29 research outputs found
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
Nitric oxide produces HLA-G nitration and induces metalloprotease-dependent shedding creating a tolerogenic milieu
Human leucocyte antigen G (HLA-G) is a tolerogenic molecule that protects the
fetus from maternal immune attack, may favour tumoral immunoescape and is
up-regulated in viral and inflammatory diseases. The aim of this work was to
discover if nitric oxide (NO) could affect HLA-G expression or function because
NO is an important modulator of innate and adaptive immunity. For this purpose
HLA-G expression and function were analysed following treatment with a NO donor
or a peroxynitrite donor in various cell lines expressing HLA-G either
spontaneously or upon transfection. Results showed NO-dependent nitration of both
cellular and soluble HLA-G protein, but not all HLA-G moieties underwent
nitration. Endogenous biosynthesis of NO by both U-937-HLA-G1 and M8-HLA-G5
stable transfectants also caused HLA-G nitration. The NO decreased total HLA-G
cellular protein content and expression on the cell surface, while increasing
HLA-G shedding into the culture medium. This effect was post-transcriptional and
the result of metalloprotease activity. By contrast, NO pretreatment did not
affect HLA-G capability to suppress NK cytotoxicity and lymphocyte proliferation.
Our studies show that NO regulates the availability of HLA-G molecules without
modifying their biological activities
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
Clinical implications of changing thyroglobulin and antithyroglobulin antibodies analytical methods in the follow-up of patients with differentiated thyroid carcinoma
Background and aims: Patientsâ response to treatment in differentiated thyroid cancer (DTC) is classified according to serum thyroglobulin concentrations (Tg), usually using the American Thyroid Association guidelines
and considering potential interfering anti-thyroglobulin antibodies (Ab-Tg). We aim to evaluate the clinical
implications of changing Tg and Ab-Tg quantification method.
Material and methods: Tg and Ab-Tg were quantified in 82 serum samples (60 from DTC patients) by Elecsys and
Access immunoassays.
Results: Elecsys immunoassay rendered higher values of Tg than Access: mean bias 5.03 ng/mL (95%CI:-
14.14â24.21). In DTC patients, there was an almost perfect agreement for response classification (kappa index =
0.833). Discrepancies appeared in patients with undetermined response, with a more tendency to subclassification with Access. Ab-Tg showed a poor correlation (r = 0.5394). When Elecsys cut-off was reduced to 43 IU/
mL, agreement for positive/negative classification improved from a kappa index of 0.607 to 0.650. Prospective
study with personalized follow-up showed that only 6.3% of Tg results required an analytical confirmation, being
confirmed 93% of them.
Conclusions: Despite the biases observed, clinical impact of an analytical change is minimal in patientsâ management. However, cautious and personalized follow-up period after the change is still mandatory, especially in
patients with Tg levels between 0.2 and 1 ng/mL
Linking Two Immuno-Suppressive Molecules: Indoleamine 2,3 Dioxygenase Can Modify HLA-G Cell-Surface Expression1
Nonclassical human leukocyte antigen (HLA) class I molecule
HLA-G and indoleamine 2,3 dioxygenase (INDO) in humans and
mice, respectively, have been shown to play crucial immunosuppressive
roles in fetal-maternal tolerance. HLA-G inhibits
natural killer and T cell function by high-affinity interaction with
inhibitory receptors, and INDO acts by depleting the surrounding
microenvironment of the essential amino acid tryptophan,
thus inhibiting T cell proliferation. We investigated whether
HLA-G expression and INDO function were linked. Working
with antigen-presenting cell (APC) lines and monocytes, we
found that functional inhibition of INDO by 1-methyl-tryptophan
induced cell surface expression of HLA-G1 by HLA-G1-
negative APCs that were originally cell-surface negative, and
that in reverse, the functional boost of INDO by high concentrations
of tryptophan induced a complete loss of HLA-G1 cell
surface expression by APCs that were originally cell-surface
HLA-G1-positive. This mechanism was shown to be posttranslational
because HLA-G protein cell contents remained unaffected
by the treatments used. Furthermore, HLA-G cell surface
expression regulation by INDO seems to relate to INDO function,
but not to tryptophan catabolism itself. Potentia
The dynamic use of EGFR mutation analysis in cell-free DNA as a follow-up biomarker during different treatment lines in non-small-cell lung cancer patients
Epidermal growth factor receptor (EGFR) mutational testing in advanced non-small-cell lung cancer (NSCLC) is usually performed
in tumor tissue, although cfDNA (cell-free DNA) could be an alternative. We evaluated EGFR mutations in cfDNA as a
complementary tool in patients, who had already known EGFR mutations in tumor tissue and were treated with either
EGFR-tyrosine kinase inhibitors (TKIs) or chemotherapy. We obtained plasma samples from 21 advanced NSCLC patients with
known EGFR tumor mutations, before and during therapy with EGFR-TKIs and/or chemotherapy. cfDNA was isolated and
EGFR mutations were analyzed with the multiple targeted cobas EGFR Mutation Test v2. EGFR mutations were detected at
baseline in cfDNA from 57% of patients. The semiquantitative index (SQI) significantly decreased from the baseline
(median = 11, IQR = 9 5-13) to the best response (median = 0, IQR = 0-0, p < 0 01), followed by a significant increase at
progression (median = 11, IQR = 11-15, p < 0 01) in patients treated with either EGFR-TKIs or chemotherapy. The SQI obtained
with the cobas EGFR Mutation Test v2 did not correlate with the concentration in copies/mL determined by droplet digital
PCR. Resistance mutation p.T790M was observed at progression in patients with either type of treatment. In conclusion, cfDNA
multiple targeted EGFR mutation analysis is useful for treatment monitoring in tissue of EGFR-positive NSCLC patients
independently of the drug received
Multimeric structures of HLA-G isoforms function through differential binding to LILRB receptors
The non-classical Human leukocyte antigen G (HLA-G) differs from classical HLA class I molecules by its low genetic diversity, a tissue-restricted expression, the existence of seven isoforms, and immuno-inhibitory functions. Most of the known functions of HLA-G concern the membrane-bound HLA-G1 and soluble HLA-G5 isoforms, which present the typical structure of classical HLA class I molecule: a heavy chain of three globular domains α(1)-α(2)-α(3) non-covalently bound to ÎČ-2-microglobulin (B2M) and a peptide. Very little is known of the structural features and functions of other HLA-G isoforms or structural conformations other than B2M-associated HLA-G1 and HLA-G5. In the present work, we studied the capability of all isoforms to form homomultimers, and investigated whether they could bind to, and function through, the known HLA-G receptors LILRB1 and LILRB2. We report that all HLA-G isoforms may form homodimers, demonstrating for the first time the existence of HLA-G4 dimers. We also report that the HLA-G α(1)-α(3) structure, which constitutes the extracellular part of HLA-G2 and HLA-G6, binds the LILRB2 receptor but not LILRB1. This is the first report of a receptor for a truncated HLA-G isoform. Following up on this finding, we show that the α(1)-α(3)-Fc structure coated on agarose beads is tolerogenic and capable of prolonging the survival of skin allografts in B6-mice and in a LILRB2-transgenic mouse model. This study is the first proof of concept that truncated HLA-G isoforms could be used as therapeutic agents
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 ”g/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