The major stress-inducible Hsp70 (HSPA1A) is overexpressed in the cytosol of many highly aggressive tumor cells including glioblastoma multiforme and presented on their plasma membrane. Depending on its intracellular or membrane localization, Hsp70 either promotes tumor growth or serves as a target for NK cells. The kinetics of the membrane Hsp70 (mHsp70) density on human glioma cells (U87) was studied after different irradiation doses to define the optimal therapeutic window for Hsp70-targeting NK cells. To maintain the cells in the exponential growth phase during a cultivation period of 7 days different initial cell counts were seeded. Although cytosolic Hsp70 levels remained unchanged on days 4 and 7 after a sublethal irradiation with 2 Gy, 4 Gy and 6 Gy, a dose of 2 Gy resulted in an upregulated mHsp70 density in U87 cells which peaks on day 4 and starts to decline on day 7. Higher radiation doses (4 Gy, 6 Gy) resulted in an earlier and more rapid onset of the mHsp70 expression on days 2 and 1, respectively, followed by a decline on day 5. Membrane Hsp70 levels are higher in G2/M than in G1, however, an irradiation-induced cell cycle arrest on days 4 and 7, was not associated with an increase in the mHsp70 density. Extracellular Hsp70 concentrations increased significantly compared to sham (0 Gy) irradiated cells on days 4 and 7 but not on day 1. Functionally, elevated mHsp70 densities were associated with a significantly better lysis by Hsp70-targeting NK cells. In summary, the kinetics of changes in the mHsp70 density upon irradiation on tumor cells is time- and dose-dependent.

In the follow-up of treated high-grade cervical intraepithelial neoplasia (HSIL/CIN) lesions, cer-vical cytology has a high false-negative rate, while high-risk human papillomavirus (HR-HPV) DNA testing showed high sensitivity and lower specificity. The detection of messenger RNA of the HR-HPV E6 and E7 oncoproteins (E6/E7 mRNA) seems to be an indicator of viral integration and it allows the identification of severe lesions. Our objective was to assess the clinical utility of E6/E7 mRNA determination in the follow-up of patients treated for HSIL/CIN. A retrospective obser-vational study including 407 patients treated for HSIL/CIN was performed. The recurrence rate and the validity of E6/E7 mRNA testing were evaluated. The recurrence rate of high-grade lesions was 1.7%. The sensitivity of the test was 88% in the first clinical revision and 100% in the second and third revisions. Specificity was 91% in the first revision, 92% in the second revision, and 85% in the third revision. The positive predictive value was 18% in the first medical revision, 10% in the second and 14% in the third. The negative predictive value was 100% in all follow-up visits. In conclusion, the E6/E7 mRNA test seems to be effective in ruling out recurrence after treatment for HSIL/CIN lesions.