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Foundations of Medicine > Tumour Pathology > Flashcards

Tumour Pathology Flashcards

1
Q

What is a tumour?

A

An abnormal growing mass of tissue

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2
Q

Describe the growth of a tumour

A

Uncoordinated with that of surrounding normal tissues

Growth continues after the removal of any stimulus which may have caused the tumour

An irreversible change

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3
Q

What is an alternative term for tumour?

A

A neoplasm

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4
Q

What are the two types of tumours?

A

Benign - noncancerous
Malignant - cancerous

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5
Q

What does metastasise mean?

A

The ability of cancer to spread - cancers invade adjacent tissue and grow at other sites within the body

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6
Q

Define cancer

A

A malignant growth resulting in uncontrolled division of cells

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7
Q

What are the general features of cancer?

A

The major cause of death in the UK

Incidence of specific types of cancer increasing (males>female)

Genetic and environmental factors are important in the causation

Multistep process

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8
Q

What are the most common types of cancer in men?

A
  1. Prostate
  2. Lung
  3. Colon
  4. Kidney
  5. Melanoma (skin)
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9
Q

What are the most common types of cancer in women?

A
  1. Breast
  2. Lung
  3. Colon
  4. Uterus
  5. Melanoma (skin)
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10
Q

What are the most common types of cancer overall?

A
  1. Prostate
  2. Breast
  3. Lung
  4. Colon
  5. Melanoma
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11
Q

What are the five-year survival rates of the most common cancers?

A

Melanoma - 90%
Breast - 85%
Prostate - 85%
Uterus - 80%
Kidney - 60%
Colon - 60%
Lung - 10%

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12
Q

How are tumours classified?

A
  • Based on the tissue of origin
  • Benign vs malignant
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13
Q

What are examples of tissues from which tumours can arise?

A

Epithelium
Connective
Blood cells
Lymphoid tissues
Melanocytes
Neural tissue
Germ cells (ovary/testis)

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14
Q

What is the nomenclature of epithelial tissues?

A

Glandular

Benign: Adenoma
Malignant” Adeno-carcinoma

Squamous

Benign: Squamous papiloma
Malignant: Squamous carincoma

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15
Q

What are the names given to benign tumours that arise from connective tissues?

A

Bone - Osteoma
Fat - Lipoma
Fibrous tissue - Fibroma

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16
Q

What are the names given to malignant tumours for the connective tissues

A

Bone - Osteosarcoma
Fat - Liposarcoma
Fibrous tissue - Fibrosarcoma

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17
Q

What is the (malignant) tumour of the white blood cells called?

A

Leukaemia

No known benign tumours

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18
Q

Are there any tumours of the red blood cells?

A

No

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19
Q

What is the name given to (malignant) tumours of the lymphoid tissue?

A

Lymphoma

No known benign tumours

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20
Q

What names are given to tumours that arise from melanocytes?

A

Benign: Naevus
Malignant: Melanoma

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21
Q

What are tumours of the central nervous system called?

A

Astrocytoma

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22
Q

What are tumours of the peripheral nervous system called?

A

Schwannoma

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23
Q

What are germ cell tumours collectively known as?

A

Teratomas

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24
Q

Key points of the germ cell tumours

A

A tumour composed of different tissues
Develop in either the ovary or testis

Ovarian teratomas are usually benign
Testicular teratomas are usually malignant

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25
Q

What are features of benign tumours?

A

Non-invasive growth pattern
Usually encapsulated (contained)
No evidence of invasion
No metastases (does not spread)
Cells are similar to normal, healthy cells
Well-differentiated (look similar to nearby tissue)
Function similar to normal tissue
Rarely cause death

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26
Q

Features of Malignant Tumours

A

Invasive growth pattern
No capsule or the capsule is breached by tumour cells
Abnormal cells
Poorly differentiated
Loss of normal function
Frequently cause death

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27
Q

What are tumour suppressor genes?

A

A tumour suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication.

They inhibit cell proliferation and tumor development.

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28
Q

What is an oncogene?

A

A gene which in certain circumstances can transform a cell into a tumour cell.

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29
Q

What are the properties of cancer cells?

A

Loss of tumour suppressor genes
Gain of function of oncogenes
Altered cellular function
Abnormal morphology
Cells capable of independent growth
Presence of tumour biomarkers

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30
Q

What are examples of tumour suppressor genes?

A

Adenomatous polyposis (APC) - involved in colon cancer

Retinoblastoma (Rb) - involved in tumours of the retina of the eye

BRCA1 - involved in breast cancer

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31
Q

What are examples of oncogenes?

