The Nanotechnology-Based Approaches against Kirsten Rat Sarcoma-Mutated Cancers.

Kirsten rat sarcoma (KRAS) is a small GTPase which acts as a molecular switch to regulate several cell biological processes including cell survival, proliferation, and differentiation. Alterations in KRAS have been found in 25% of all human cancers, with pancreatic cancer (90%), colorectal cancer (45%), and lung cancer (35%) being the types of cancer with the highest mutation rates. KRAS oncogenic mutations are not only responsible for malignant cell transformation and tumor development but also related to poor prognosis, low survival rate, and resistance to chemotherapy. Although different strategies have been developed to specifically target this oncoprotein over the last few decades, almost all of them have failed, relying on the current therapeutic solutions to target proteins involved in the KRAS pathway using chemical or gene therapy. Nanomedicine can certainly bring a solution for the lack of specificity and effectiveness of anti-KRAS therapy. Therefore, nanoparticles of different natures are being developed to improve the therapeutic index of drugs, genetic material, and/or biomolecules and to allow their delivery specifically into the cells of interest. The present work aims to summarize the most recent advances related to the use of nanotechnology for the development of new therapeutic strategies against KRAS-mutated cancers.

Impact of Chemical Composition on the Nanostructure and Biological Activity of α-Galactosidase-Loaded Nanovesicles for Fabry Disease Treatment.

Fabry disease is a rare lysosomal storage disorder characterized by a deficiency of α-galactosidase A (GLA), a lysosomal hydrolase. The enzyme replacement therapy administering naked GLA shows several drawbacks including poor biodistribution, limited efficacy, and relatively high immunogenicity in Fabry patients. An attractive strategy to overcome these problems is the use of nanocarriers for encapsulating the enzyme. Nanoliposomes functionalized with RGD peptide have already emerged as a good platform to protect and deliver GLA to endothelial cells. However, low colloidal stability and limited enzyme entrapment efficiency could hinder the further pharmaceutical development and the clinical translation of these nanoformulations. Herein, the incorporation of the cationic miristalkonium chloride (MKC) surfactant to RGD nanovesicles is explored, comparing two different nanosystems-quatsomes and hybrid liposomes. In both systems, the positive surface charge introduced by MKC promotes electrostatic interactions between the enzyme and the nanovesicles, improving the loading capacity and colloidal stability. The presence of high MKC content in quatsomes practically abolishes GLA enzymatic activity, while low concentrations of the surfactant in hybrid liposomes stabilize the enzyme without compromising its activity. Moreover, hybrid liposomes show improved efficacy in cell cultures and a good in vitro/in vivo safety profile, ensuring their future preclinical and clinical development.

Expression and Role of MicroRNAs from the miR-200 Family in the Tumor Formation and Metastatic Propensity of Pancreatic Cancer.

MicroRNAs from the miR-200 family are commonly associated with the inhibition of the metastatic potential of cancer cells, following inhibition of ZEB transcription factors expression and epithelial-to-mesenchymal transition. However, previous studies performed in pancreatic adenocarcinoma revealed a more complex picture challenging this canonical model. To gain better insights into the role of miR-200 family members in this disease, we analyzed the expression of miR-200a, miR-200b, miR-200c, miR-141, miR-429, and miR-205, and ZEB1, ZEB2, and CDH1 in pancreatic tumors and matching normal adjacent parenchyma and patient-derived xenografts. We found that miR-200a, miR-429, and miR-205 are frequently overexpressed in pancreatic tumors, whereas CDH1 is downregulated, and ZEB1 and ZEB2 levels remain unchanged. Furthermore, we measured a positive correlation between miR-200 family members and CDH1 expression, and a negative correlation between ZEB1 and miR-200c, miR-141, and miR-205 expression, respectively. Interestingly, we identified significant changes in expression of epithelial-to-mesenchymal transition regulators and miR-200 members in patient-derived xenografts. Lastly, functional studies revealed that miR-141 and miR-429 inhibit the tumorigenic potential of pancreatic cancer cells. Taken together, this comprehensive analysis strongly suggests that miRNAs from the miR-200 family, and in particular miR-429, may act as a tumor suppressor gene in pancreatic cancer.

APC promoter is frequently methylated in pancreatic juice of patients with pancreatic carcinomas or periampullary tumors.

Early detection of pancreatic and periampullary neoplasms is critical to improve their clinical outcome. The present authors previously demonstrated that DNA hypermethylation of adenomatous polyposis coli (APC), histamine receptor H2 (HRH2), cadherin 13 (CDH13), secreted protein acidic and cysteine rich (SPARC) and engrailed-1 (EN-1) promoters is frequently detected in pancreatic tumor cells. The aim of the present study was to assess their prevalence in pancreatic juice of carcinomas of the pancreas and periampullary area. A total of 135 pancreatic juices obtained from 85 pancreatic cancer (PC), 26 ampullary carcinoma (AC), 10 intraductal papillary mucinous neoplasm (IPMN) and 14 chronic pancreatitis (CP) patients were analyzed. The methylation status of the APC, HRH2, CDH13, SPARC and EN-1 promoters was analyzed using methylation specific-melting curve analysis (MS-MCA). Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations were also tested with allele-specific quantitative polymerase chain reaction amplification. Out of the 5 promoters analyzed, APC (71%) and HRH2 (65%) were the most frequently methylated in PC juice. APC methylation was also detected at a high frequency in AC (76%) and IPMN (80%), but only occasionally observed in CP (7%). APC methylation had a high sensitivity (71-80%) for all types of cancer analyzed. The panel (where a sample scored as positive when ≥2 markers were methylated) did not outperform APC as a single marker. Finally, KRAS detection in pancreatic juice offered a lower sensitivity (50%) and specificity (71%) for detection of any cancer. APC hypermethylation in pancreatic juice, as assessed by MS-MCA, is a frequent event of potential clinical usefulness in the diagnosis of pancreatic and periampullary neoplasms.