MOLECULAR BASIS OF CANCER
Characteristics of cancer cells
(1) High rate of cell division
(2) Genome instability (increased rate of accumulation of mutations)
(3) Replicative immortality (reactivation of telomerase genes maintains telomere lengths; allows
cancer cells to evade apoptosis)
(4) Anchorage-independent growth (proliferate without attachment to surface)
(5) Lack of contact inhibition and density-dependent inhibition
(6) Inducing angiogenesis (formation of new blood vessels)
(7) Metastasis (establishment of secondary tumours at distant sites)
(8) Evading immune destruction
Benign vs Malignant tumours
● Abnormal/uncontrolled growth of cells/tissue
Benign tumour Malignant tumour
Nature Few genetic mutations, do not Invasive and cancerous, may
cause serious health problems impair functions of organs
Treatment Can be removed by surgery Radiation/chemotherapy
Nuclear size and shape Cells have small and regular Cells have large and irregular
nucleus nucleus
Nuclear/cytoplasmic volume Cells have low N/C ratio Cells have high N/C ratio
(N/C) ratio
Rate of mitosis Low High
Differentiation Well-differentiated, retains most Poorly differentiated, do not
structural features from resemble parental cells;
parental cells dedifferentiation may have
occurred
Tumour boundary Well-defined Poorly defined
Cells remain clustered together Cells may or may not cluster
in a single mass in a localised together, able to metastasise
region with a well-defined and form secondary tumours
perimeter; unable to (metastases) at distant sites
metastasise
Cell cycle and cancer
● Coordinates the division, differentiation and death of cells via cell cycle checkpoints
Copyright © 2019 tonyndr
Characteristics of cancer cells
(1) High rate of cell division
(2) Genome instability (increased rate of accumulation of mutations)
(3) Replicative immortality (reactivation of telomerase genes maintains telomere lengths; allows
cancer cells to evade apoptosis)
(4) Anchorage-independent growth (proliferate without attachment to surface)
(5) Lack of contact inhibition and density-dependent inhibition
(6) Inducing angiogenesis (formation of new blood vessels)
(7) Metastasis (establishment of secondary tumours at distant sites)
(8) Evading immune destruction
Benign vs Malignant tumours
● Abnormal/uncontrolled growth of cells/tissue
Benign tumour Malignant tumour
Nature Few genetic mutations, do not Invasive and cancerous, may
cause serious health problems impair functions of organs
Treatment Can be removed by surgery Radiation/chemotherapy
Nuclear size and shape Cells have small and regular Cells have large and irregular
nucleus nucleus
Nuclear/cytoplasmic volume Cells have low N/C ratio Cells have high N/C ratio
(N/C) ratio
Rate of mitosis Low High
Differentiation Well-differentiated, retains most Poorly differentiated, do not
structural features from resemble parental cells;
parental cells dedifferentiation may have
occurred
Tumour boundary Well-defined Poorly defined
Cells remain clustered together Cells may or may not cluster
in a single mass in a localised together, able to metastasise
region with a well-defined and form secondary tumours
perimeter; unable to (metastases) at distant sites
metastasise
Cell cycle and cancer
● Coordinates the division, differentiation and death of cells via cell cycle checkpoints
Copyright © 2019 tonyndr
