Abstract C43: Cancer effects on the function of the host immune organs: Thymus and spleen
Authors: Xu Jie , Xu Ze , Zhu Shiping , Tovanich Sitthipol , Wu Bin 
Published: May 2019

Objective: To investigate cancer effects on the function of the host immune organs: Thymus and Spleen

Methods: 40 Kunming mice and divided into four groups at random: control group of healthy mice; inoculated group with 0.1*107 ehrlich ascites carcinoma through abdominal cavity, executed them after 3 days; inoculated group with 0.1*107 ehrlich ascites carcinoma, executed them after 7 days; inoculated group with 0.1*107 ehrlich ascites carcinoma, executed them after 14 days. Executed the mice of each group and reserved the whole blood of each mouse to do lymphocyte conversion and then anatomized them immediately; observed the range of soakage, volume of ascites and the situation of all viscera; emphasized on observing the anatomical shape of thymus, spleens and lymph nodes and took out the thymus and spleen integrally, then measured their volume with a vernier caliper; weigh them respectively using analytical balance.

Results: 1.Thymuses weights: within 7 days after inoculation, thymuses have no obvious change observed by eyes; however their weights begin to lose weight. After 7 days, they present acute progressive atrophy; in the later period, the diameter of the thymuses reduces from the normal level 5~8 mm to about 1mm and the weights decrease from 76.1mg to 20mg with the texture becoming hard and the functions declining even lost, which indicates that the cellular immune functions are operated and inhibited increasingly with the development of tumors, and the immune functions are declined to a lower level with tumors growing more and more rapidly.

2. Spleen weights: spleens of cancer- bearing mice in the early stage the volume is enlarging gradually and the weight is increasing, while in the later stage, the spleens present progressive atrophy.

3. The change in lymphocyte conversion rate of the cancer-bearing mice presents certain regularity: after inoculation the conversion rate increase slightly and then presents an acute progressive decrease. Until 14th day (later period), it declines to normal level about 50% and continue declining after that, which indicates that in the whole course of diseases, cancer cells produce inhibitory effect on the cellular immunity; with the course of diseased this effect becomes more intensive and the immune functions are damaged. The changes in thymic volume and weight are extremely similar to the curve of lymphocyte conversion rate presented as synchronism. By contrast, the changes in splenic volume and weight are different from them with increase in the early period and the decrease, which indicates that during the middle and later period, both the organismal humoral immunity and cellular immunity are damaged and inhibited.

4. Changes of thymic and splenic pathology

(1) Thymus presents progressive atrophy during the whole course of disease; on the 3rd day after inoculated with cancer cells, thymus shrinks slightly and the color is gray; on the 7th day, thymic volume shrinks obviously and the cellular proliferation is stopped with reduced mature cells; during the later period of cancers, thymus shrinks extremely and its volume is as big as a sesame with the diameter of 1 mm and hard texture.

(2) Spleen is congested and tumefied; the volume is augmenting with being black red and crisp. The number of germinal centers increase and mature decrease; while from the 14th day after inoculation, spleen also presents progressive atrophy.

Conclusion:

1. Cancer effect on Thymus: Cancer cells inhibit the function of Thymus, the cell proliferation inhibited, the mature cell decrease or loss, the metabilish decrease, the cell activities decrease, the decrease of the secretory of thymus hormones, the cell-mediated immune function was damaged and the defense of the mice decrease, cancer cells of transplantation grow rapidly.

2. Cancer effect on Spleen: 1) cancer cells active the immune response to kill cancer cells through cancer cell specific antigen which can stimulate the host immune system to protect our body. 2). cancer can induce the suppressor cells and inhibiting factor production, and add the inhibiting factors from the tumor cell secretion to inhibit the immune system anticancer in the host to escape the immune surviellence and to survive and to develop. When cancer cells enter into the body in the early stage, the spleen will be stimulated to produce the reactions and the cell proliferation faster and function stronger and produce more immune effective cells and lymphokines and inhibit cancer growth. In the later stage, along with cancer development, cancer cells produce lots of the immune inhibiting factors which lead to the spleen shrinkle and the immune function will be limited or damaged so that the spleen lost the positive function of the anticancer immune responses.

Citation Format: Jie Xu, Ze Xu, Shiping Zhu, Sitthipol Tovanich, Bin Wu. Cancer effects on the function of the host immune organs: Thymus and spleen. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr C43.