Exosomes in lung cancer: actors and heralds of tumor development

Simple Summary Lung cancer is a leading cause of cancer-related death worldwide and in most cases, detection is usually late and treatment resistance is frequent. For that reason, it is necessary to find biomarkers that could improve the diagnosis and disease management. Exosomes are a type of microvesicles secreted by tumor cells to the medium, with important functions in tumor development. Their analysis can be of utility in diagnosis, including early diagnosis, prognosis, treatment election or follow-up. However, isolation and analysis are cumbersome and can affect the subsequent data information. In this review, we will discuss the recent advances in the role of exosomes in lung cancer and their utility as liquid biopsy, with special attention to isolating methods. Lung cancer is a leading cause of cancer-related death worldwide and in most cases, diagnosis is reached when the tumor has already spread and prognosis is quite poor. For that reason, the research for new biomarkers that could improve early diagnosis and its management is essential. Exosomes are microvesicles actively secreted by cells, especially by tumor cells, hauling molecules that mimic molecules of the producing cells. There are multiple methods for exosome isolation and analysis, although not standardized, and cancer exosomes from biological fluids are especially difficult to study. Exosomes' cargo proteins, RNA, and DNA participate in the communication between cells, favoring lung cancer development by delivering signals for growth, metastasis, epithelial mesenchymal transition, angiogenesis, immunosuppression and even drug resistance. Exosome analysis can be useful as a type of liquid biopsy in the diagnosis, prognosis and follow-up of lung cancer. In this review, we will discuss recent advances in the role of exosomes in lung cancer and their utility as liquid biopsy, with special attention to isolating methods

Utility of recombinant human TSH stimulation test in the follow-up of patients with differentiated thyroid cancer depending on basal thyroglobulin results

Background: Thyroglobulin (Tg) is fundamental for differentiated thyroid cancer (DTC) monitoring. Tg detection can be enhanced using recombinant human thyroidstimulating hormone (TSH) (rhTSH). This study is aimed to evaluate the use of the rhTSH stimulation test when using a high-sensitivity Tg assay. Methods: We retrospectively studied 181 rhTSH tests from 114 patients with DTC and negative for antithyroglobulin antibodies (anti-TgAb). Image studies were performed in all cases. Serum Tg and anti-TgAb were measured using specific immunoassays. Results: rhTSH stimulation in patients with basal serum Tg (b-Tg) concentrations lower than 0.2 ng/mL always resulted in rhTSH-stimulated serum Tg (s-Tg) concentrations lower than 1.0 ng/mL and negative structural disease. In patients with bTg concentration between 0.2 and 1.0 ng/mL, s-Tg detected one patient (1/30) who showed biochemical incomplete response. Patients with negative images had lower s-Tg than thosewith nonspecific or abnormal findings (p<0.05).Receiver operating characteristic curve analysis of the s-Tg to detect altered images showed an area under the curve of 0.763 (p<0.05).With an s-Tg cutoff of 0.85 ng/mL, the sensitivity was 100%, decreasing to 96.15% with an s-Tg cutoff of 2 ng/mL. Conclusions: Patients with DTC with b-Tg concentrations equal or higher than 0.2 ng/mL can benefit from the rhTSH stimulation test

PSA reactivity in extracellular microvesicles to commercial immunoassays

Aims: Characterization of PSA in extracellular microvesicles (EVs) and its reactivity to commercial methods. Materials and methods: EVs derived from serum of 47 prostate cancer (PCa) patients, 27 benign prostatic hyperplasia (BPH) patients and 42 healthy controls were analyzed. EVs isolation and quantification of PSA immunoreactive to total (ev-T-PSA) or free (ev-F-PSA) PSA immunoassays, were performed using commercial assays. PSA in CD81+ or CD63+ EVs was determined directly in serum by an immunocapture-ELISA (IC-ELISA). Results: Ev-T-PSA immunoreactive to Elecsys assay was detected in all samples. Median T-PSA ev/srm ratio was 2.20 % (Q1-Q3: 0.80-4.00 %), although in some samples this ratio reached 59 %. T-PSA ev/srm ratio was higher in those samples with serum T-PSA below 4 µg/L than in those exceeding that cut-off (p < 0.001). T-PSA ev/srm ratio was lower in PCa patients compared to healthy controls and BPH patients (p < 0.001). Elecsys immunoassays detected higher concentrations of ev-T-PSA and ev-F-PSA than Immulite (p < 0.001). PSA was detected by IC-ELISA more intensely in CD81+ EVs than in CD63+ EVs, and ev-T-PSA correlated with PSA+ CD63+ (p < 0.001) but not with PSA+ CD81+. Conclusion: EVs-bound PSA is another form of circulating PSA whose measurement could be easily performed in clinical laboratories by automated immunoassays

Utility of recombinant human TSH stimulation test in the follow-up of patients with differentiated thyroid cancer depending on basal thyroglobulin results

