Up to 20%-30% of patients with metastatic non-medullary thyroid cancer have persistent or recurre... more Up to 20%-30% of patients with metastatic non-medullary thyroid cancer have persistent or recurrent disease resulting from tumor dedifferentiation. Tumor redifferentiation to restore sensitivity to radioactive iodide (RAI) therapy is considered a promising strategy to overcome RAI resistance. Autophagy has emerged as an important mechanism in cancer dedifferentiation. Here, we demonstrate the therapeutic potential of autophagy activators for redifferentiation of thyroid cancer cell lines. Five autophagy-activating compounds, all known as digitalis-like compounds, restored hNIS expression and iodide uptake in thyroid cancer cell lines. Upregulation of hNIS was mediated by intracellular Ca 2þ and FOS activation. Cell proliferation was inhibited by downregulating AKT1 and by induction of autophagy and p21-dependent cellcycle arrest. Digitalis-like compounds, also designated as cardiac glycosides for their well-characterized beneficial effects in the treatment of heart disease, could therefore represent a promising repositioned treatment modality for patients with RAI-refractory thyroid carcinoma. Mol Cancer Ther; 16(1); 169-81.
Differentiated thyroid cancer (DTC) is the most frequent endocrine tumor with a good prognosis af... more Differentiated thyroid cancer (DTC) is the most frequent endocrine tumor with a good prognosis after primary treatment in most cases. By contrast, 30–40% of patients with metastatic DTC are unresponsive to 131I radioactive iodide (RAI) treatment due to tumor dedifferentiation. Currently, underlying molecular mechanisms of dedifferentiation remain elusive and predictive biomarkers are lacking. Therefore, the present study aimed to identify molecular biomarkers in primary tumors associated with RAI refractoriness. A retrospective cohort was gathered consisting of RAI-sensitive patients with DTC and RAI-refractory patients with poorly DTC. In all patients, extensive intratumoral mutation profiling, gene fusions analysis, telomerase reverse transcriptase (TERT) promoter mutation analysis and formalin-fixed paraffin-embedded-compatible RNA sequencing were performed. Genetic analyses revealed an increased mutational load in RAI-refractory DTC, including mutations in AKT1, PTEN, TP53 and T...
4498 Dectin-1 is a C-type lectin receptor that recognizes b-1,3-glucan, and plays an important ro... more 4498 Dectin-1 is a C-type lectin receptor that recognizes b-1,3-glucan, and plays an important role in antifungal immunity. The recently discovered dectin-1 Y238X polymorphism, which results in “loss-of-function” has been shown associated with increased Candida colonization of stem cell transplantation (SCT) recipients. Besides its role in antifungal immunity Dectin-1 exhibits a broader function in immunity. Stimulation of Dectin-1 with β-glucan affects antigen presentation, modulates T-lymphocytic (CD4+, both Th1 and Th17, and CD8+) and B-lymphocytic responses, and induces cytokine production including interleukin (IL) 10, IL-12 and IL-23. These specific T-cell responses and cytokines are of particular interest in SCT because they are involved in graft-versus-leukemia (GvL) effects as well as in the pathogenesis of graft-versus-host disease (GvHD). Therefore we now performed a retrospective study in 140 patients on the impact of the Y238X polymorphism on the outcome of myeloablativ...
The intracellular proinflammatory mediator IL-32 is associated with tumor progression; however, t... more The intracellular proinflammatory mediator IL-32 is associated with tumor progression; however, the mechanisms remain unknown. We studied IL-32 mRNA expression as well as expression of other proinflammatory cytokines and mediators, including IL-1α, IL-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, the proangiogenic and antiapoptotic enzyme cyclooxygenase-2, the IL-8 receptor C-X-C chemokine receptor (CXCR) 1, and the intracellular kinase focal adhesion kinase-1. The interaction of IL-32 expression with expression of IL-6, TNF-α, IL-8, and cyclooxygenase-2 was also investigated. Biopsy specimens of 11 HIV-related, 7 non-HIV-related Kaposi sarcoma (KS), and 7 normal skin tissues (NSTs) of Dutch origin were analyzed. RNA was isolated from the paraffin material, and gene expression levels of IL-32 α, β, and γ isoforms, IL1a, IL1b, IL6, IL8, TNFA, PTGS2, CXCR1, and PTK2 were determined using real-time quantitative PCR. Significantly higher expression of IL-32β and IL-32γ isoforms was obs...
Objective: To analyze changes in fat cell size, macrophage infiltration, and local adipose tissue... more Objective: To analyze changes in fat cell size, macrophage infiltration, and local adipose tissue adipokine profiles in different fat depots in patients with active Cushing's syndrome. Methods: Subcutaneous (SC) and perirenal (PR) adipose tissue of 10 patients with Cushing's syndrome was compared to adipose tissue of 10 gender-, age-, and BMI-matched controls with regard to adipocyte size determined by digital image analysis on hematoxylin and eosin stainings, macrophage infiltration determined by digital image analysis on CD68 stainings, and adipose tissue leptin and adiponectin levels using fluorescent bead immunoassays and ELISA techniques. Results: Compared to the controls, mean adipocyte size was larger in PR adipose tissue in patients. The percentage of macrophage infiltration of the PR adipose tissue and PR adipose tissue lysate leptin levels were higher and adiponectin levels were lower in SC and PR adipose tissue lysates in patients. The adiponectin levels were also lower in the SC adipose tissue supernatants of patients. Associations were found between the severity of hypercortisolism and PR adipocyte size. Conclusions: Cushing's syndrome is associated with hypertrophy of PR adipocytes and a higher percentage of macrophage infiltration in PR adipose tissue. These changes are associated with an adverse local adipokine profile.
