Question

List the general cytologic, antigenic, metabolic, karyotypic, and molecular changes in neoplastic cells.

Answer 1

Neoplasm is the abnormal growth of cells. Neoplastic diseases are conditions that cause tumor growth, both benign and malignant.Benign tumors are noncancerous growths which grow slowly and cannot spread to other tissues. Malignant tumors are cancerous and can grow quickly or slowly.

Cytologic changes in tumour cells:

The following changes occurs in the cells

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• Increased nuclear size

• Pleomorphism- Variation in nuclear or cell size

• Anaplasia- Lack of differentiation

• Hyperchromatism- Increased nuclear DNA content with subsequent dark staining on H and E slides

• Prominent nucleoli or irregular chomatin distribution within nuclei.

• Irregular or bizarre mitoses.

Antigenic changes in Neoplasticism cells:

• Normal membrane antigens may be lost or new antigens gained.
• ABO blood group antigens may be lost in the case of human bronchus and bladdercancer. Shifts in ion ratios (Na+/K+/Ca++) within neoplastic cells may result in abnormalities in cell shape, cell movement, and cell-cell communication.
• Alterations in one or more components of the cytoskeleton may adversely affect cell shape, mobility of membrane proteins, cell-cell adhesion, etc., and play a major role in malignant cell behavior.

Metabolic changes in neoplastic cells:

• Altered metabolism is one of the hallmarks of cancer cells.
• The best-known metabolic abnormality in cancer cells is the Warburg effect, which demonstrates an increased glycolysis even in the presence of oxygen.
• Tumour-related metabolic abnormalities are not limited to altered balance between glucose fermentation and oxidative phosphorylation.
• Key tumor genes such as p53and c-myc are found to be master regulators of metabolism.

Karyotypic changes in neoplastic cells:

Karyotyping is the process by which photographs of chromosomes are taken in order to determine the chromosome complement of an individual, including the number of chromosomes and any abnormalities.

Chromosomal abnormalities occurs in all types of cancers.  Chromosome No. 13 was altered in only two tumors, but the aberrations in these two cases affected different portions of the chromosome. Every tumor showed trisomy of the long arm of either chromosome No. 1 or 17. These changes in chromosomes No. 1 and 17 have been observed by others in many different tumors and are not unique to retinoblastoma. chromosome abnormalities are not common to all tumors.

Metabolic changes in neoplastic cells:

It involves changes in genes which controls cell growth and replication.proto oncogenes, tumour suppressor genes,DNA repairing and genes for controlling apoptosis.Oncogenesis is a multifactorial event at molecular level.Oncogenesis promote growth of cancer cells derived from mutated proto oncogenes .