A

B-raf
Cyclin D1
ErbB2
c-Myc
K-ras
N-ras

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32
Q

What is B-raf associated with?

A

A range of tumours including melanoma

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33
Q

What is Cyclin D1 associated with?

A

Lymphoma

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34
Q

What is ErbB2 associated with?

A

Several types of tumours

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35
Q

What is c-Myc associated with?

A

Lymphoma

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36
Q

What are K-ras and N-ras associated with?

A

Several types of tumours but most notably colorectal cancer

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37
Q

What is a tumour biomarker?

A

Tumour-related proteins

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38
Q

What are the different categories of tumour biomarkers?

A

Onco-fetal proteins
Oncogenes
Growth factors and receptors
Immune checkpoint inhibitors

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39
Q

Describe the cellular function of cancer cells

A

Loss of cell-to-cell adhesion
Altered cell-to-matrix adhesion
Production of tumour related proteins aka biomarkers

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40
Q

What is the clinical usage of tumour biomarkers?

A

Screening

Diagnosis

Prognostic - identifying patients with a specific outcome

Predictive - identifying patients who will respond to a particular therapy

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41
Q

What is the biomarker for Teratoma of testis and hepatocellular carcinoma?

A

Alpha-fetoprotein

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42
Q

Where does hepatocellular carcinoma arise from?

A

Liver cancer arises from cells of the liver

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43
Q

What is the biomarker for colorectal cancer?

A

Carcino-embryonic antigen

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44
Q

What is the biomarker for Breast cancer?

A

Oestrogen receptor

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45
Q

What is the biomarker for Prostate cancer?

A

Prostate specific antigen

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46
Q

What are the predictive tumour biomarkers for colorectal cancer?

A

K-ras, an oncogene

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47
Q

What are the predictive tumour biomarkers for lung cancer?

A

EGFR - epidermal growth factor receptor
PD-L1 - an immune checkpoint

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48
Q

What are the predictive tumour biomarkers for breast cancer and gastric cancer?

A

Her2

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49
Q

What are the predictive tumour biomarkers for melanoma?

A

Braf

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50
Q

What is the variation in size and shape of cancer cells referred to as?

A

Pleomorphism

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51
Q

Is mitosis present in cancer cells?

A

Yes however it is abnormal

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52
Q

What is tumor growth?

A

A balance between cell growth and cell death

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53
Q

What two processes are vital in tumour growth?

A

Angiogenesis
Apoptosis

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54
Q

What is angiogenesis?

A

Angiogenesis is the formation of new blood vessels by tumors which is required to sustain tumor growth.

The more blood vessels in a tumour, the poorer the prognosis

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55
Q

What does angiogenesis provide a route to?

A

Release of tumour cells

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56
Q

What is apoptosis?

A

Mechanism of programmed and controlled single cell death.

It is an active cell process that regulates tumour growth and is involved in response to chemotherapy and radiotherapy.

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57
Q

How can the spread of cancer be divided up?

A

Invasion
Metastasis

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58
Q

What is a major clinical problem of cancer?

A

Formation of metastatic (secondary) tumours

Prognosis depends on extent of cancer spread

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59
Q

What are the characterizations of invasion and metastasis?

A
  • Multi-step process
  • Increased matrix degradation by proteolytic enzymes
  • Altered cell-to-cell and cell-to-matrix adhesion
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60
Q

What are the modes of cancer spread?

A

Local - spread to adjacent anatomical structures. Invasion.
Lymphatic
Blood
Trans-coelomic - a special type of local spread. Spread between body cavities ie the pleural cavity

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61
Q

Steps in tumour invasion

A

Malignant tumout
Invasion into connective tissue
Invasion into lymph/blood vessles

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62
Q

Steps of tumor metastasis via lymphatics

A

Adherence of tumor cells to lymph vessels
Invasion from lymphatics
Invasion into the lymph node
Formation of metastasis in lymph node
Clinical evidence of metastasis

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63
Q

Steps of tumor metastasis via blood

A

Adherence of tumour cells to blood vessels
Invasion from blood vessels
Invasion into tissue
Formation of metastasis
Clinical evidence of metastasis

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64
Q

What type of tumors show trans-coelomic spread?

A

Tumours of lung, stomach, colon and ovary

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65
Q

What are the common sites of metastasis?

A

Liver, lung, brain, bone (axial skeleton), adrenal gland, omentum/peritoneum

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66
Q

What are the uncommon sites of metastasis?

