Non-cell metastasis of malignant tumor: A preliminary experiment

The present study aimed to investigate the non-cell metastasis of malignant tumor (metastasis at the molecular level). Primers for the specific SPY gene of male mouse were designed and used to detect the SPY gene in the Lewis lung cancer (LLC) cells by PCR; LLC cells were inoculated into females C57BL/6 mice. H and E staining was performed to detect the subcutaneous primary tumor and metastatic tumors in the lungs and liver, and polymerase chain reaction (PCR) and In situ hybridization (ISH) were employed to detect the sex determining region of the Y (SRY) gene in the primary and metastatic tumors. After inoculation of LLC cells carrying SRY gene into female C57BL/6 mice, the SRY gene was detectable in the metastatic tumor in these female mice, which suggests the metastatic cancer cells originate from the primary tumor. Our results demonstrated the metastasis of cancer cells at the cellular level but not the non-cell metastasis. It is very difficult to verify the "hypothesis of non-cell metastasis" by animal experiment for the limit of itself. Further studies with new strategies are required to elucidate our hypothesis due to the presence of limitations in the present study.