BIOL3304 Ch20

Characteristics of Cancerous Tumors: Understanding the properties that distinguish cancerous tumors from normal tissues.
Loss of Cell Cycle Control: Explanation of how disruptions in the cell cycle lead to cancer.
Genetic Nature of Most Cancers: Insights into how most cancers are genetic but not necessarily inherited.
Description of Cancer Cells: Explore the unique features and behaviors of cancer cells.
Stem Cells in Cancer: Examination of how cancers can originate from stem cells.
Driver vs. Passenger Mutations: Understanding the distinction between mutations that contribute to cancer progression and those that do not.
Mutations in Cancer-Driving Genes: Discussion of multiple genes that play roles in cancer development.
Chromosomal Changes in Cancer Cells: Overview of what happens to chromosomes in the context of cancer.
Oncogenes and Tumor Suppressor Genes: Explanation of how mutations in these genes influence cancer susceptibility.
Environmental Factors: Analysis of how certain environmental factors contribute to cancer risk.
Diagnosis and Treatment Advances: How cancer diagnosis and treatment have increasingly incorporated genetic and genomic principles.

Nature of Cancer: Cancer entails abnormal cellular division, leading to tumors or altered blood cell types (liquid tumors).
- 1 in 3 people develop some form of cancer in their lifetime.
Heterogeneity of Cancer: Each patient’s cancer is unique; different tumors within the same individual can also diverge in characteristics.
Cancer's Progression: Cancer develops over time due to accumulated genetic and genomic changes.
Cell Cycle Derangement: Faulty cell cycle regulation as a primary factor in cancer onset, influenced by inherited risks or environmental exposures.
Research Advancements: Extensive genome sequencing of cancer cells aids in understanding the genetic underpinnings of the disease.

Impact of Mutations and Epigenetic Influences: Mutations in DNA can disturb gene expression and lead to cancer; epigenetic changes like DNA methylation also play a role.
Genomic Scars: Refers to the accumulation of DNA mutations leading to cancer.
Cell Fate and Survival: Cancer-related mutations affect cellular differentiation, survival mechanisms, and genomic maintenance.

Tumor Classification:
- Benign Tumor: Non-invasive, does not spread.
- Malignant Tumor: Infiltrates nearby tissues and can metastasize through blood or lymphatic systems.
Carcinogens: Agents that cause cancer, primarily by damaging DNA.

Whole-Body Level: Explores the diagnosis through symptoms, tests, and biomarkers.
Cellular Level: Diagnosis involves recognizing disrupted cellular pathways and genetic alterations.
Genomic Level: Identifies specific mutations that contribute to cancer, highlighting the complexity of the genetic landscape.

Categories of Cancer Genes:
- Oncogenes: Activate cancer when overexpressed or expressed inappropriately; effects are often dominant.
- Tumor Suppressor Genes: Lead to cancer when inactivated or deleted; their effects are recessive.
- DNA Repair Genes: Mutations in these genes allow for the survival of other mutations.

Cell Division Regulation: Faulty checkpoints in the cell cycle can lead to uncontrolled mitosis.
- Regulation is affected by protein growth factors and signaling molecules.
Consequences of Mutational Disruptions: Mutations that impede DNA repair mechanisms can result in cancer.

Cancer Stem Cells: These cells retain the potential for self-renewal and can give rise to differentiated cancer cells, contributing to tumor diversity.
Dedifferentiation: Occurs when specialized cells revert to a less specialized state, potentially leading to cancer.

Tissue Dynamics: Cancer can emerge from an increase in stem cell populations, affecting the balance of differentiated and progenitor cells.
Uncontrolled Repair Mechanisms: Chronic injuries may activate stem cells continuously, leading to cancerous growths.

Driver Mutations: Provide a selective advantage for cancer cells; involve key cancer-related genes.
Passenger Mutations: Occur incidentally; do not influence cancer's growth or spread.

Cancer Development Stages:
1. Breakthrough: Initial mutations lead to cancer initiation.
2. Expansion: Cancer cells proliferate unabated.
3. Invasion: Cells spread to local and distant sites.

Tumor Evolution: Genetic changes in tumors can lead to branching lineages, creating diverse tumor populations.

Mechanisms of Oncogene Activation: Includes point mutations, translocations, and environmental factors influencing proto-oncogenes.
Tumor Suppressor Gene Functions: Prevent cancer by regulating cell division; mutations can lead to cancer initiation.

Contribution to Cancer Risks: External factors can increase susceptibility to genetic mutations leading to cancer.

Genetic Testing: Utilization of testing for mutations (e.g., BRCA1/BRCA2) aids in cancer diagnosis and treatment decisions.
Liquid Biopsies: Non-invasive tests for tumor DNA in blood to monitor cancer progression and treatment effectiveness.

Evolution from non-selective treatments (surgery, radiation, chemotherapy) to targeted therapies focusing on specific mutations in cancer cells.