PART 2 : TME et ECM

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Questions and Answers

What enables cancer cells to be self-sufficient in growth signals?

Upregulation of anti-apoptotic mediators.

Activation of caspases.

Ability to synthesize their own growth factors. (correct)

Increased apoptosis.

What molecule is downregulated in cancer cells, reducing contact inhibition?

E-cadherin (correct)

Cyclin D

TGF-β

VEGF

How do cancer cells evade apoptosis?

Overexpression of Bcl-2 and downregulation of Bax and Bak. (correct)

Increased sensitivity to FasL/FasR signaling.

Activation of caspases.

Upregulation of BH3-only proteins.

Which mutation is commonly found in cancer cells to prevent apoptosis?

p53 mutation (A) Signup and view all the answers

What process enables cancer cells to have limitless replicative potential?

Overactivation of telomerase reverse transcriptase (TERT) (A) Signup and view all the answers

What is the role of VEGF in cancer?

Angiogenesis (A) Signup and view all the answers

Which feature distinguishes cancer cells as "immortal"?

Overactivation of telomerase (A) Signup and view all the answers

How do cancer cells promote tissue invasion?

Through secretion of matrix metalloproteinases (MMPs). (C) Signup and view all the answers

What happens when TGF-β signaling is lost in cancer cells?

Cells lose their sensitivity to anti-growth signals. (C) Signup and view all the answers

What pathway is altered in cancer to promote growth signal transduction?

MAPK pathway (B) Signup and view all the answers

What is the primary metabolic feature of cancer cells?

Warburg effect (B) Signup and view all the answers

What is the main metabolic difference between cancer cells and normal cells?

Cancer cells produce ATP primarily via glycolysis, even in aerobic conditions. (D) Signup and view all the answers

Which metabolic process is upregulated in cancer cells to support rapid growth?

Protein synthesis (B) Signup and view all the answers

Why is the Warburg effect advantageous to cancer cells?

It supports rapid energy generation despite lower efficiency. (C) Signup and view all the answers

What is the major byproduct of cancer cell metabolism under aerobic conditions?

Lactate (B) Signup and view all the answers

Which protein is upregulated in cancer cells to enhance glucose uptake?

GLUT1 (B) Signup and view all the answers

What drives the high anabolic activity of cancer cells?

Increased biosynthetic pathways (e.g., nucleotide synthesis) (C) Signup and view all the answers

Which of the following is NOT a hallmark of cancer cell metabolism?

Decreased ATP demand (C) Signup and view all the answers

What adaptation allows cancer cells to tolerate high ROS levels?

Enhanced antioxidant systems (C) Signup and view all the answers

Which transcription factor is activated in cancer cells under hypoxia?

HIF-1 (B) Signup and view all the answers

What is a major consequence of chronic inflammation in cancer?

Stimulated angiogenesis (C) Signup and view all the answers

Which cells secrete matrix metalloproteinases (MMPs) in the tumor microenvironment?

Cancer cells and inflammatory cells (A) Signup and view all the answers

Which factor is constitutively activated in hypoxic cancer environments?

HIF-1 (A) Signup and view all the answers

Which immune cells play a key role in promoting inflammation in tumors?

M1 macrophages (D) Signup and view all the answers

What role does ROS play in cancer progression?

Causes DNA damage and supports tumor growth (B) Signup and view all the answers

What type of immunity involves macrophages and neutrophils?

Innate immunity (A) Signup and view all the answers

Which immune cells are involved in antigen presentation to T cells?

Dendritic cells (A) Signup and view all the answers

What is the role of cytotoxic CD8+ T cells in cancer?

Directly kill tumor cells. (C) Signup and view all the answers

How does hypoxia in the tumor microenvironment affect T cells?

Promotes T cell exhaustion. (B) Signup and view all the answers

What is the role of M1 macrophages in cancer?

Pro-inflammatory, fighting tumor progression. (C) Signup and view all the answers

What phenotype do macrophages switch to in the immunosuppressive tumor microenvironment?

M2 (D) Signup and view all the answers

Which immune cells produce specific antibodies in the adaptive immune response?

B cells (D) Signup and view all the answers

Which molecule contributes to immune suppression in the tumor microenvironment?

TGF-β (B) Signup and view all the answers

What is the function of regulatory T cells (Tregs) in the tumor microenvironment?

Suppress the immune system. (B) Signup and view all the answers

What process is mediated by myeloid cells in the early tumor elimination phase?

Anti-tumoral response (B) Signup and view all the answers

What is the primary structural protein in the ECM?

Collagen (C) Signup and view all the answers

What is the role of matrix metalloproteinases (MMPs) in cancer?

Promote collagen degradation and tumor invasion. (C) Signup and view all the answers

What molecule provides adhesive support in the ECM?

