Reducing tumor growth and angiogenesis using a triple therapy measured with Contrast-enhanced ultrasound (CEUS).

BACKGROUND: To evaluate the in vivo response by detecting the anti-angiogenic and invasion-inhibiting effects of a triple-combination-therapy in an experimental-small-animal-squamous-cell-carcinoma-model using the "flash-replenishment" (FR) method to assess tissue hemodynamics via contrast-enhanced-ultrasound (CEUS). METHODS: Human hypopharynx-carcinoma-cells were subcutaneously injected into the left flank of 22-female-athymic-nude-rats. After seven days of subcutaneous tumor growth, FR-measurements were performed on each rat. Treatment-group and control-group were treated every day for a period of one week, with the treatment-group receiving solvents containing a triple therapy of Upamostat®, Celecoxib® and Ilomastat® and the control-group solvents only. On day seven, follow-up measurements were performed using the same measurement protocol to assess the effects of the triple therapy. VueBox® was used to quantify the kinetic parameters and additional immunohistochemistry analyses were performed for comparison with and validation of the CEUS results against established methods (Proliferation/Ki-67, vascularization/CD31, apoptosis/caspase3). RESULTS: Compared to the control-group, the treatment-group that received the triple-therapy resulted in a reduction of tumor growth by 48.6% in size. Likewise, the immunohistochemistry results showed significant decreases in tumor proliferation and vascularization in the treatment-group in comparison to the control-group of 26%(p ≤ 0.05) and 32.2%(p ≤ 0.05) respectively. Correspondingly, between the baseline and follow-up measurements, the therapy-group was associated with a significant(p ≤ 0.01) decrease in the relative-Blood-Volume(rBV) in both the whole tumor(wt) and hypervascular tumor(ht) areas (p ≤ 0.01), while the control-group was associated with a significant (p ≤ 0.01) increase of the rBV in the wt area and a non-significant increase (p ≤ 0.16) in the ht area. The mean-transit-time (mTT) of the wt and the ht areas showed a significant increase (p ≤ 0.01) in the follow-up measurements in the therapy group. CONCLUSION: The triple-therapy is feasible and effective in reducing both tumor growth and vascularization. In particular, compared with the placebo-group, the triple-therapy-group resulted in a reduction in tumor growth of 48.6% in size when assessed by CEUS and a significant reduction in the number of vessels in the tumor of 32% as assessed by immunohistochemistry. As the immunohistochemistry supports the CEUS findings, CEUS using the "flash replenishment"(FR) method appears to provide a useful assessment of the anti-angiogenic and invasion-inhibiting effects of a triple combination therapy.

DCE-MRI biomarkers for monitoring an anti-angiogenic triple combination therapy in experimental hypopharynx carcinoma xenografts with immunohistochemical validation.

BACKGROUND: Novel anti-angiogenic treatments are increasingly complementing established cancer therapy strategies in head and neck tumors. Contrast-enhanced magnetic resonance imaging (MRI) can be applied for early and non-invasive therapy monitoring by non-invasive quantitative assessment of tumor microcirculation as in vivo imaging biomarkers of therapy response. PURPOSE: To monitor the anti-angiogenic effects of a novel combination therapy on experimental head and neck squamous cell carcinomas (HNSCC) with dynamic contrast-enhanced (DCE)-MRI. MATERIAL AND METHODS: Athymic rats (n = 18) with subcutaneous HNSCC xenografts were investigated by DCE-MRI before and after 7 days of a daily triple therapy regimen combining the COX-II-inhibitor celecoxib, the matrix-metalloproteinase-inhibitor GM6001, and the uPA-inhibitor upamostat. Quantitative measurements of tumor blood flow (tBF), tumor blood volume (tBV), and permeability-surface area product (PS) were calculated and validated by immunohistochemistry. RESULTS: Mean tBF and tBV in triple-therapy animals decreased significantly from day 0 to day 7 (tBF, 41.0 ± 14.2 to 20.4 ± 5.7 mL/100 mL/min; P < 0.01; tBV, 17.7 ± 3.9 to 7.5 ± 3.3%; P < 0.01). No significant effects on PS were observed in either group (P > 0.05). Immunohistochemical analysis showed a significantly lower tumor vascularity in the therapy group than in the control group (CD31), significantly fewer Ki-67+ proliferating tumor cells and significantly more Capase-3+ apoptotic tumor cells (P < 0.05). Significant (P < 0.05) correlations were observed between tBF/tBV and CD31 (tBF, r = 0.84; tBV, r = 0.70), tBV and Ki-67 (r = 0.62), as well as tBF and caspase-3 (r = -0.64). CONCLUSION: DCE-MRI may be a suitable tool for the non-invasive monitoring of the anti-vascular effects of this innovative triple therapy regimen with potential for clinical translation.