Cancer is a genetic disease:
– Inherited cancer – Sporadic cancer • Cancer typically involves a change in gene expression/function: – Qualitative change – Quantitative change • Any cancer causing genetic alteration typically results in loss of cell growth control.
What is Cancer? Malignant Vs. Benign growth
• Benign: called a tumor – Well circumscribed, slow growing, noninvasive, nonmetastatic. • Malignant: called a cancer – Not well organized, irregularly shaped, fast growing, infiltrative growth, metastatic. • Initial stages of malignant cancer may typically show benign growth; – further accumulation of mutations may make it malignant.
Properties of Cancer Cells
• Cancer cells exhibit several characteristics that are distinct from normal cells. • Multiple changes are involved in the conversion of a normal cell to a cancer cell: – Autocrine stimulation; grow in the absence of growth factors – Lack of gap junctions; – lack of contact inhibition – Resistance to cell death; persistent telomerase activity – Rapid growth; overtake population, invade other tissues. – Angiogenesis – Clonal nature of cancer – Genomic Instability: Accumulation of successive mutations • A germline mutation causes a hereditary cancer. • A somatic mutation causes a sporadic cancer.
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