PHM 212 Tutorial Questions

Recent research suggests that specific microRNAs (miRNAs) can function as oncogenes or tumor suppressors depending on the cellular context. In the context of self-sufficiency in growth signals, how could miRNAs potentially contribute to this hallmark of cancer?

A 45-year-old woman presents with a rapidly growing mass in her breast. Biopsy reveals an ER/PR positive, HER2-negative breast cancer. Which of the following genetic alterations is LEAST likely to be driving the aggressive growth of this tumor?

A researcher is investigating the role of epigenetic modifications in cancer development. She observes increased methylation of the promoter region for a specific tumor suppressor gene in colorectal cancer cells. Hypermethylation of promoter regions typically leads to what consequence for gene expression?

A researcher is studying a novel anti-inflammatory drug that specifically targets a specific adhesion molecule on endothelial cells. This drug is most likely to be effective in inhibiting:

In an experiment with cultured human cells, researchers aimed to enhance the removal of free radicals. Which antioxidant enzyme would they most likely upregulate?

A 60-year-old patient presents with severe chest pain and elevated troponin levels, indicative of a myocardial infarction. Electron microscopy of myocardial cells shows extensive mitochondrial swelling and disrupted cristae. Which of the following best explains the underlying mechanism of the observed mitochondrial damage?

In a laboratory experiment with cultured endothelial cells, researchers use phorbol esters to activate protein kinase C (PKC). This activation led to the generation of free radicals. Which enzyme is most likely involved in this process?

A study on apoptotic signaling pathways shows that cleavage of poly (ADP-ribose) polymerase (PARP) is a hallmark of apoptosis. Which executioner caspase is most commonly associated with this cleavage?

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) relieve pain and inflammation by inhibiting the enzyme:

A researcher is studying the role of a specific chemokine receptor in neutrophil recruitment during bacterial infection. They create a mouse model with a genetic deletion of this receptor. Compared to wild-type mice, the knockout mice would most likely show:

During an experimental study, hepatocytes are exposed to carbon tetrachloride (CCl4). Which of the following best describes the primary mechanism of hepatocyte injury caused by CCl4?

Researchers investigate the role of a specific gene (X) in phagocytosis by isolating macrophages from wild-type and X-deficient mice. They expose both types of macrophages to bacteria and measure the rate of bacterial uptake. Macrophages lacking X exhibit significantly impaired phagocytosis compared to wild-type cells. Based on this experiment, what is the most likely function of gene X?

A 25-year-old woman presents with a red, swollen, and tender toe after dropping a heavy object on it. Microscopic examination of the affected tissue reveals extensive infiltration of neutrophils. Which of the following best describes the role of these neutrophils in this scenario?

A scientist is studying a rare syndrome characterized by delayed pus formation at sites of infection. They perform gene expression analysis on leukocytes from affected individuals and identify a downregulation of a specific gene involved in cytoskeletal rearrangement. Which of the following processes related to leukocyte recruitment is MOST likely to be impaired in this syndrome?

A clinical trial in Phase II is testing a drug that targets telomerase activity in cancer cells. What is the anticipated effect of inhibiting telomerase in these cells?

A study on human fibroblasts demonstrates that telomerase activity is significantly reduced in aged cells. What is the most likely consequence of this reduction?

Researchers are investigating a novel therapeutic approach for inflammatory bowel disease (IBD). They design a drug that specifically targets the interaction between integrin α4β7 and its ligand, MAdCAM-1, expressed on gut endothelial cells. How would this approach MOST likely affect leukocyte recruitment to the inflamed intestinal mucosa in IBD?

A 68-year-old female is part of a clinical trial testing a new intervention aimed at reducing the effects of cellular senescence in osteoarthritis. What is the most appropriate biomarker to evaluate the presence of senescent cells in her cartilage tissue?

A 65-year-old man with a history of heavy smoking presents with a persistent cough and hemoptysis (coughing up blood). Chest X-ray reveals a mass in the lung. Biopsy confirms lung adenocarcinoma. Tumor analysis reveals a somatic KRAS mutation. You propose a targeted therapy against the KRAS protein. However, the cancer progresses despite treatment. Further analysis reveals the cancer cells also have a loss-of-function mutation in the BAK gene. How can this mutation contribute to the resistance to KRAS-targeted therapy?

Scientists are investigating the potential of manipulating ferroptosis, a non-lysosomal iron-dependent form of cell death, for cancer therapy. They identify a drug that induces ferroptosis in cancer cells but has minimal effect on healthy cells. What is the MOST important consideration when designing a clinical trial for this drug?

A new diagnostic test is being developed to detect early signs of apoptosis in a specific type of cancer. The test measures the activation of a specific caspase early in the apoptotic pathway. However, researchers identify a subpopulation of cancer cells with mutations that bypass this caspase and activate the apoptotic pathway through a caspase-independent mechanism. How would this finding MOST likely impact the reliability of the new diagnostic test?

Next-generation sequencing reveals a complex mutational landscape in a patient's pancreatic cancer. While KRAS and TP53 mutations are identified, several other genes with less well-characterized mutations are also present. Which of the following statements is MOST consistent with the current understanding of pancreatic cancer development?

A 45-year-old male with a history of diabetes presents with a wound infection. Histological examination of the inflamed tissue reveals neutrophils adhered to the endothelium. Which molecule is primarily responsible for the initial rolling of leukocytes on the endothelial surface?

A 50-year-old male with rheumatoid arthritis is undergoing treatment with nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs primarily inhibit the cyclooxygenase pathway. Which of the following arachidonic acid metabolites is directly affected by NSAIDs?

