Hallmarks and Signaling of Cancer Cells

Normal cells generate _____ molecules of ATP by breaking down one glucose molecule; by stark contrast, cancer cells only make _____ of ATP by breaking down one molecule of glucose. Please select the single best answer a.32 ... 2 b.2 ... 32 c.32 ... 32 d.2 ... 2

a.32 ... 2 Normal cells make 32 ATP molecules by breaking down one glucose molecule using the three-stage process of glycolysis, citric acid cycle, and oxidative phosphorylation. Cancer cells rely on glycolysis to generate two glucose molecules. To compensate this inefficiency of ATP production, cancer cells speed up ATP production as well as increasing glucose transporter levels. The other answers are not consistent with the description for ATP production by normal versus cancer cells.

Opdivo and Keytruda are two FDA-approved drugs that enable activation of _______ by blocking PD-1. Please select the single best answer a.Cytotoxic T cells b.Helper T cells c.B cells d.Plasma cells

a.Cytotoxic T cells Cytotoxic T cells, when activated, are capable of targeting and eliminating cancer cells. Cancer cells, however, utilize PD-1 to block cytotoxic T cell activation. Opdivo and Keytruda block PD-1 to liberate cytotoxic T cells. Under normal conditions, helper T cells are essential in activating cytotoxic T cells. B cells differentiate to become plasma cells to produce antibodies to fight infection.

Afatinib, Erlotinib, and Gifitinib are small molecule inhibitors that target non-small cell lung cancer positive for the _______ mutation. Please select the single best answer a.EGFR b.Ras c.Raf d.ERK

a.EGFR The three inhibitors all target the mutation in EGFR specifically. There are currently no inhibitors which target Ras or ERK that have been approved by FDA. Inhibitors which target Raf that are approved by FDA are used for melanoma treatment.

Cancer cells increase intracellular glucose levels by generating more: Please select the single best answer a.Glucose transporter proteins b.EGF receptors c.TGFβ receptors d.Nuclear receptors

a.Glucose transporter proteins The increased levels of glucose transporter proteins on cell surface help transport more glucose molecules intracellularly and each glucose molecules generates 32 molecules of ATP, the "fuel" for most of the cell's biochemical reactions. EGF receptors are transmembrane proteins located on cell surface and are activated by EGF binding. TGFβ receptors are transmembrane proteins located on cell surface and are activated by TGFβ binding. Nuclear receptors are transmembrane proteins located on the surface of the nucleus and mediate transport of molecules from the cytoplasm to the nucleus.

To initiate the Gap 1 (G1) phase of the cell cycle, _______ are required. Please select the single best answer a.Growth factors b.Cyclin D c.CDK4 d.Cyclin D and CDK4

a.Growth factors Growth factors are the initiators of the cell cycle. Cyclin D is part of cyclin D-CDK4 complex required for transition from G1 to S. CDK4 is part of the cyclin D-CDK4 complex required for G- to S transition. Cyclin D-CDK4 complex is required for transition from G1 to S.

Tumor development follows a progressive process described as: Please select the single best answer a.Normal --> Hyperplasia --> Dysplasia --> Carcinoma in situ --> Malignancy b.Normal --> Dysplasia --> Hyperplasia --> Carcinoma in situ --> Malignancy c.Normal --> Dysplasia --> Hyperplasia --> Malignancy --> Carcinoma in situ d.Normal --> Hyperplasia --> Dysplasia --> Malignancy --> Carcinoma in situ

a.Normal --> Hyperplasia --> Dysplasia --> Carcinoma in situ --> Malignancy The correct order is: Normal --> Hyperplasia --> Dysplasia --> Carcinoma in situ --> Malignancy The development from healthy normal cells to cancer follows the process of overgrowth (hyperplasia), to abnormal growth (dysplasia), to tumor within a confined area (carcinoma in situ), to cancer undergoing uncontrolled growth and invasion (malignancy).

