Week Five: Genes, Cell Division, Cancer and the Environment

Read pp. 103-107; 128-129 (Cancer); review Betty’s lecture-week 2 (Cancer).

Read pp. 505-510; 597-610 (Genetics and the Environment)

 

Announcements for February 6th, 2001

1.      Midterm on Thursday February 8th

2.      5th week warnings will go out this week (make sure you turn in all your work)

3.      Introduction/literature review due at 3pm

4.      Buy “Bad Blood”  (Spring quarter book) by the 7th week.

 

Objectives:

·        To get a general understanding of what cancer is.

·        To learn the biology behind cancer

·        To see what factors (including environmental factors) are correlated with cancer

·        To learn about the various treatments for cancer

 

Important concepts

1.      Genes control whether and when cells divide

2.      Cancer involves mutations in several genes

3.      The environment greatly affects our health

 

 

CANCER: CELL DIVISION AND GENES (pp. 103-107)

1.      Cancer is a group of diseases that all involve uncontrolled division of cell

·        most cells can undergo a limited number of cell divisions

·        cancer cells can divide ad infinitum (immortal)

Q: why is the number of cell divisions limited?

 

2.      Cell division is under the control of certain genes

·        cell cycle genes regulate when cells divide

·        growth factors can promote cell division

 

3.      A tumor is a cluster of cells                                          Fig. 1

·        benign  tumors are slow growing

·        malignant tumors grow rapidly and tend to invade other tissues

·        metastasis is the movement of malignant tumor cells

 

4.      Normal cells can be transformed into cancer cells                  Fig. 2

·        carcinogens are chemicals or radiation that can transform cells

·        oncogenes are genes that cause cancer

·        oncogenes can develop from “normal” genes (proto-oncogenes)

 

5.      Characteristics of transformed cells include

·        undergo rapid cell division

·        detach from neighboring cells and often move about

·        are marked for destruction by the immune system

 

6.      Cancer involves mutations in several genes                      Fig. 3  

Q: what are the implications of this?

 

7.      Causes of cancer

·        inherited genes

·        carcinogens can transform cells

·        viruses can transform cells                                                  Fig. 4

·        mistakes during mitosis can lead to an oncogene

Q: If you inherit cancerous gene, will you get cancer? Explain!

 

 

HEALTH AND THE ENVIRONMENT: CANCER AND BEYOND

1.      Air pollution

·        greenhouse effect

·        global warming

·        smog

 

2.      Ozone depletion and skin cancer

·        ABCD rule: asymmetry, border irregularity, color variation and 6mm greater diameter are things to look for                                            Figs. 4.14/4.15

·        basal-cell carcinoma and squamous-cell carcinoma are not that dangerous

·        melanomas are the most dangerous

 

3.      Water pollution

·        ocean  pollution

·        river pollution

·        water tables

 

 

TREATMENT OF CANCER

1.      Immune defenses of your body

·        T cells

·        tumor-suppressor genes code for proteins which suppress tumor growth

 

2.      Radiation therapy

·        chemotherapy

 

3.      Early diagnosis

·        MRI

·        CT scan

·        PET scan

·        Self-examination (skin cancer, testicular cancer, breast cancer)

·        Yearly physicals

·        Self awareness (skin cancer, testicular cancer, breast cancer)

 

4.      Alternative treatments