A

Spleen, kidney, skeletal muscles, heart

Relates to blood flow and the environmental factors of each organ

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67
Q

Where do breast, prostate, and colorectal cancer often metastasize to?

A

Breast - bone
Prostate - bone
Colorectal - liver
Ovary - omentum/peritoneum

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68
Q

Local effects of benign tumors

A

Pressure
Obstruction - especially if the tumor is in a hollow structure such as the intestine

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69
Q

Local effects of malignant tumours

A

Pressure
obstruction
Tissue destruction - ulceration/infection
Bleeding, if tumour erodes into blood vessels- anemia, haemorrhage
Pain - pressure on nerves, perineural infiltration (area surrounding the nerves), bone pain from pathological fractures
Effects of treatment

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70
Q

What is perineural infiltration?

A

The process of neoplastic invasion of nerves and is an under-recognized route of metastatic spread.

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71
Q

What are systemic effects of a malignant tumour?

A

Unplanned weight loss may amount to cancer cachexia if weight loss is significant and sustained

Secretion of hormones - can be either normal or abnormal. Can also promote weightloss.

Paraneoplastic syndromes - a group of uncommon disorders that develop in some people who have cancer

Effects of treatment

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72
Q

What is normal hormone production by tumors?

A

Hormones are produced by tumors of the endocrine organ but there is abnormal control of hormone production/secretion

Secreted either at an inappropriate time or in response to an inappropriate stimulus or in an appropriate amount.

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73
Q

What is abnormal hormone production by tumors?

A

Produced by tumour from an organ that does not normally produce hormones

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74
Q

What is an abnormal hormone secretion caused by lung cancer tumours?

A

ACTH
ADH

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75
Q

What are paraneoplastic syndromes?

A

Cannot be explained by local or metastatic effects of tumors eg neuropathy, myopathy

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76
Q

Why is it important to detect cancer at an early stage?

A

Reduce/prevent morbidity and moratlity

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77
Q

Morbidity vs morality

A

Morbidity refers to an illness or disease.
Mortality refers to death.

78
Q

How can cancer be detected at a pre-invasive stage?

A

Detection of dysplasia/intraepithelial neoplasia

79
Q

What is dysplasia?

A

Dysplasia is a broad term that refers to the abnormal development of cells within tissues or organs.

80
Q

Features of dysplasia

A

Pre-malignant change
Earliest change in the process of malignancy that can be visualized
Identified in the epitheliuim
No invasion but can progress to cancer

81
Q

What are the features of dysplasia?

A

Disorganisation of cells - increased nuclear size, mitotic activity and abnormal mitoses
Grading of dysplasia - low and high
No invasion

82
Q

What does early detection of cancer need?

A

Effective test that is sensitive/specific and accetable

83
Q

What is cervical cancer screening used to reduce?

A

Detects oncogenic HPV of the squamous carcinoma of the cervix to rncidence of the squamous carcinoma of the cervix

Established NHS program

84
Q

What is the cell cycle defined as?

A

The interval between mitotic divisions

85
Q

What are the external factors that affect cell cycle control?

A

Hormones, growth factors, cytokines, stroma

86
Q

When is the cell cycle dependant on external stimuli and when is it autonomous?

A

Prior to restriction point - external stimuli

After restriction point - autonomous

87
Q

What is the genome chromosome pair?

A

The human genome is stored on 23 chromosome pairs. 22 of these are autosomal chromosome pairs, while the remaining pair is sex-determining.

88
Q

How many chromosomes are in a cell?

A

23 pairs of chromosomes
46 total chromosomes

89
Q

What does each turn of the cell cycle do?

A

Divides the chromosomes in a cell nucleus

90
Q

What does mitosis start and end as?

A

Diploid cell produced 2 genetically identical diploid cells

91
Q

What does meiosis start and end as?

A

Diploid cell produces 4 haploid daughter cells

92
Q

What are the three periods the cell cycle can be divided into?

A

Interphase
Mitosis
Cytokinesis

93
Q

What happens in interphase?

A

Cell grows and accumulates nutrients needed for mitosis;

Cell is synthesizing RNA, producing protein and growing in size.

The molecular events that regulate the cycle are ordered .

94
Q

What stages make up interphase?

A

G1
S
G2

95
Q

What happens during mitosis?

A

Cell splits itself into two genetically identical daughter cells (diploid cells)

96
Q

What happens during cytokinesis?

A

New cell is completely divided

97
Q

What happens in G1?

