Objective: To observe the in vivo inhibition effects of tumor necrosis factor-alpha (TNF-alpha) gene transduced tumor drainage node of lymphocytes (DNL) from tongue cancer on SCID mice transplanted tumor.
Methods: 15 human tongue carcinoma models were established in SCID mice by subcutaneously injection of squamous cell carcinoma line Tca8113. TNF-alpha gene introduced DNL, combined with low dose Pinyancin (PYC), were locally injected into tumor site. The inhibition rate was determined by the weights at the 8th week after tumor dissection and fresh specimens were prepared and subject to histopathologic examination under transmission electron microscope, and in situ TUNEL was used to detect apoptosis.
Results: The TNF/DNL and rIL-2 group, and the TNF/DNL and rIL-2 and PYC group both exerted a strong inhibition effect on the implanted tumor. Treated tumors of the TNF/DNL and rIL-2 and PYC group were significantly reduced in comparison with those of the TNF/DNL and rIL-2 group (P < 0.05). The apoptosis of tumor in the TNF/DNL and rIL -2 group was evidenced based on transmission electron microscope and TUNEL analysis, and the apoptosis index was higher than that of control group (P < 0.05).
Conclusion: Local injection of DNL modified with TNF-alpha gene, combined with low dose PYC, exert a synergistic antitumor effect. Apoptosis may be an important mechanism of squamous cell carcinoma killed by TNF/DNL.