______ is a complex molecule in that it is anti-proliferative in healthy cells; by contrast, in cancer cells especially late-stage cancer, it promotes cellular proliferation. Please select the single best answer a.TGFβ b.EGF c.Growth factor d.Oncogene

a.TGFβ TGFβ inhibits cell growth under normal, healthy conditions. EGF is the molecule that binds to EGFR to initiate the EGF/Ras signaling for important cellular processes including cell growth and differentiation. Growth factors are a family of molecules that promote cellular processes including cell growth and differentiation. Oncogenes are genes that when mutated, transform healthy cells to cancerous cells; hence, oncogenes promote uncontrolled growth.

Cancer cells enable themselves with unlimited growth potential by activating a protein called _______ to extend the life span of telomeres. Please select the single best answer a.Telomerase b.Telomere c.p21 d.p27

a.Telomerase Cancer cells produce telomerase to protect telomeres which in turn protect chromosomal ends. Hence, production of telomerase by cancer cells expands the life span of chromosomes to enable unlimited cell growth potential. Telomeres are the chromosomal ends protected by telomerases produced by cancer cells. p21 and p27 are cell cycle inhibitors.

At the end of a successful Synthesis (S) phase, the cell's chromosomes are ______. Please select the single best answer a.Increased b.Doubled c.Reduced d.Remain the same

b. Doubled It is true that upon completion of the S phase, the number of chromosomes is increased, but to answer "increased" is imprecise. To be exact, the cell's chromosomes are doubled. Human cells are DIPLOID: There are two sets of chromosomes, one inherited from the mother, the other from the father. In normal, healthy cells, at the end of the S phase, chromosomes are doubled but not decreased. If the number of chromosomes remain the same in number, it indicates the absence of a successful S phase.

At the end of the M phase of the cell cycle, one mother becomes _____ daughter cells with identical genetic information. Please select the single best answer a.1 b.2 c.4 d.8

b.2 2 daughter cells indicate that upon completion of one round of the cell cycle, one mother becomes 2 daughter cells with exact copies of the genetic materials. 1 daughter cell indicates absence of cell cycle progression. 4 daughter cells indicate 1 mother cell has undergone two rounds of cell cycles. 8 daughter cells indicate 1 mother cell has undergone three rounds of cell cycles.

Each molecule of glucose can be converted to generate ______ molecules of ATP as cellular fuel. Please select the single best answer a.16 b.32 c.64 d.128

b.32 The total number of ATP molecules generated by a single glucose molecule is 32 from the consecutive processes of glycolysis, citric acid cycle, and oxidative phosphorylation.

Please identify a frequently mutated oncogene found in non-small cell lung cancer (NSCLC) and additional cancer types: Please select the single best answer a.EGF b.EGFR c.p53 d.Rb

b.EGFR EGFR (epidermal growth factor receptor) is frequently found to be mutated in NSCLC as well as breast cancer, colorectal cancer, and glioblastoma. EGF (epidermal growth factor) is a growth factor involved in cell cycle initiation. p53 is a tumor suppressor gene. Rb is also a tumor suppressor gene.

Cancer cells migrate to adjacent healthy tissues and distal organs via _____. Please select the single best answer a.Phosphorylation b.Metastasis c.Nuclear translocation d.De-phosphorylation

b.Metastasis Cancer cells metastasize to adjacent healthy tissues and distal organs by complex processes including forming new vasculature, destabilizing cell attachment, and enabling cell motility. Phosphorylation refers to the transfer of a phosphate group. Nuclear translocation refers to the movement of a molecule from the cytosol to the cell nucleus. De-phosphorylation refers the removal of a phosphate group.

The cell division process usually slows down after approximately _____ rounds of divisions. Please select the single best answer a.10 b.30 c.50 d.100

c.50 After about 50 rounds, cell division slows down. Cells under such condition are considered as senescent, i.e., they are inactive but are still alive.