A

Cell increases in size

Cellular contents are duplicated

98
Q

What happens in S phase?

A

DNA replication

Each of the 46 chromosomes (23 pairs) is replicated by the cell

99
Q

What happens in G2?

A

Cell grows more

Organelles and proteins develop in preparation for cell division

100
Q

What happens in M phase?

A

Mitosis followed by cytokinesis (cell separation)

Formation of two identical daughter cells

101
Q

What happens in G0?

A

While some cells are constantly dividing, some cell types are quiescent.

These cells exit G1 and enter a resting state called G0.

In G0, a cell is performing its function without actively preparing to divide. G0 is a permanent state for some cells, while others may re-start division if they get the right signals.

102
Q

What is the progression of cells through the cell cycle is controlled by?

A

By various checkpoints at different stages.

103
Q

What do checkpoints in the cell cycle detect and what does it do?

A

If a cell contains damaged DNA and ensure those cells do not replicate and divide.

104
Q

Where can the restriction checkpoint (R) be found?

A

The restriction point (R) is located at G1 and is a key checkpoint.

The vast majority of cells that pass through the R point will end up completing the entire cell cycle.

105
Q

What happens if damaged DNA is detected during any checkpoint?

A

Activation of the checkpoint results in increased p53 protein production.

106
Q

What is p53 and what does it do?

A

A tumour suppressor gene

Stops progression of the cell cycle and starts repair mechanisms for the damaged DNA.

107
Q

What happens to damaged DNA if they can not be repaired by p53?

A

The cell undergoes apoptosis and can no longer replicate.

108
Q

What are the checkpoints in the DNA cycle?

A

G1
G2
Metaphase

109
Q

What does the G1 checkpoint detect?

A

Inadequate nutrient supply
External stimulus lacking
Abnormal cell size
DNA damaged

110
Q

What does the G1 checkpoint detect?

A

Abnormal cell size
DNA damage
Unreplicated DNA

111
Q

If the DNA is not replicated, where will the cell cycle cease?

A

S phase

112
Q

If DNA damage is detected, where will the cell cycle cease?

A

G1 or G2

113
Q

If there is chromosome misalignment, where will the cell cycle cease?

A

Metaphase

114
Q

What is the main purpose of the G1, G2 and M phase checkpoints?

A

G1 - Checks DNA integrity

G2 - Checks proper
chromosome duplication

M - Assesses attachment of each kinetochore to a spindle fiber

115
Q

What is an example of a tumour suppressor protein that works in the cell cycle?

A

Retinoblastoma protein (Rb).

Rb restricts the ability of a cell to progress from G1 to S phase in the cell cycle.

116
Q

What does CDK do?

A

CDK phosphorylates Rb to pRb, making it unable to restrict cell proliferation, thereby inhibiting its cell growth-suppressing properties.

This allows cells to divide normally in the cell cycle.

117
Q

What external facts can affect the cell cycle?

A

Cytokines
Growth factors
Horomes

118
Q

What is the role of cytokines?

A

Cytokines regulate cell proliferation by cell-cycle-regulatory proteins, in which cyclin-dependent kinase inhibitors (CDKI) inhibit cell proliferation.

119
Q

What are the catalytic sub-units called and what are they activated by?

A

Cyclin dependant kinases Activated by a regulatory sub-units called cyclins

120
Q

What is the name given to the active enzyme complex?

A

CDK/cyclin complex

121
Q

What is the effect of CDK/cyclin complexes?

A

Phosphorylate target proteins

122
Q

What is the result of the CDK/cyclin complexes phosphorylating the target proteins?

A

Results in activation or inactivation of that substrate

123
Q

What is the function of the substrates that are inactivated or activated by CDK/cyclin complexes?

A

Substrates regulate what happens in the next phase of the cell cycle

124
Q

How are CDK’s and cyclins regulated?

A

CDK’s are constitutively expressed in an inactive form

Cyclins accumulate and are destroyed as cycle progresses

CDK inhibitors

124
Q

How are CDK’s and cyclins regulated?

A

CDK’s are constitutively expressed in an inactive form

Cyclins accumulate and are destroyed as cycle progresses

CDK inhibitors

125
Q

What are the two methods of inhibition of the CDK inhibitors?

A

Bind to CDK and prevent the association of these CDK’s with their cyclin regulatory proteins. They bind to the CDK/cyclin complexes

126
Q

What are the environmental factors that can cause genetic damage?

A

Chemicals
Radiation
Oncogenic viruses

127
Q

What are the targets for radiation carcinogenesis?

