immunology 3 Flashcards
Tumor Markers
proteins released into the serum by tumors that can be used to screen populations for cancer and to monitor for recurrence after treatment
PSA, CEA, Alpha Fetoprotein
lack specific and sensitivity for early detection of cancer
PSA
prostate specific antigen and prostatic adenocarcinonma
CEA
carcinoembryonic antigen and carcinomas of the colon, pancreases, stomach, breast
BS PC
Alpha Fetoprotein
hepatocellular carcinoma, teratocarcinomas, embryonal cell carcinomas
-most likely used in the screening of patients for cancer
Tumor antigens
CTLs are the major immune defense mechanism against tumors
Tumor specific antigens
only on tumor cells (oncogenes and anti-oncogenes)
Tumor Associated antigens
on tumor an some normal cells
Benign tumor
its microscopic and gross characteristics are relatively innocent, implying that it will remain localized and is amenable to local surgical removal
neoplasia
new growth
oncology
study of tumor
malignant tumor
collectively referred to as cancer, the lesion can invade and destroy adjacent structures and spread to distant sites to cause death
Differentiation and Anaplasia
benign neoplasms are composed of well-differentiated cells that closely resemble their normal counterparts
-lack of differentiation, or anaplasia, is a hallmark of malignancy
Rate of Growth
- benign neoplasms are slow growing
- correlates inversely with level of differentiation of malignant tumors i.e. poorly differentiate tumors grow more rapidly
Local Invasion
- benign neoplasms remain localized to site of origin
- malignant tumors grow by progressive infiltration, invasion, destruction, and penetration
Metastasis
- secondary implants of a tumor that are discontinuous with the primary tumor and located in remote tissues
- the more anapestic and the larger the primary neoplasms, the more likely is metastatic spread
Cachexia
progressive loss of body fat and lean body mass accompanied by profound weakness, anorexia, and anemia
What causes cachexia
release of cytokines by the tumor or host
Paraneoplastic Syndromes
systemic symptoms that cannot be explained by tumor spread or by hormones appropriate to the tissue
What is paraneoplastic syndrome caused by
the ectopic production and secretion of bioactive substance such as ACTH, PTHrP, or TGF-alpha
ACTH
adrenocorticotropic hormone
Cushing syndrom
PTHrP
Parathyroid hormone related protein
PTHrP and TGF-alpha
hypercalcemia
6 Hallmarks of cancer
distinctive and complementary capabilities that enable tumor growth and metastatic dissemination
- Self-Sufficiency in growth signals
- insensitivity to anti-growth signals
- tissue invasion
- Limitless replicative potential
- Sustained Angiogenesis
- Evading Apoptosis
Self-sufficiency in growth signals
gene mutation allows for growth without stimulation from growth factor
Insensitivity to anti-growth signals
checkpoints in cell cycle bypassed due to oncogenes
Tissue invasion and metastasis
mutated proteins allows cells to escape from tissue into bloodstream and replant
Limitless replicative potential
due to up regulation of the enzyme of telomerase and inability for short tellers to be recognized and destroyed
Photo-oncogenes
- normally help cells grow
- mutated genes can become permanently activate when it is not supposed to be
- the cell grows out of control which can lead to cancer (now classified as an oncogene)
Tumor suppressor genes
- AKA anti-oncogenes
- normal genes that slow down cell division, repair DNA mistakes, or induce apoptosis
AIDS defining cancers
- kaposi sarcoma
- non-hodgkin lymphoma
- cervical cancer in women
Kaposi sarcoma
vascular tumor that was previously that most common neoplasm in AIDS before the introduction of anti-retroviral therapy
-causes aggressive lesions on the skin, mucus membranes, GI tracts
Non-hodgkin lymphoma
- second most common neoplasm in AIDS
- highly aggressive and is EBV related if the brain is involved
Cervical cancer in women
- attributed to the high incidence of HPV in patients with AIDS
- gynecological exam should be routine evaluation in HIV infected women
Non-AIDS defining cancers
- liver cancer
- anal cancer
- Hodgkin Lymphoma
Sustained angiogenesis
stimulates growth of new blood vessels by releasing protein hormones which are then used for oxygen and nutrients to grow
Evading apoptosis
tumor suppressed genes inhibited
accumulation of neoplastic cells is due to:
1) activation of growth-promoting oncogenes
2) inactivation of growth-suppressing tumor genes
3) mutations in the genes that regulate apoptosis
in a normal cell growth short telomeres are recognized by DNA repair machinery as Double stranded breaks , leading to
leading to cell cycle arrest and senescence
in 85% to 95% of cancers , this is due to upregulation of the enzyme
telomerase
5 laboratory diagnosis of cancer
1) Morphologic methods including excision, biopsy, fine-needle aspiration, and cytologic smears
2) Immunohistochemistry and flow cytometry studies
3) Tumor markers
4) Molecular analyses and diagnosis
5) Molecular profiling of tumors
2 clinical aspects of tumors
1) cachexia
2) paraneoplastic syndromes
cachexia
1) progressive loss of body fat and lean body mass
2) weakness
3) anorexia
4) anemia
5) caused by release of cytokines by the tumor or host
Paraneoplastic syndromes
1) systemic symptoms that cannot be explained by tumor spread or by hormones appropriate to the tissue
2) caused by ectopic production and secretion of bioactive substances such as ACTH, PTHrP, or TGF-α
In patients with cancer, calorie expenditure remains _____and basal metabolic rate is increased, despite reduced food intake. This is in contrast with the lower metabolic rate that occurs as an adaptive response in starvation.
high or low
high
In patients with cancer, calorie expenditure remains high, and basal metabolic rate is ________, despite reduced food intake. This is in contrast with the lower metabolic rate that occurs as an adaptive response in starvation.
increased or decreased
increased
In patients with cancer, calorie expenditure remains high, and basal metabolic rate is increased, despite ____, ______,_____. This is in contrast with the lower metabolic rate that occurs as an adaptive response in starvation.
increased food intake
reduced food intake
reduced food intake
tumor antigens are recognized by what type of T cells
cytotoxic T
and lymphocytes CTLs
what is the major immune defense mechanism against tumors
CTLs
Malignant neoplasms are characterized by a _______ of parenchymal cell differentiation
wide or narrow range
wide Range
anaplasia
lack of differentiation
4 characteristics of benign and malignant neoplasms
1) differentiation and anaplasia
2) rate of growth
3) local invasion
4) metastasis
what are the different types of tumor markers
PSA; CEA; Alpha fetal protein
all 3 protein (PSA, CEA, Alpha fetal protein) assays lack ______ and ______ required for early detection of cancers
specificity and sensitivity
H Pylori cause peptic ulcer disease in 20s and 30s patients, if got it have higher chance to get ___ cancer
gastric
MALT lymphomas
first bacterium classified as a carcinogen
when tumor suppressor genes don’t work properly, cells can grow out of control, which can lead to ____?
cancer
