| Objective: The thyroid stimulating hormone(TSH)can promote cells growing and proliferation by up-regulating cyclic adenosine monophosphate(cAMP)concentration after combining to the thyroid stimulating hormone receptors(TSHR).Because TSHR can be expressed in papillary thyroid cancer(PTC)cells surface,the TSH may have the same effect on tumor cells,which is the basis of TSH suppression therapy.In this study,we injected different doses of TSH into the TPC tissue in nude mice and then we compared the volume and cAMP concentration of the tumors.We want to investigate the effects of TSH on PTC and the way it works,as well as the relation and significance among TSH,cAMP concentration and tumor volume.Methods: The TPC cells(TPC-1)were subcultured.Thirty-five naked male mice(four-week-old)were divided randomly into seven groups(five mice in each group).TPC-1 was subcutaneously injected(the dose of 1×106 /ml)on back and neck.Since the day after the TPC-1 injection,different doses of TSH were started to be injected(0 mU/L,2 mU/L,4 mU/L,8 mU/L,12 mU/L,16 mU/L,20 mU/L,respectively)at the same injecting point once every other day.Sixteen days later,all mice were killed and the tumor size were measured to calculate the volume(V=1/2×length×width×height).The cAMP concentration of tumor tissues were measured by enzyme-linked immunosorbent assay(ELLSA)and adjusted by protein.The data was analyzed by SPSS 13.0 software.Results: All mice in every group were survival during the test time and had the visible TPC tumors on the back and neck.No accident were occured,such as worrying each other,ulceration of tumors,infection and so on.Comparing PTC tumor volume among groups,there was a significant difference among groups(P<0.05).When comparing every two groups,the tumor volume between group one and two had no statistical difference(P>0.05).While,the other groups had statistic difference(P < 0.05).The correlation coefficient of TSH and tumor volume was statistically positive(r=0.990,P<0.01).Comparing cAMP concentration of the tumor tissues among groups,there was a significant difference(P<0.05).When comparing every two groups,no statistic difference had been found between group five and six(P>0.05).While the others had differences(P<0.05).The correlation coefficient of TSH and cAMP volume was positive(r=0.883,P<0.01).There was a significantly positive relation between cAMP and tumor volume(r=0.927,P<0.01).Conclusion:1 TSH may promote the proliferation of PTC.The higher TSH dose is,the larger tumor volume is.2 Under a certain dose,the proliferation of TSH on PTC-1 is not so obvious,which may has the reference value of TSH suppression therapy.3 The cAMP concentration in PTC tissues is positively related to TSH.It is suggested that TSH works by up-regulating cAMP concentration.4 There is a positive relation between cAMP concentration and tumor volume.The cAMP may promote the proliferation of tumor. |
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