A 40-year-old woman with a family history of breast cancer in her mother and maternal aunt is concerned about her risk. Genetic testing reveals a BRCA1 mutation. Which of the following best describes the interaction between her genetic predisposition and environmental factors?

A clinical trial is investigating a new chemotherapy drug for colon cancer. The trial includes patients with different genetic backgrounds. Which factor is most important to consider when analyzing the trial's outcomes?

A 72-year-old woman presents with a new diagnosis of ovarian cancer. Her history includes prolonged use of hormone replacement therapy (HRT). How does HRT contribute to the development of ovarian cancer?

A researcher is studying the pathogenesis of retinoblastoma using a knockout mouse model. Which genetic principle is illustrated by the requirement of two mutated alleles for tumor development in this model?

A study focused on the role of calcium in cell injury. Elevated intracellular calcium primarily contributed to cell death by activating which of the following enzymes?

A 45-year-old woman with a history of chronic myeloid leukemia (CML) is being treated with imatinib, a tyrosine kinase inhibitor. This drug specifically targets the BCR-ABL fusion protein. How does this treatment relate to the concept of oncogene addiction?

A 55-year-old male with chronic hepatitis B infection develops hepatocellular carcinoma. Which mechanism best explains the relationship between his chronic infection and cancer development?

A clinical trial is evaluating a new inhibitor targeting the RAS/RAF/MEK/ERK signaling pathway in metastatic melanoma patients with a BRAF V600E mutation. What is the primary molecular consequence of inhibiting this pathway?

Researchers are developing a novel therapeutic strategy targeting a specific oncogene in a particular type of lung cancer. In pre-clinical studies, they utilized a mouse model engineered to express the mutant oncogene specifically in lung epithelial cells. The mice developed lung tumors. To validate the therapeutic target, they performed a reverse genetics experiment using CRISPR-Cas9 to knockout the oncogene in a separate group of mice with the same engineered mutation. These knockout mice did not develop lung tumors. Based on these experiments, what can you conclude about the role of the targeted oncogene in lung cancer development?

A clinical trial investigates a new targeted therapy for melanoma, specifically targeting the BRAF V600E mutation. Why is it crucial to screen patients for this mutation before enrollment?

A laboratory experiment is conducted to study the effect of a novel oncogene on cell cycle regulation. Cells with an overexpressed oncogene are compared to wild-type cells. What would you expect to find in the oncogene-overexpressing cells?

A researcher is studying apoptosis in breast cancer cell lines MDA-MB-231 and uses a drug that downregulates BCl-2 and upregulates Bax and Bid. The cancer cells undergo apoptosis as a result. What is the most likely mechanism by which this drug induces apoptosis?

A patient with a mutation in the BAX gene presents with a highly aggressive form of lymphoma. As a molecular oncologist, you suspected that the mutation has affected the intrinsic pathway of apoptosis. What are the BCL-2 homology domains and function of BAX?

A patient with a mutation in the BCL2 gene presents with follicular lymphoma. As a molecular pathologist, you suspected that this mutation confers a survival advantage to the lymphoma cells. What is the primary role of the BCL2 gene in the intrinsic pathway of apoptosis?

In a research study, a knockout mouse model lacking the PUMA gene exhibited resistance to radiation-induced apoptosis. What role does the PUMA gene play in the intrinsic pathway of apoptosis?

A cancer patient is found to have a mutation in the BAD gene, resulting in its inactivation. What is the effect of BAD on the intrinsic pathway of apoptosis under normal conditions?

A novel anticancer drug is designed to downregulate the expression of MCL1 in tumor cells. What is the expected effect of this drug on the intrinsic pathway of apoptosis?

A 45-year-old woman with a history of breast cancer undergoes genetic testing, revealing a BRCA1 mutation. How does this mutation contribute to the molecular pathogenesis of cancer?

A laboratory experiment investigates the role of the BCL-2 protein in cancer cells. Overexpression of BCL-2 is observed to enhance tumor growth. Which hallmark of cancer does this overexpression directly relate to?

A 45-year-old patient presents with autoimmune lymphoproliferative syndrome (ALPS), characterized by defective apoptosis of lymphocytes. Genetic testing revealed a mutation in the FAS gene. Which of the following best describes the function of the FAS gene in the extrinsic pathway of apoptosis?

A 38-year-old patient is diagnosed with a type of cancer that shows resistance to apoptosis due to a mutation in the gene encoding TNFR1. How does TNFR1 contribute to the extrinsic pathway of apoptosis?

In an experimental setup, researchers use an siRNA to knock down the expression of the CASP8 gene in cancer cells. Which key process in the extrinsic pathway of apoptosis would be disrupted by this intervention?

In a phase II clinical trial, a new drug is tested for its ability to inhibit a specific form of programmed cell death in patients with metastatic melanoma. The trial reveals that the drug effectively prevents caspase-1 activation and IL-1β release in the tumor microenvironment. What type of cell death is most likely being inhibited?

A patient with a rare genetic disorder exhibits increased sensitivity to oxidative stress and early onset neurodegeneration. Genetic analysis reveals a mutation in the gene encoding glutathione peroxidase 4 (GPX4). This mutation most likely affects which type of cell death?

A new experimental treatment for cancer targets the MLKL protein in cancer cells. Preliminary studies show that inhibition of MLKL reduces tumor growth in mouse models. Which type of cell death is this treatment most likely targeting?

A researcher investigates a new drug targeting the EGFR pathway in non-small cell lung cancer (NSCLC). The drug specifically inhibits an EGFR mutation. What is the expected effect on cancer cell behavior?