CFTR targeted therapies: recent advances in cystic fibrosis and possibilities in other diseases of the airways.

Cystic fibrosis transmembrane conductance regulator (CFTR) is an ion transporter that regulates mucus hydration, viscosity and acidity of the airway epithelial surface. Genetic defects in CFTR impair regulation of mucus homeostasis, causing severe defects of mucociliary clearance as seen in cystic fibrosis. Recent work has established that CFTR dysfunction can be acquired in chronic obstructive pulmonary disease (COPD) and may also contribute to other diseases that share clinical features of cystic fibrosis, such as asthma, allergic bronchopulmonary aspergillosis and bronchiectasis. Protean causes of CFTR dysfunction have been identified including cigarette smoke exposure, toxic metals and downstream effects of neutrophil activation pathways. Recently, CFTR modulators, small molecule agents that potentiate CFTR or restore diminished protein levels at the cell surface, have been successfully developed for various CFTR gene defects, prompting interest in their use to treat diseases of acquired dysfunction. The spectrum of CFTR dysfunction, strategies for CFTR modulation, and candidate diseases for CFTR modulation beyond cystic fibrosis will be reviewed in this manuscript.

Laryngeal actinomycosis in an immunocompromised patient.

Actinomycosis of the larynx represents an unusual presentation for a common bacterium comprising the oral and oropharyngeal florae. There are few cases reported in the literature of laryngeal actinomycosis occurring primarily in the immunocompromised population. Here, we present a case in a 74-year-old man that occurred in the setting of neutropenia as a result of chemotherapy. Once the diagnosis was made with biopsy of the larynx, the infection was resolved after a prolonged course of penicillin-based therapy.

Functional characterization of a fluorescent highly tumorigenic ovarian cancer line to test cellular therapy in experimental models.

OBJECTIVES: The objective of this study was to functionally characterize a fluorescent highly tumorigenic ovarian cancer line to test cellular therapy in combination with cytokines or chemotherapies in experimental models. METHODS: A fluorescent highly tumorigenic subline (SKOV3-AF2) was derived from the SKOV3 ovarian cancer cell line. Peripheral blood mononuclear cell (PBMC)-mediated cytotoxicity of SKOV3-AF2 in the presence of interleukin 2 (IL-2) and interferon α-2b (IFNα-2b) was assayed by lactate dehydrogenase release. Sensitivity of SKOV3-AF2 cells to polyethylene glycol-IFNα-2b and IL-2 was assayed in a xenograph nude mouse model. Histopathology was performed to determine necrosis and tumor-infiltrating lymphocytes in the solid tumors. Reverse transcriptase-polymerase chain reaction was used for gene expression analyses of E-cadherin and cysteine-rich 61 (CCN1). RESULTS: The SKOV3-AF2 subline exhibits increased cytotoxicity (up to 70%), mediated by PBMCs, IL-2, and IFNα-2b, compared with parental SKOV3-red fluorescent protein (RFP) cells. SKOV3-AF2 cells are more tumorigenic in vivo as indicated by tumor incidence, time to sacrifice, tumor weight, and ascitic fluid production. SKOV3-AF2 tumor growth was inhibited by polyethylene glycol-IFNα-2b but not low-dose IL-2. Histopathology revealed that the tumors consisted of poorly differentiated surface epithelial carcinoma. SKOV3-RFP, and -AF2 cell lines as well as -AF2 tumors expressed E-cadherin. SKOV3-AF2 derived tumors expressed CCN1; however, the SKOV3-RFP and SKOV3-AF2 cell lines did not. CONCLUSIONS: Characterization of SKOV3-AF2 cells revealed that it is more susceptible to PBMC-mediated cytotoxicity than SKOV3-RFP and highly tumorigenic in a xenograph model, and AF-2 tumors express genes that promote aggressive behavior. Collectively, our data suggest that the SKOV3-AF2 subline will be a useful tool to test cellular therapy for the treatment of ovarian cancer utilizing experimental models.

Synergistic cytotoxicity of interferonalpha-2b and interleukin-2 in combination with PBMC against ovarian cancer: development of an experimental model for cellular therapy.

OBJECTIVES: Current therapies for ovarian cancer (OC) patients have a modest impact on long-term survival justifying the need for novel treatment strategies. We developed in vitro and in vivo systems to test the effects of cytokines in combination with peripheral blood mononuclear cells (PBMC) on OC cells. METHODS: Two OC cell-lines were transfected with a plasmid encoding Red Fluorescent Protein (SKOV3-RFP and CAR3-RFP). Proliferation of these lines in the presence of cytokines alone and in combination was assayed. Cytotoxicity of SKOV3-RFP cells mediated by PBMC and cytokines was determined by lactate dehydrogenase release. Mice were injected intraperitoneally (IP) with SKOV3-RFP cells; solid tumor and ascitic fluid were collected, analyzed, and cell lines were established. Tumor-derived cell lines were re-injected to produce a more tumorigenic line. RESULTS: IFNalpha-2b showed an inhibitory effect on OC cell proliferation. The remaining cytokines, either alone or in combination, showed no significant effect. PBMC in combination with IL-2 showed clear dose-dependent cytotoxicity against SKOV3-RFP. IFNalpha-2b had a synergistic effect with IL-2 and PBMC increasing the cytotoxicity by an average of 20%. Using an animal model, SKOV3-RFP cells continue to express RFP when harvested from the peritoneum and are more tumorigenic when re-injected into mice. CONCLUSION: These observations justify the use of IL-2, IFNalpha-2b, and PBMC in a xenograph animal model of OC to determine if combination cytokine and cellular therapy has an anti-tumor effect in vivo. This approach may prove useful as an in vivo system of IP cytokines administered in combination with cellular therapy.