Size-Transformable Bicomponent Peptide Nanoparticles for Deep Tumor Penetration and Photo-Chemo Combined Antitumor Therapy

The suitable size of multifunctional nanomedicines strongly influences their physicochemical properties and actions in biological systems, for example, prolonged blood circulation time, efficient tumor accumulation, and deep tumor penetration. However, it is still a great challenge to construct size-transformable nanoparticles (NPs) for both efficient accumulation and penetration throughout tumor tissue. Herein, a size-transformed multifunctional NP is developed through a simple bicomponent assembling strategy for enhanced tumor penetration and efficient photo-chemo combined antitumor therapy, due to the acidic tumor microenvironment and near infrared-laser irradiation induced size-shrink. This multifunctional bicomponent NP (PP NP) driven by electrostatic interaction is composed of negatively charged peptide amphiphile (PA1) and positively charged peptide prodrug (PA2). PP NPs (≈170 nm) have been proven to improve blood circulation time and stability in biological environments. Interestingly, PP NPs can reassemble small NPs (<30 nm) by responding to acidic tumor microenvironment and near-infrared laser irradiation, which facilitates deep tumor penetration and improves cellular internalization. By integrating fluorescence imaging, tumor targeting, deep tumor penetration, and combined photo-chemotherapy, PP NPs exhibit excellent in vivo antitumor efficacy. This study might provide an insight for developing a bicomponent assembling system with efficient tumor penetration and multimode for antitumor therapy.

Carrier-Free, Dual-Functional Nanorods Via Self-Assembly Of Pure Drug Molecules For Synergistic Chemo-Photodynamic Therapy

BACKGROUND

The combination of chemo-photodynamic therapy based on nano-technology has emerged as a preferable and promising measure for synergetic antitumor therapy.

PURPOSE

The aim of this study was expected to overcome most of the safety concerns from nano-carriers and improve the chemo-photodynamic synergistic antitumor efficacy.

METHODS

Herein, we reported a facile and effective approach based on the self-assembly of chemotherapeutic agent 10-hydroxycamptothecin (HCPT) and photosensitizer chlorin e6 (Ce6) for preparing stably dual-functional nanorods (NRs).

RESULTS

The chemical thermodynamic parameters obtained from isothermal titration calorimeter (ITC) and the microcosmic configuration snapshots acquired by molecular dynamics (MD) simulations verified that HCPT and Ce6 molecules tended to assemble with each other through various intermolecular forces. The as-prepared HCPT/Ce6 NRs possessed a relatively uniform size of around 165 nm and zeta potential of about -29 mV, together with good stability in aqueous solution and freeze-dried state. In addition, both the extra- and intracellular reactive oxygen species (ROS) generation capacity of the NRs under laser irradiation was significantly enhanced compared with Ce6 injections. Moreover, the dual-functional HCPT/Ce6 NRs exhibited a substantial in vitro/in vivo synergistic antitumor efficacy under laser irradiation due to the integration of the two therapeutic modalities into one drug delivery system. Besides, no obvious hepatic or renal toxicity was observed in the NRs treatment groups.

CONCLUSION

Taken together, HCPT/Ce6 NRs demonstrated a powerful efficacy in chemo-photodynamic therapy for breast cancer. Therefore, the carrier-free dual-functional NRs prepared in a facile and effective strategy might give inspiration for the development of combined antitumor therapy.

Discovery and optimization of cardenolides inhibiting HSF1 activation in human colon HCT-116 cancer cells

Combinational anticancer therapy demonstrates increased efficiency, as it targets different cell-survival mechanisms and allows the decrease of drug dosages that are often toxic to normal cells. Inhibitors of the heat shock response (HSR) are known to reduce the efficiency of proteostasis mechanisms in many cancerous cells, and therefore, may be employed as anti-tumor drug complements. However, the application of HSR inhibitors is limited by their cytotoxicity, and we suggested that milder inhibitors may be employed to sensitize cancer cells to a certain drug. We used a heat-shock element-luciferase reporter system and discovered a compound, CL-43, that inhibited the levels of heat shock proteins 40, 70 (Hsp70), and 90 kDa in HCT-116 cells and was not toxic for cells of several lines, including normal human fibroblasts. Consequently, CL-43 was found to reduce colony formation and motility of HCT-116 in the appropriate assays suggesting its possible application in the exploration of biology of metastasizing tumors. Importantly, CL-43 elevated the growth-inhibitory and cytotoxic activity of etoposide, cisplatin, and doxorubicin suggesting that the pro-drug has broad prospect for application in a variety of anti-tumor therapy schedules.

Dynamic changes in circulating miRNA levels in response to antitumor therapy of lung cancer

PURPOSE

Expression levels of cancer-associated microRNAs were reported to be altered in serum/plasma samples from lung cancer patients compared with healthy subjects. The purpose of this study was to estimate the value of five selected miRNAs plasma levels as markers of response to antitumor therapy in lung cancer patients.

MATERIALS AND METHODS

Expression levels of miR-19b, miR-126, miR-25, miR-205, and miR-125b have been evaluated by quantitative reverse transcription PCR versus control miR-16 in blood plasma samples from 23 lung cancer (LC) patients. Plasma samples were obtained from LC patients before treatment (untreated-UT), within 30 days after completing two courses of chemotherapy (postchemotherapy-PC) and 15 days after surgery (postoperative-PO).

RESULTS

Repeated Measures ANOVA demonstrated that miR-19b expression levels were decreased in PC and increased in PO samples. These changes were characterized by a significant quadratic trend (p = 0.03). Expression levels of miR-125b increased both after chemotherapy and again after surgery and demonstrated a significant linear trend (p = 0.03). The miR-125b/miR-19b ratio changed during the course of the antitumor treatment with a significant linear trend (p = 0.04). Individual analysis in the groups of patients with partial response to chemotherapy and patients with stable or progressive disease showed different trends for miR-19b, miR-125b, and miR-125b/miR-19b ratio between the groups. The Kaplan-Meier survival curves demonstrated an association of miR-125b/miR-19b ratio value with the survival time without the tumor relapse (p < 0.1).

CONCLUSIONS

Dynamic change of trends for miR-19b and miR-125b expression levels and miR-125b/miR-19b ratio in the blood plasma have shown a potentiality to discriminate types of response to antitumor therapy in lung cancer patients. Further in-depth investigation is needed to establish a direct link the miRNAs expression levels in blood plasma with therapy response and patient's survival.