A

Purine and pyrimidine bases

128
Q

Which forms of high energy radiation are carcinogenic?

A

Ultraviolet radiation
X rays
Gamma radiation

129
Q

Which genes mutate at G1-S to cause cancer?

A

Rb, CDK4, Cyclin D and p16

130
Q

What is the function of P53?

A

Maintains genomic integrity

131
Q

What is the effect of increased levels of P53?

A

Cell cycle arrest at G1
Facilitates DNA repair
Apoptosis

132
Q

What is the effect of a mutated P53 gene?

A

No G1 arrest or repair of DNA

Genetically damaged cells proliferate and form malignant neoplasms

133
Q

What are the cell cycle inhibitors?

A

CDK inhibitors (CDKIs) - inhibitor molecules binding to cyclin/CDK complexes

134
Q

What are the two families of genes that prevent cell cycle progression ?

A

INK41 gene family - p16
GIP/KIP gene family - p21, p27

135
Q

What is the function of the pRb phosphoprotein?

A

CDK/cyclin complexes phosphorylate this protein. Once phosphorylated it becomes inactive and loses affinity for the E2F transcription factor.This free E2f now activates vital target genesE2F is a potent stimulator of cell cycle entry

136
Q

What does cell cycle balance?

A

Propliferation and apoptosis

137
Q

What is carcinogenesis?

A

Failure of cell cycle control, balance between proliferation and apoptosis is distrupted

138
Q

What causes carcinogenesis?

A

Mutations in genes regulating cell division, apoptosis, and DNA repair cause a cell to lose control of proliferation

139
Q

What does uncontrolled proliferation of cells cause?

A

Tumours

140
Q

What are the two regulatory pathways disrupted in carcinogenesis?

A

1.The cyclin D-pRb-E2F pathway

  1. p53 pathway
141
Q

Where are all cancers dysregulated?

A

G1-S

142
Q

What are mutated cell cycle regulating genes?

A

Cyclin D
CDK4
p16
Rb

143
Q

How do tumour suppressor genes function?

A

Discourage cell growth or temporarily halt cell division to carry out DNA repair

144
Q

What is an anti-oncogene?

A

A tumour suppressor gene

Responsible for Apoptosis
DNA repair and the negative regulation of mitosis

145
Q

What do mutations in retinoblastoma gene cause?

A

Favour cell proliferation since it is an anti-oncogene (a tumour suppressor gene)

146
Q

What other mutations can cause the same effect of a mutated RB gene?

A

Mutational activation of Cyclin or CDK (naturally responsible for the phosphorylation of the pRB)

Mutational inactivation of CDKI’s

147
Q

What is the inherited form of oncogenesis?

A

One defective copy of the RB gene

Somatic point mutation of the other copy

148
Q

What is the sporadic form of oncogenesis?

A

Both hits occur in a single cell

149
Q

What does mutation of tumour suppressor genes cause?

A

Loss of function

150
Q

What is the two hit hypothesis of tumour suppressor genese?

A

Tumour suppressor alleles are usually recessive

Loss of both normal allelic copies gives rise to cancer

151
Q

Discuss inherited cancer

A

Account for 5-10% of all cancers

Genetic predisposition to develop cancer

Early onset of multiple tumours

152
Q

Discuss the inherited predisposition to familial retinoblastoma cancer

A

Carriers have 10000x risk of bilateral retinoblastoma

Increased risk of second cancers eg bone sarcomas

Autosomal dominant pattern

153
Q

Discuss the inherited predisposition to familial adenomatous polyposis of colon

A

Thousands of polyps

100% risk of colon cancer by age 50 years

Caused by a defect in the adenomatous polyposis coli (APC) gene.

Autosomal dominant pattern

154
Q

Discuss the inherited predisposition to Hereditary Non-polyposis Colorectal Cancer Syndrome

A

Germline mutations in DNA mismatch repair genes

hMSH2, hMLH1, MSH6

Autosomal dominant inheritance.

155
Q

What is the function and the inherited mutation of APC?

A

Function: Signal transduction
Inherited mutation: FAP colon cancer

156
Q

What is the function and the inherited mutation of p53?

A

Function: cell cycle/apoptosis after DNA damage

Inherited mutation:

Li-Fraumeni syndrome:
Multiple carcinomas and sarcomas

157
Q

What is the function and the inherited mutation of Rb?

A

Function: Cell cycle regulation
Inherited mutation: Retinoblastoma, osteosarcoma

158
Q

What is the function and the inherited mutation of p16(INK4a)?

