Synthesis of PEGylated methotrexate conjugated with a novel CPP6, in sillico structural insights and activity in MCF-7 cells

Prediction of Drug Synergism between Peptides and Antineoplastic Drugs Paclitaxel, 5-Fluorouracil, and Doxorubicin Using In Silico Approaches

Chemotherapy is the main treatment for most early-stage cancers; nevertheless, its efficacy is usually limited by drug resistance, toxicity, and tumor heterogeneity. Cell-penetrating peptides (CPPs) are small peptide sequences that can be used to increase the delivery rate of chemotherapeutic drugs to the tumor site, therefore contributing to overcoming these problems and enhancing the efficacy of chemotherapy. The drug combination is another promising strategy to overcome the aforementioned problems since the combined drugs can synergize through interconnected biological processes and target different pathways simultaneously. Here, we hypothesized that different peptides (P1-P4) could be used to enhance the delivery of chemotherapeutic agents into three different cancer cells (HT-29, MCF-7, and PC-3). In silico studies were performed to simulate the pharmacokinetic (PK) parameters of each peptide and antineoplastic agent to help predict synergistic interactions in vitro. These simulations predicted peptides P2-P4 to have higher bioavailability and lower T_max, as well as the chemotherapeutic agent 5-fluorouracil (5-FU) to have enhanced permeability properties over other antineoplastic agents, with P3 having prominent accumulation in the colon. In vitro studies were then performed to evaluate the combination of each peptide with the chemotherapeutic agents as well as to assess the nature of drug interactions through the quantification of the Combination Index (CI). Our findings in MCF-7 and PC-3 cancer cells demonstrated that the combination of these peptides with paclitaxel (PTX) and doxorubicin (DOXO), respectively, is not advantageous over a single treatment with the chemotherapeutic agent. In the case of HT-29 colorectal cancer cells, the combination of P2-P4 with 5-FU resulted in synergistic cytotoxic effects, as predicted by the in silico simulations. Taken together, these findings demonstrate that these CPP6-conjugates can be used as adjuvant agents to increase the delivery of 5-FU into HT-29 colorectal cancer cells. Moreover, these results support the use of in silico approaches for the prediction of the interaction between drugs in combination therapy for cancer.

PEGylation and Cell-Penetrating Peptides: Glimpse into the Past and Prospects in the Future

Several drug molecules have shown low bioavailability and pharmacokinetic profile due to metabolism by enzymes, excretion by the renal system, or due to other physiochemical properties of drug molecules. These problems have resulted in the loss of efficacy and the gain of side effects associated with drug molecules. PEGylation is one of the strategies to overcome these pharmacokinetic issues and has been successful in the clinic. Cell-penetrating Peptides (CPPs) help to deliver molecules across biological membranes and could be used to deliver cargo selectively to the intracellular site or to the drug target. Hence CPPs could be used to improve the efficacy and selectivity of the drug. However, due to the peptidic nature of CPPs, they have a low pharmacokinetic profile. Using PEGylation and CPPs together as a component of a drug delivery system, the and efficacy of drug molecules could be improved. The other important pharmacokinetic properties such as short half-life, solubility, stability, absorption, metabolism, and elimination could be also improved. Here in this review, we summarized PEGylated CPPs or PEGylation based formulations for CPPs used in a drug delivery system for several biomedical applications until August 2019.

Breast cancer: insights in disease and influence of drug methotrexate

According to the World Health Organization, cancer is one of the leading causes of morbidity and mortality worldwide. The previously estimated 14 million new cases in the year of 2012 are expected to rise, yearly, over the following 2 decades. Among women, breast cancer is the most common one. In 2012, almost 1.7 million people were diagnosed worldwide and half a million died from the disease. Despite having several treatments available, from surgery to chemotherapy, most of these treatments have severe adverse effects. Chemotherapy has a narrow therapeutic window and requires high dosage treatment in patients with advanced-stage cancers and further need innovative treatment strategies. Although methotrexate (MTX) is not a first line drug used against breast cancer, however, it might be valuable to fight the disease. MTX is an effective and cheap drug that might impair malignant growth without irreversible damage to normal tissues. Nevertheless, while MTX does present some disadvantages including poor solubility and low permeability, several strategies are being used to discover and provide novel and effective targeted treatment against breast cancer. In this review, we analyze the chemotherapy of breast cancer and its relationship with drug MTX.