Despite recent advances in cancer treatment, the clinical outcome among NSCLC patients is not impressive. Our laboratory has been working with the use of inhalation and oral delivery of anticancer agents for treatment of lung cancer. Active targeting of chemotherapeutic drugs containing nanoparticles may effectively treat adenocarcinomas by achieving higher concentration at target sites. EphA2, an Eph family receptor tyrosine kinase is overexpressed in 90% of NSCLC tumors; high levels of EphA2 predicted poorer overall patient survival. Studies conducted in our laboratory have shown that H460 and A549 tumors express EphA2 receptors. Recently, the peptide, YSAYPDSVPMMS (YSA) has demonstrated to selectively bind to EphA2 receptors on lung and prostate cancer cells. Taking advantage of YSA peptide selective binding and overexpressed status of EphA2 receptors in lung cancer cells, we propose an YSA peptide conjugated NCs system to simultaneously and selectively deliver anticancer drugs to lung cancer tumors. However, irrespective of the targeting nature of the nanoparticles, their intratumoral distribution is hindeed by dense collagen network and highly fibrous interstitium. Use of antifibrotic agents has reported to decrease tumor interstitial fibrosis and promote nanoparticle intratumoral distribution. Recent studies have demonstrated that Losartan through transforming growth factor beta 1 (TGF-1) inhibition improved the penetration and therapeutic efficacy of drug loaded nanoparticles. Preliminary studies from our laboratory suggest that Telmisartan (AT1 blocker) produced 3 fold higher fibrolysis than Losartan. Therefore, it is expected that prior treatment with Telmisartan will make tumors lose their dense collagen network and will promote better intratumoral distribution of nanotherapeutics. We intend to treat the lung tumors with Telmisartan by inhalation and oral route prior to administering the NCs- Ds (Docetaxel containing nanoparticles) to solid lung tumors. We hypothesize that YSA conjugated targeted nanoparticles (NCs-D-Y) will selectively distribute, bind and actively internalize into the EphA2 over expressing lung cancer and tumor neovascular cells. This distribution will be facilitated by Telmisartan by its antifibrotc effects.
Our specific Aims are:
Specific Aim 1 : To prepare and evaluate various NC-D-Y formulations. In this aim we will prepare NCs-D conjugated with YSA peptide (NCs-D-Y) which shows evidence of specific targeting to the EphA2 receptors and inhibiting the growth of tumor cells in vitro.
Specific Aim 2 : In vivo Pharmacokinetic and Pharmacodynamic evaluation of NCs-F-Y and NCs-D-Y in orthotopic and metastatic tumors. In this aim, following Telmisartan treatment, the NCs-D-Y will be administered intravenously to lung tumor bearing animals for EphA2 specific targeted delivery. Telmisartan will make difficulty penetrable solid tumors into easily nanoparticle penetrable loose interstitial networks The results emanating from these studies will allow us to assess the role of Telmisartan in enhancing intratumoral delivery of targeted nanoparticles with their payloads of various chemotherapeutic drugs. The long term objectives of this proposal are to use the current approach to other fibrotic tumors and also with other nanoparticle payloads like siRNA, shRNA or small molecule anticancer drugs.
Cancer is a major global health problem, and each year in the US, approximately 571,950 people are diagnosed. The complex nature of tumors represents a significant challenge to the health care system. Development of target specific nanotherapeutics have offered new hope for cancer treatment, However, Poor penetration and heterogeneous distribution of therapeutics into tumors can be an important factor limiting their efficacy. The dense collagen network in tumors significantly reduces the penetration and efficacy of nanotherapeutics. The combinatorial approach for improved drug efficacy with tumor homing nanotherapeutics and anti-fibrotic drugs is likely to have a profound impact on cancer treatment.
