, because it is the loss of their function that leads to cancer. Which of the following has been shown to result from defects in a tumor suppressor gene as a consequence of LOH?

A) Creutzfeldt-Jakob disease
B) Crouzon syndrome
C) Huntington disease
D) Li-Fraumeni syndrome
E) Prader-Willi syndrome

Question 13

Mutant genes that affect several organ systems and bodily functions frequently show variable expressivity. A phenomenon referred to as phenotypic variation. The most striking example of phenotypic variability is manifest in an autosomal dominant condition characterized by the appearance of café au lait spots on the skin and cutaneous and subcutaneous neurofibromas. These symptoms are associated with which of the following?

A) familial adenomatous polyposis
B) familial hypercholesterolemia
C) Li Fraumeni syndrome
D) von Hippel-Lindau syndrome
E) von Recklinghausen disease (type I neurofibromatosis)

Question 14

A 29-year-old woman presents with weakness, fatigue, easy bruising, and nosebleeds. Analysis of her blood reveals a reciprocal translocation between chromosomes 22 and 9, and low leukocyte alkaline phosphatase levels. These findings confirm a diagnosis of which of the following?

A) acute lymphoblastic leukemia
B) Burkitt lymphoma
C) chronic myelogenous leukemia
D) follicular lymphoma
E) Hodgkin lymphoma

Question 15

Your patient is a 49-year-old woman who has experienced a 2-year history of recurrent burning chest pain. Your previously prescribed medications and antacids have provided her with minimal relief. No physical abnormalities are noted during this visit. You perform an upper endoscopy and take a biopsy specimen. Histological examination of the biopsy shows a microinvasive adenocarcinoma arising from intestinal metaplasia in the distal portion of the esophagus. The most likely cause of the loss of cohesion of the neoplastic epithelial cells in this lesion is a decrease in the expression of which of the following molecules?

A) E-cadherin
B) fibronectin
C) I-CAM
D) laminin
E) P-selectin

Question 16

You are studying the characteristics of a particular protein isolated from cells of a squamous cell carcinoma and comparing it to the same protein isolated from nonaffected cells from the same tissue. When grown in culture, the normal cells arrest in the G₀ phase of the cell cycle. Analysis of the 2 proteins demostrates that the normal protein binds to DNA, whereas, the mutated protein from the carcinoma cells does not. These findings are most characteristic of which of the following?

A) growth factor receptors
B) GTP-binding proteins
C) nonreceptor tyrosine kinases
D) oncogene proteins
E) tumor suppressor gene proteins

Question 17

Your current patient is a 49-year-old man. You just performed a partial hepatic resection to remove a solitary 7-cm mass that was discovered by ultrasound. Histological examination of the biopsied mass indicates hepatocellular carcinoma. Genetic analysis indicates a mutation of the p53 tumor suppressor gene in an area identified as a mutational "hot spot." Which of the following agents is the most likely carcinogen causing this patient's disease?

A) aflatoxin B1
B) Clonorchis sinensis
C) ethanol
D) hepatitis A virus
E) vinyl chloride

Question 18

Which of the following mechanisms characterizes the usual action of most oncogenes?

A) defective DNA repair
B) dominant negative
C) gain-of-function
D) haploinsufficiency
E) loss-of-function

Question 19

You are studying the responses of cultured intestinal epithelial cells to various types of ionizing radiation. The cells you are using contain a functional p53 gene. Following exposure to ultraviolet light, which of the following events is most likely to occur?

A) apoptosis is inhibited
B) cells are prevented from entering S phase
C) the concentration of p53 decreases
D) replication of DNA is enhanced
E) transcription of metaphase cyclins is increased

Question 20

A 27-year-old man has undergone a routine colonoscopy because of his concern over a family history of colon cancer. There is no family history of any other types of cancer. During the colonoscopy a single 2-cm polyp is seen and removed. Histological examination of the polyp shows a villous adenoma. Metaphase chromosomal spread shows microsatellite instability but no translocations or deletions. This patient has most likely inherited a defect that has led to interference in which of the following processes?

A) cell adhesion regulation
B) DNA mismatch repair
C) growth factor receptor expression
D) regulation of apoptosis
E) signal transduction

Question 21

A 38-year-old woman has had a biopsy taken from her cervix due to an abnormal Pap smear result. Histological analysis of the biopsy tissue shows grade 3 intraepithelial neoplasia. Additionally, the results demonstrate that the cancerous cells are widely dispersed. Altered expression of which of the following is the most likely cause of the dispersion of the neoplastic cells throughout the biopsy tissue?

A) cadherins
B) elastases
C) laminin receptors
D) matrix metalloproteinases
E) tissue inhibitors of metalloproteinases