Abstract:
Cancer is one of the leading causes of death now-a-days. There are various treatment
options for cancer and each has its own side effects because most of the therapeutic
agents of cancer are non-selective and may cause destruction of both cancer as well as
normal cells. Therefore, search for a highly specific therapeutic molecule is still going
on. As it is known that, immune molecules are highly specific in terms of antigenantibody
reactions, so immunotherapy might be a better and more specific choice for
cancer therapy compared to conventional molecules in use. Moreover, to handle any
emergency cancer cases, there must be instant treatment option through passive
immunization. Surface protein antigenic similarity of a 64 kDa Mycobacterium bovis
BCG surface protein has been reported in the literature. BCG 64 kDa shares a
common 64 kDa antigenic determinant with various mouse and guinea pig cancer
cells and is cross reactive to one of these cancer cell antigens. The anti-BCG 64 kDa
antibody has also been shown to have anti-cancer effects against various solid tumors
of experimental animals having cross reactive antigen. However, there is no such
report of similar experiment on malignant ascites cell lines. Considering the above
facts, this study was undertaken to assess the effects of anti-64kDa antibody on
Ehrlich Ascites Carcinoma (EAC) cells. In this study, mouse anti-BCG 64 kDa
antibody showed anticancer effect on EAC cell, when compared to control. Animals
from experimental group showed increased life span and a plummeted rate of weight
gain than negative control. Animals transplanted with EAC cells were treated by two
methods. In one method, animals received regular treatment till day 7 and showed
49.2% increase in life span compared to negative control. The other method was
cyclic treatment (5 days, treatment, 5 days pause) where life span was increased up to
33.47% compared to negative control. Furthermore, reduced cell growth rate was
observed in EAC cell bearing mice treated with anti-BCG 64 kDa containing serum.
To confirm the cross reactivity between anti-BCG 64 kDa antibody and EAC cell
antigen, whole cell extracts of EAC cells were immunoblotted with BCG 64 kDa
immunized mice sera and a 64 kDa band was observed. All these data suggest us that,
water soluble BCG 64 kDa surface antigen shares common antigenic determinants
with malignant ascites cells and has anti-cancer activity in mice in terms of survival
and rate of weight gain. Considering all these results, we conclude that the anti-BCG
64 kDa antibody containing serum could be considered as an effective cancer
treatment option.
