In what ways can alterations in transport processes affect t

In what ways can alterations in transport processes affect the growth of tumors?

Solution

Transport in a biological system simply refers to the transport of solute across a membrane.

In the case of tumors, the high metabolic rate with altered transport processes which leads to increased uptake/transport of nutrients by the tumor cells. [This change in metabolic rate become the early indicators of malignancy as they produce more tumor markers.]

To study how this alteration affect growth of tumors invitro, virally transformed tumor cells was used. It has been concluded that due to surface alterations in the virally transformed tumor cells, the intracellular concentration of key metabolites varies which might lead to increased growth which again alters the surface property of tumor cells to affect the extent of growth. In the case of tumor cells extent of growth is increased at the expense of host machinery.

Let us study in detail how the change in carbohydrate transport affect the growth of a tumor.

In a transformed tumor cell, there is an increase in glucose transport which is due to growth related, transformation specific changes. It has been found that there is increased number of membrane-associated glucose transporters. The host may starve but tumor growth continues. Rarely lactate levels are elevated in cancer patients called lactic acidosis which is life threatening.

Other Metabolites such as lipids, aminoacids, proteins, enzymes and micronutrients such as vitamins and trace element transport is also altered in the case of tumor cells.

Scientists have also found that there is a relation between the degree of malignancy and loss of degradative enzymes involved in the transport of cations which have resulted in failure to maintain and regulate permeability. This leakiness results in altered permeability resulting in increasing the extent of growth.