A

Function: inhibits CDK’s
Inherited mutation: malignant melanoma

159
Q

What are proto-oncogenes?

A

Normal genes coding for normal growth regulating proteins:

Growth factors
Growth factor receptors
Signal transduction

160
Q

What are cancer causing genes?

A

Oncogenes that are derived from proto-oncogenes

161
Q

Which gene is responsible for DNA repair and causes breast and ovarian cancer?

A

BRAC 1/2

162
Q

What are oncogenes activated by?

A

Alteration of proto-oncogene structure

163
Q

What happens when there is dysregulation of proto-oncogene expression?

A

Gene amplification
Over expression

164
Q

What can cause dysregulation of proto-oncogene expression?

A

Gene amplification
Over expression

165
Q

What can cause alteration of proto-oncogene structure?

A

Point mutation

Chromosome rearrangements + translocations

166
Q

Give examples of oncoprotein products

A

Growth factors
Growth factor receptors
Proteins involved in signal transduction
Nuclear regulatory proteins
Cell cycle regulators

167
Q

What mutation of the PDGF growth factor causes Astrocytoma and osteosarcoma’s?

A

Over expression

Proto-oncogene: sis

168
Q

What mutation of the growth factor receptor EGF causes Breast ovarian lung and stomach cancer?

A

Amplification

Proto-oncogene: HER2/neu

169
Q

What mutation in GTP binding signal transducaers causes lung, colon, pancreas, leukaemia?

A

Point mutation

Proto-oncogene: ras

170
Q

What mutation in transcriptional activators (a nuclear regulatory protein) causes Burkitt lymphoma?

A

Translocation

Proto-oncogene: myc

171
Q

What type of mutation are cell cycle regulators Cyclin D and CDK4 susceptible to?

A

Amplification

Cyclin D also susceptible to translocation

172
Q

What type of cancer can a mutation in Cyclin D cause?

A

Translocation - mantle cell lymphoma

Amplification - breast, liver, oesophageal

173
Q

What type of cancer does a mutation in cyclin dependant kinase cause?

A

Melanoma, sarcoma

174
Q

What are the mechanisms of viral carcinogenesis?

A

Virus genome inserts near a host proto - oncogene

Viral promoter or other transcription regulator causes proto-oncogene over expression

Retroviruses insert oncogene into host DNA causing cell division.

175
Q

Chemical carcinogenesis involves adduct formation, what does this lead to?

A

Activation of oncogenes and suppression of anti-oncogenes

176
Q

What is a neoplasm?

A

A new and abnormal growth of tissue in the body.

177
Q

What is the function of the p16 protein?

A

It is an inhibitor of the CDK’s which are involved in the phosphorylation of the of the pRB - progression from G1 to S phase

178
Q

What happens when pRB is bound to E2F?

A

The complex acts as a growth suppressor - prevents progression through the cell cycle

When unbound - no inhibition exists - progression is possible

179
Q

Discuss multistep carcinogenesis?

A

All sporadic cancers harbour multiple genetic aberrations

Mutations accumulate with time

Activation of several oncogenes and loss of two or more anti-oncogenes occurs in most cancers

180
Q

What causes chemical carcionogenesis?

A

Purine and pyrimidine bases in DNA are critically damaged by oxidizing and alkylating agents

Chemical carcinogens react with DNA forming covalently bound products (DNA adducts)

Adduct formation can lead to activation of oncogenes and loss of anti-oncogenes

181
Q

What causes viruses can cause cancer?

A

HPB - genital, throat and anal cancers
Hep B - liver cncer
EBV - lymphoma

182
Q

What are the stages of mitosis?

A

Prophase
Metaphase
Anaphase
Telophase

183
Q

What can help you remember stages of mitosis?

A

Pee on the MAT

184
Q

What happens in interphase?

A

The cell spends most of its life in this phase. The DNA in chromosomes copies itself ready for mitosis.

185
Q

What happens in prophase?

A

The DNA in chromosomes and their copies condenses to become more visible. The membrane around the nucleus disappears.

186
Q

What happens in metaphase?

A

The nuclear membrane breaks down. Chromosomes and their copies line up in the middle of the cell.

187
Q

What happens in anaphase?

A

Chromosomes and their copies are pulled to different ends of the cell.

188
Q

What happens in telophase?

A

New membranes form around the chromosomes at each end of the cell.

189
Q

What happens in cytokineses?

A

The cell membrane pinches in and eventually divides into two daughter cells.

Foundations of Medicine (56 decks)

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