Autophagy and enhanced chemosensitivity in experimental pancreatic cancers induced by noninvasive radiofrequency field treatment.

Background: Patients with pancreatic ductal adenocarcinoma (PDAC) have limited therapeutic options and poor response to the standard gemcitabine (GCB)-based chemotherapy. In the current study, the authors investigated the feasibility of noninvasive short-wave radiofrequency (RF) electric fields to improve the cytotoxic effect of GCB on PDAC cells and determined its mechanism of action.

Methods: The cytotoxicity of RF alone and in combination with GCB was studied in vitro on normal pancreatic human pancreatic ductal epithelial cells and different PDAC cell lines by flow cytometry, and in vivo on ectopic and orthotopic human PDAC xenograft models in mice.

Silencing thioredoxin induces liver cancer cell senescence under hypoxia.

Aim:   Although thioredoxin 1 (TXN) has pleiotropic cellular functions as a redox-sensitive protein, very little is known about its role in tumor survival and growth under hypoxia. MHCC97H hepatocellular carcinoma cells have a high metastatic potential and high thioredoxin expression levels compared with their parent cell line, MHCC97. Thus, we used this cell line to explore the functional connections between TXN and hypoxia.

Stability of antibody-conjugated gold nanoparticles in the endolysosomal nanoenvironment: implications for noninvasive radiofrequency-based cancer therapy.

Unlabelled: The use of noninvasive radiofrequency (RF) electric fields as an energy source for thermal activation of nanoparticles within cancer cells could be a valuable addition to the emerging field of nano-mediated cancer therapies. Based on investigations of cell death through hyperthermia, and offering the ability for total-body penetration by RF fields, this technique is thought to complement and possibly outperform existing nano-heat treatments that utilize alternative heat production via optical or magnetic stimuli. However, it remains a challenge to understand fully the complex RF-nanoparticle-intracellular interactions before full system optimization can be engineered.

Noninvasive radiofrequency field-induced hyperthermic cytotoxicity in human cancer cells using cetuximab-targeted gold nanoparticles.

Shortwave (MHz range) radiofrequency (RF) energy is nonionizing, penetrates deeply into biologic tissues with no adverse side effects, and heats gold nanoparticles efficiently. Targeted delivery of gold nanoparticles to cancer cells should result in hyperthermic cytotoxicity upon exposure to a focused, noninvasive RF field. In this report we demonstrate that gold nanoparticles conjugated with cetuximab (C225) are quickly internalized by Panc-1 (pancreatic adenocarcinoma) and Difi (colorectal adenocarcinoma) cancer cells overexpressing epidermal growth factor receptor (EGFR).

An orthotopic model of papillary thyroid carcinoma in athymic nude mice.

Objective: To develop a reproducible orthotopic model of papillary thyroid carcinoma for the BRAF(V600E) mutation (GenBank NM004333) and an RET/PTC rearrangement (GenBank M31213) that recapitulates the clinical picture in humans.

Design: In vitro and in vivo study.

Setting: Department of Head and Neck Surgery, M.

Headpin: a serpin with endogenous and exogenous suppression of angiogenesis.

Headpin is a novel serine proteinase inhibitor (serpin) with constitutive mRNA expression in histologically normal oral mucosa but with lost or down-regulated expression in head and neck squamous cell carcinoma. Several serpin family members are similarly lost in multiple cancer types and hold tumor suppressor functions including the inhibition of angiogenesis. However, the functional significance for the loss of headpin expression in cancer is not known.

Consequences of C-terminal domains and N-terminal signal peptide deletions on LEKTI secretion, stability, and subcellular distribution.

The secretory lympho-epithelial Kazal-type-inhibitor (LEKTI) is synthesized as a pro-LEKTI protein containing an N-terminal signal peptide and 15 potentially inhibitory domains. This inhibitor is of special interest because of its pathophysiological importance for the severe congenital disease Netherton syndrome. We showed that LEKTI is a potent inhibitor of a family of serine proteinases involved in extracellular matrix remodeling and its expression is downregulated in head and neck squamous cell carcinomas.

Expression of LEKTI domains 6-9' in the baculovirus expression system: recombinant LEKTI domains 6-9' inhibit trypsin and subtilisin A.

The precursor lympho-epithelial Kazal-type-related inhibitor (LEKTI), containing two Kazal-type and 13 nonKazal-type domains, is an efficient inhibitor of multiple serine proteinases, among them plasmin, subtilisin A, cathepsin G, elastase, and trypsin. To gain insight into the structure and function of some of these domains, a portion of the cDNA coding for LEKTI domains 6-9' was cloned and expressed in Sf9 cells using the baculovirus expression vector system (BEVS). Through a single purification step using a Co2+ column, 3-4 mg of purified recombinant LEKTI-domains 6-9' (rLEKTI6-9') with the predicted molecular mass of 34.

Resetting the histone code at CDKN2A in HNSCC by inhibition of DNA methylation.

Head and neck squamous cell carcinoma (HNSCC) is the fifth most frequent cancer in the US. Several genetic and epigenetic alterations are associated with HNSCC tumorigenesis, including inactivation of CDKN2A, which encodes the p16 tumor suppressor, in cell lines and primary tumors by DNA methylation. Reactivation of tumor suppressor genes by DNA-demethylating agents and histone deacetylase (HDAC) inhibitors shows therapeutic promise for other cancers.