Toward fully exploiting the therapeutic potential of marketed pharmaceuticals: the use of octreotide and chloroquine in oncology

Lysosomotropic Features and Autophagy Modulators among Medical Drugs: Evaluation of Their Role in Pathologies

The concept of lysosomotropic agents significantly changed numerous aspects of cellular biochemistry, biochemical pharmacology, and clinical medicine. In the present review, we focused on numerous low-molecular and high-molecular lipophilic basic compounds and on the role of lipophagy and autophagy in experimental and clinical medicine. Attention was primarily focused on the most promising agents acting as autophagy inducers, which offer a new window for treatment and/or prophylaxis of various diseases, including type 2 diabetes mellitus, Parkinson's disease, and atherosclerosis. The present review summarizes current knowledge on the lysosomotropic features of medical drugs, as well as autophagy inducers, and their role in pathological processes.

A randomized, double-blind, window of opportunity trial evaluating the effects of chloroquine in breast cancer patients

PURPOSE

Chloroquine has demonstrated anti-tumor activities through autophagy inhibition and cell cycle disruption. This study aimed to assess the effect of single-agent chloroquine on breast tumor cellular proliferation in a randomized, phase II, double-blind, placebo-controlled, pre-surgical window of opportunity trial.

METHODS

Patients with newly diagnosed breast cancer were randomized 2:1 to chloroquine 500 mg daily or placebo for 2- to 6-weeks prior to their breast surgery. The primary outcome was the relative change in measures of proliferation (Ki67) in primary breast cancer cells pre- and post-treatment. Adverse events and toxicity profiles were also evaluated.

RESULTS

From September 2015 to December 2016, 70 patients were randomized [46 (66%) chloroquine and 24 (34%) placebo]. Ten patients who were randomized to chloroquine withdrew from study due to adverse events. Mean duration of drug intake was 15 days (range 14-29 days). There were no significant differences between the chloroquine or placebo arms with respect to either the percentage change (- 0.4 vs. - 1.2, p = 0.088) or absolute change (- 2.0% vs. - 5.2%, p = 0.066) in Ki67 index pre- and post-drug treatment. Although adverse effects were minimal and all classified as grade 1, the effects were significant enough to cause nearly 15% of patients to discontinue therapy.

CONCLUSIONS

Treatment with single-agent chloroquine 500 mg daily in the preoperative setting was not associated with any significant effects on breast cancer cellular proliferation. It was, however, associated with toxicity that may affect its broader use in oncology.

Octreotide Nanoparticles Showed Affinity for In Vivo MIA Paca-2 Inducted Pancreas Ductal Adenocarcinoma Mimicking Pancreatic Polypeptide-Secreting Tumor of the Distal Pancreas (PPoma)

PURPOSE

Pancreatic Polypeptide-secreting tumor of the distal pancreas (PPoma) is a rare, difficult and indolent type of cancer with a survival rate of 5-year in only 10% of all cases. The PPoma is classified as a neuroendocrine tumor (NET) not functioning that overexpresses SSTR 2 (somatostatin receptor subtype 2). Thus, in order to improve the diagnosis of this type of tumor, we developed nanoparticulate drug carriers based on poly-lactic acid (PLA) polymer loaded with octreotide and radiolabeled with Technetium-99 m (99mTc).

METHODS

PLA/PVA octreotide nanoparticles were developed by double-emulsion technique. These nanoparticles were characterized by Atomic Force Microscopy (AFM) and Dynamic Light Scattering (DLS) and radiolabeled with 99mTc by the direct via forming 99mTc-PLA/PVA octreotide nanoparticles. The safety of these nanosystems was evaluated by the MTT cell toxicity assay and their in vivo biodistribution was evaluated in xenografted inducted animals.

RESULTS

The results showed that a 189 nm sized nanoparticle were formed with a PDI of 0,097, corroborating the monodispersive behavior. These nanoparticles were successfully radiolabeled with 99mTc showing uptake by the inducted tumor. The MTT assay corroborated the safety of the nanosystem for the cells.

CONCLUSION

The results support the use of this nanosystem (99mTc-PLA/PVA octreotide nanoparticles) as imaging agent for PPoma. Graphical Abstract Polypeptide-Secreting Tumor of the Distal Pancreas (PPoma) Radiolabeled Nanoparticles for Imaging.