Orphan drugs refer to: Please select the single best answer a.Drugs that cannot be obtained on the U.S. market b.Drugs that are not approved by the FDA c.Drugs that treat rare disorders d.Drugs that treat common disorders

c.Drugs that treat rare disorders Orphan drugs refer to drugs that treat rare disorders with low prevalence. The definition of orphan drugs is not associated with their availability on the U.S. market. Both common drugs and orphan drugs must be approved by the FDA. Orphan drugs are the opposite of common drugs used to treat common disorders with high prevalence.

_______ are capable of engulfing and ingesting unwanted cells such as infected cells or cancer cells. Please select the single best answer a.Basophil b.Eosinophil c.Macrophage d.Killer T cells

c.Macrophage Macrophages phagocytize pathogens and unwanted cells including cancer cells. This phagocytic activity can occur during the early stages of cancer. As cancer progresses, macrophages can lose their phagocytic capacity and turn into cancer cell mediators. Basophils are immune cells of the innate immunity and are involved in type I hypersensitivity in that activated basophils interact with immunoglobulin E (IgE) and release pro-inflammatory mediators such as histamine, leukotrienes, and prostaglandins that cause allergic rhinoconjunctivitis and anaphylaxis. Similar to basophils, eosinophils are also immune cells of the innate immunity which interact with IgE, leading to the release of proinflammatory mediators that cause allergic reactions. Killer T cells (also called cytotoxic T cells) are immune cells of the adaptive immunity. Killer T cells are not phagocytes.

Immune cells capable of phagocytosis include: Please select the single best answer a.B cells b.Plasma cells c.Macrophages d.Basophils

c.Macrophages Macrophages are the chief phagocytes capable of engulfing and ingesting pathogens for destruction. B cells differentiate to become plasma cells. Plasma cells secret antibodies, also immunoglobulins. Basophils are immune cells of the innate immunity and are involved in type I hypersensitivity in that activated basophils interact with immunoglobulin E (IgE) and release pro-inflammatory mediators such as histamine, leukotrienes, and prostaglandins that cause allergic rhinoconjunctivitis and anaphylaxis.

The cellular checkpoint that blocks the transition from G1 to S is called ______. Please select the single best answer a.Epidermal growth factor (EGF) b.Fibroblast growth factor (FGF) c.Retinoblastoma protein (Rb) d.Cyclin D

c.Retinoblastoma protein (Rb) Retinoblastoma protein is the cellular "brake" to block the G1 to S transition. As the gene product of a tumor suppressor gene, Rb blocks cell cycle progression when it is not ready. Epidermal growth factor, is a soluble molecule that binds to a cell-surface receptor called epidermal growth factor receptor (EGFR). This binding and interaction initiates the EGF/EGFR signaling pathway which regulates several cellular processes including cell growth, differentiation, migration, and apoptosis. Similar to EGF, fibroblast growth factor (FGF) is also a soluble molecule that binds and interacts with FGFR. The FGF/FGFR signaling cascade regulates important cellular processes including cell growth and differentiation in addition to wound healing. Cyclin D is part of the cyclin D--CDK4 complex that phosphorylates Rb for de-activation, hence, ensuring cell cycle progression.

Tumor microenvironment constitutes of: Please select the single best answer a.The tumor proper b.Macrophages c.Fibroblasts d.All of the above

d.All of the above A tumor is surrounded by multiple cell types within the tumor microenvironment including fibroblasts, endothelial cells, and immune cells such as tissue macrophages and dendritic cells. The tumor proper is at the center of tumor microenvironment. Macrophages are infiltrating immune cells found in the tumor microenvironment. Fibroblasts are also found in the tumor microenvironment.

