PARP1 and small cell lung carcinoma: To test wheter the effects of Omomyc on SCLC cells were a consequence of the specific inhibition of the MYC pathway, MYC expression in Lu135omo cells was suppressed using a siRNA for MYC. The amounts of p21 and p27, as well as the percentage of cleaved PARP1, were increased in Lu135omo cells by MYC knockdown (Figure 5A).