A survey about the effect of immune response raised by Leishmania major on fibrosarcoma tumor in Balb/c mice

Previous investigations and available data demonstrate that there are different patterns of diseases distribution in developed and developing countries. While in developed countries the major cause of death are cancers, in developing countries the main cause of death are infectious diseases. Various factors may be responsible for different causes of death in two those groups of countries. There are raising scientific evidences that some infectious and parasitic organisms when enter the body may effect the tumor growth. In order to explore this presumption, in this work the effect of Leishmania major infection on fibrosarcoma tumor growth in mouse model has been investigated. In this experimental study a group of inbred mice (n=6) were infected with Leishmania major as case group. After one month both these mice and some more mice as control group (n=6) were challenged with fibrosarcoma cells. The size of growing solid tumors was measured in individual mouse every two days up to two weeks. This measurement was performed 5 times on days 5, 7, 11, 13 and 16. Tumor area was also calculated for every single mouse. T-test was used to analyze data. Results of this work showed that the mean size of tumor in case group was smaller than that of control group only in the first week following challenge with fibrosarcoma cells but the tumor mass was bigger in days 13 and 16 in case group. However the difference between the tumor mass in case and control groups was not statistically significant. Results of this investigation revealed that there was no significant difference between the tumor mass in case and control mice. However to explore more about the hypothesis of this study, it is recommended that the research work be carried out using different tissue parasites and also different cell lines.