Both b and c (C) Signup and view all the answers

How does the ECM contribute to tumor progression?

Provides physical support and regulates cellular functions. (D) Signup and view all the answers

What hallmark is associated with cancer-associated fibroblasts (CAFs)?

Secretion of TGF-β and FGF to remodel the ECM. (B) Signup and view all the answers

What modification in the ECM prevents immune cell infiltration?

Matrix deposition and stiffening by CAFs. (D) Signup and view all the answers

Which signaling molecule polarizes fibroblasts into cancer-associated fibroblasts?

TGF-β (C) Signup and view all the answers

What molecule increases ECM stiffness and promotes tumor growth?

Collagen (C) Signup and view all the answers

Which ECM component regulates cell communication?

Integrins (A) Signup and view all the answers

How does ECM remodeling aid metastasis?

Provides haptokinetic cues and creates a path for invasion. (A) Signup and view all the answers

What is the key feature of epithelial-to-mesenchymal transition (EMT) in cancer?

Loss of cell adhesion and increased motility. (B) Signup and view all the answers

What is the primary driver of EMT in cancer?

TGF-β signaling (D) Signup and view all the answers

What is the first step in metastasis after EMT?

Intravasion (B) Signup and view all the answers

What is the predominant mode of migration in solid tumors?

Mesenchymal migration (B) Signup and view all the answers

What role do MMPs play in the EMT-to-metastasis transition?

Degrade ECM components to allow tumor cell invasion. (A) Signup and view all the answers

Study Notes

Cancer Cell Characteristics

Cancer cells are self-sufficient in growth signals due to their ability to synthesize their own growth factors.
Contact inhibition is reduced in cancer cells due to downregulation of TGF-β (transforming growth factor-beta), a molecule.
Cancer cells evade apoptosis via overexpression of Bcl-2 and downregulation of Bax and Bak. This prevents programmed cell death.
A p53 mutation is common in cancer cells preventing apoptosis.

Cancer Cell Replication

Cancer cells have limitless replicative potential due to overactivation of telomerase reverse transcriptase (TERT).
VEGF (vascular endothelial growth factor) plays a crucial role in angiogenesis, the formation of new blood vessels, in cancer.

Cancer Cell Immortality

Overactivation of telomerase is a key feature distinguishing cancer cells as "immortal".
Cancer cells promote tissue invasion through secretions of matrix metalloproteinases (MMPs).

Cancer Cell Metabolism

The primary metabolic feature of cancer cells is the Warburg effect, where they prefer glycolysis, even in the presence of oxygen, to produce energy. This results in higher lactate production.
Cancer cells require glucose for survival.
The Warburg effect is advantageous to cancer cells because it supports rapid energy generation despite lower metabolic efficiency.
Lactate is a major byproduct of cancer cell metabolism under aerobic conditions.
GLUT1 (glucose transporter 1) enhances glucose uptake in cancer cells.

Inflammation and Cancer

Chronic inflammation leads to increased DNA damage as a significant consequence.
M1 macrophages play a critical role in promoting inflammation and fighting cancer progression, distinguishing themselves from other immune cells by promoting inflammatory pathways.
Hypoxia leads to constitutive activation of HIF-1 in cancer environments.

Immune Cells in Cancer

Macrophages and neutrophils are involved in innate immunity.
Dendritic cells are responsible for antigen presentation to T cells, activating adaptive immune responses crucial for tumor elimination.
Cytotoxic CD8+ T cells directly kill tumor cells.
Regulatory T cells (Tregs) suppress the immune system, promoting tumor growth by inhibiting anti-tumoral immune responses.

Extracellular Matrix (ECM)

Collagen is the primary structural protein in the ECM.
Matrix metalloproteinases (MMPs) are crucial in cancer due to their role in degrading the ECM, promoting collagen breakdown, and enabling tumor invasion.
ECM remodeling is beneficial for metastasis due to the establishment of an invasion pathway.
Fibronectin and laminin are ECM components that regulate cell communication, aiding cell attachment and signaling.
Cancer-associated fibroblasts (CAFs) secrete TGF-β and FGF to remodel the ECM.

EMT (Epithelial-Mesenchymal Transition)

EMT is a critical process during cancer that leads to increased cancer cell motility and invasion in solid tumors.
TGF-β signaling is a major driver of EMT in cancer.
EMT transition is the prerequisite to metastasis after extravasation.
The predominant mode of migration in solid tumors is mesenchymal migration.
MMPs play a critical and critical role in the EMT-to-metastasis transition during cancer.

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Description

Explore the unique characteristics and behaviors of cancer cells in this quiz. Learn about their ability to grow uncontrollably, evade cell death, and their distinct metabolic properties. This quiz covers essential topics that highlight the underlying mechanisms of cancer development and progression.