Background: Thyroglobulin (Tg) is fundamental for differentiated thyroid cancer (DTC) monitoring. Tg detection can be enhanced using recombinant human thyroidstimulating hormone (TSH) (rhTSH). This study is aimed to evaluate the use of the rhTSH stimulation test when using a high-sensitivity Tg assay. Methods: We retrospectively studied 181 rhTSH tests from 114 patients with DTC and negative for antithyroglobulin antibodies (anti-TgAb). Image studies were performed in all cases. Serum Tg and anti-TgAb were measured using specific immunoassays. Results: rhTSH stimulation in patients with basal serum Tg (b-Tg) concentrations lower than 0.2 ng/mL always resulted in rhTSH-stimulated serum Tg (s-Tg) concentrations lower than 1.0 ng/mL and negative structural disease. In patients with bTg concentration between 0.2 and 1.0 ng/mL, s-Tg detected one patient (1/30) who showed biochemical incomplete response. Patients with negative images had lower s-Tg than thosewith nonspecific or abnormal findings (p<0.05).Receiver operating characteristic curve analysis of the s-Tg to detect altered images showed an area under the curve of 0.763 (p<0.05).With an s-Tg cutoff of 0.85 ng/mL, the sensitivity was 100%, decreasing to 96.15% with an s-Tg cutoff of 2 ng/mL. Conclusions: Patients with DTC with b-Tg concentrations equal or higher than 0.2 ng/mL can benefit from the rhTSH stimulation test

Utility of recombinant human TSH stimulation test in the follow-up of patients with differentiated thyroid cancer depending on basal thyroglobulin results

Background: Thyroglobulin (Tg) is fundamental for differentiated thyroid cancer (DTC) monitoring. Tg detection can be enhanced using recombinant human thyroidstimulating hormone (TSH) (rhTSH). This study is aimed to evaluate the use of the rhTSH stimulation test when using a high-sensitivity Tg assay. Methods: We retrospectively studied 181 rhTSH tests from 114 patients with DTC and negative for antithyroglobulin antibodies (anti-TgAb). Image studies were performed in all cases. Serum Tg and anti-TgAb were measured using specific immunoassays. Results: rhTSH stimulation in patients with basal serum Tg (b-Tg) concentrations lower than 0.2 ng/mL always resulted in rhTSH-stimulated serum Tg (s-Tg) concentrations lower than 1.0 ng/mL and negative structural disease. In patients with bTg concentration between 0.2 and 1.0 ng/mL, s-Tg detected one patient (1/30) who showed biochemical incomplete response. Patients with negative images had lower s-Tg than thosewith nonspecific or abnormal findings (p<0.05).Receiver operating characteristic curve analysis of the s-Tg to detect altered images showed an area under the curve of 0.763 (p<0.05).With an s-Tg cutoff of 0.85 ng/mL, the sensitivity was 100%, decreasing to 96.15% with an s-Tg cutoff of 2 ng/mL. Conclusions: Patients with DTC with b-Tg concentrations equal or higher than 0.2 ng/mL can benefit from the rhTSH stimulation test

MAPK inhibitors dynamically affect melanoma release of immune NKG2D-ligands, as soluble protein and extracellular vesicle-associated

Metastatic melanoma presents, in many cases, oncogenic mutations in BRAF, a MAPK involved in proliferation of tumour cells. BRAF inhibitors, used as therapy in patients with these mutations, often lead to tumour resistance and, thus, the use of MEK inhibitors was introduced in clinics. BRAFi/MEKi, a combination that has modestly increased overall survival in patients, has been proven to differentially affect immune ligands, such as NKG2D-ligands, in drug-sensitive vs. drug-resistant cells. However, the fact that NKG2D-ligands can be released as soluble molecules or in extracellular vesicles represents an additional level of complexity that has not been explored. Here we demonstrate that inhibition of MAPK using MEKi, and the combination of BRAFi with MEKi in vitro, modulates NKG2D-ligands in BRAF-mutant and WT melanoma cells, together with other NK activating ligands. These observations reinforce a role of the immune system in the generation of resistance to directed therapies and support the potential benefit of MAPK inhibition in combination with immunotherapies. Both soluble and EV-associated NKG2D-ligands, generally decreased in BRAF-mutant melanoma cell supernatants after MAPKi in vitro, replicating cell surface expression. Because potential NKG2D-ligand fluctuation during MAPKi treatment could have different consequences for the immune response, a pilot study to measure NKG2D-ligand variation in plasma or serum from metastatic melanoma patients, at different time points during MAPKi treatment, was performed. Not all NKG2D-ligands were equally detected. Further, EV detection did not parallel soluble protein. Altogether, our data confirm the heterogeneity between melanoma lesions, and suggest testing several NKG2D-ligands and other melanoma antigens in serum, both as soluble or vesicle-released proteins, to help classifying immune competence of patients