Features that characterize apoptosis include ___________. Please select the single best answer a.Shrinkage of overall cell size b.Cell membrane blebbing c.Chromosome condensation followed by cell nucleus collapse d.All of the above

d.All of the above Apoptosis, defined as programmed cell death, is characterized by multiple features including: Reduction of cell size Deformities of chromosomes and cell nucleus Abnormalities associated with cell membrane such as blebbing

Cancer cells grow uncontrollably due to: Please select the single best answer a.Mutation and inactivation of tumor suppressor genes b.Mutation and over activation of oncogenes c.Evading immune surveillance d.All of the above

d.All of the above Cancer cells enable themselves to grow uncontrollably by a combination of "strategies" including inactivation of TSGs, over-expressing oncogenes, and evading immune checkpoints, among other cancer hallmarks.

Oncogenes are defined as genes capable of transforming healthy cells to cancerous cells. Please identify oncogene(s) from the following choices: Please select the single best answer a.ERK b.Ras c.Raf d.All of the above

d.All of the above EGFR activation triggers the sequential activation of a cascade of components downstream. These include Ras, Raf, MEK, and ERK. These genes are essential in a variety of cellular processes including cell growth under both normal and cancerous conditions. The difference is that under normal conditions, signaling from these genes to direct cell growth is regulated; by contrast, under cancerous conditions, these genes are dysregulated by growth inhibitory signaling, leading to uncontrolled cell growth and cancer.

There are multiple cell types in the tumor microenvironment. These include: Please select the single best answer a.Tumor cells b.CAFs (cancer activated fibroblasts) c.TAMs (tumor-activated macrophages) d.All of the above

d.All of the above Tumor cells, CAFs, and TAMs are all found in the tumor microenvironment, contributing collectively to tumor growth and metastasis.

Cancer cells need a much greater supply of intracellular glucose compared to healthy normal cells because: Please select the single best answer a.Cancer cells have a phospholipid bilayer. b.Cancer cells have receptor proteins on cell surface. c.Cancer cells contain lysosomes. d.Cancer cells are constantly dividing and therefore need more glucose as fuel.

d.Cancer cells are constantly dividing and therefore need more glucose as fuel. Cancer cells need more glucose supply to enable constant cell division. Both healthy cells and cancer cells have a phospholipid bilayer. Both healthy and cancer cells are equipped with cell-surface receptor proteins. Both healthy and cancer cells have lysosomes as cytosolic organelles.

Identify the FDA-approved drug used in onco-immuno therapy: Please select the single best answer a.Gefitinib b.Erlotinib c.Apatinib d.Keytruda

d.Keytruda Keytruda (Pembrolizumab) is one of the few onco-immuno drugs approved by FDA. Keytruda binds to and incapacitate PD-L1, to promote activation of cytotoxic T cells which then unleash the "1-2 punch" of perforin and granzyme-B to eliminate cancer cells via apoptosis. Gefitinib, Erlotinib, and Apatinib are anti-cancer EGFR-targeting drugs

_____ is observed to be anti-proliferative in addition to regulating immune response under healthy conditions. By contrast, in malignancy, _____ promotes cancer cell growth and metastasis. Please select the single best answer a.p21 b.p27 c.p53 d.TGFβ

d.TGFβ TGFβ functions as a tumor suppressor gene in healthy cells, but in cancer cells especially during late-stage of malignancy, TGFβ takes on a reversal role to promote cancer cell proliferation and metastasis. p21 is a cell cycle inhibitor. p27 is also a cell cycle inhibitor. p53 is a tumor suppressor gene, also deemed as "guardian of genome".

Cancer cells become immortalized by producing ______ to protect telomeres. Please select the single best answer a.DNAse b.RNAse c.Proteinase d.Telomerase

d.Telomerase Telomerase is an enzyme responsible for adding nucleotides to telomeres at chromosomal ends, therefore, protecting chromosomal ends. DNAse is an enzyme that degrades DNA molecules. RNAse is an enzyme that degrades RNA molecules. Proteinase is an enzyme that degrades proteins.