The NF-κB inflammatory pathway plays a major role in cancer development and clinical progression.... more The NF-κB inflammatory pathway plays a major role in cancer development and clinical progression. Activation of NF-κB signaling is promoted by NFKB1 and inhibited by NFKBIA. The present study aimed to determine the relevance of NFKB1 rs4648068 and NFKBIA rs2233406 genetic variants for non-medullary thyroid cancer (NMTC) susceptibility, progression and clinical outcome. This case–control and cohort study consists of a Romanian discovery cohort (157 patients and 258 controls) and a Dutch validation cohort (138 patients and 188 controls). In addition, patient cohorts were analyzed further for the association of genetic variants with clinical parameters. Functional studies were performed on human peripheral blood mononuclear cells. No associations were observed between the studied genetic variants and TC susceptibility. Although no statistically significant associations with clinical parameters were observed for NFKB1 rs4648068, the heterozygous genotype of NFKBIA rs2233406 was correlat...
The great majority of thyroid cancers are of the non-medullary type. Here we report findings from... more The great majority of thyroid cancers are of the non-medullary type. Here we report findings from a genome-wide association study of non-medullary thyroid cancer, including in total 3,001 patients and 287,550 controls from five study groups of European descent. Our results yield five novel loci (all with Pcombined<3 × 10(-8)): 1q42.2 (rs12129938 in PCNXL2), 3q26.2 (rs6793295 a missense mutation in LRCC34 near TERC), 5q22.1 (rs73227498 between NREP and EPB41L4A), 10q24.33 (rs7902587 near OBFC1), and two independently associated variants at 15q22.33 (rs2289261 and rs56062135; both in SMAD3). We also confirm recently published association results from a Chinese study of a variant on 5p15.33 (rs2736100 near the TERT gene) and present a stronger association result for a moderately correlated variant (rs10069690; OR=1.20, P=3.2 × 10(-7)) based on our study of individuals of European ancestry. In combination, these results raise several opportunities for future studies of the pathogenes...
Genetic Testing and Molecular Biomarkers, Jan 4, 2013
TLR2 and TLR4 genetic variation has been investigated among the Saudis with the aim of gaining fu... more TLR2 and TLR4 genetic variation has been investigated among the Saudis with the aim of gaining further insight into the evolutionary history of the Arabian Peninsula. Two polymorphisms located in the TLR2 gene (Pro631His and Arg753Gln, rs5743704 and rs5743708, respectively), and two (Asp299Gly and Thr399Ile, rs4986790 and rs4986791, respectively), located in the TLR4 gene have been genotyped in 201 unrelated individuals from Saudi Arabia. While the G allele has been fixed in the Arg753Gln (g.2477 G&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;A) polymorphism, Pro631His (g.2111 C&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;A) show remarkable frequencies, a polymorphism that until now has been reported exclusively among European populations. The two TLR4 markers analyzed showed moderate frequencies (ranging from 4% to 5%). Considering the reported protective role of these polymorphisms against malaria, the data suggest that the regional variation at these gene loci could have been shaped by both evolutionary infection pressure and bidirectional human migrations in the past. The population admixture may be due to the existence of gene flow from Sub-Saharan Africa and the Levant to the Arabian Peninsula.
BACKGROUND: Dectin-1 is the major receptor for fungal beta-glucans on myeloid cells. We investiga... more BACKGROUND: Dectin-1 is the major receptor for fungal beta-glucans on myeloid cells. We investigated whether defective Dectin-1 receptor function, because of the early stop codon polymorphism Y238X, enhances susceptibility to invasive aspergillosis (IA) in at-risk patients. METHODS: Association of Dectin-1 Y238X polymorphism with occurrence and clinical course of IA was evaluated in 71 patients who developed IA post hematopoietic stem
ABSTRACT Background: Recurrent vulvo-vaginal candidiasis (RVVC) and other forms of mucocutanoeus ... more ABSTRACT Background: Recurrent vulvo-vaginal candidiasis (RVVC) and other forms of mucocutanoeus fungal infections are found in individuals without known immune defects. In contrast, disseminated fungal infections occur mostly in immunocompromised patients. We identified a family in which four members had various forms of mucocutanoeus fungal infections, and leukocytes with defective responses to beta-glucans in-vitro. Methods: Dectin-1 gen was sequenced and an early stop codon was identified in the CRD domain. The mutated dectin-1 was transfected in 3T3 cells and zymosan binding was performed. Cytokine production, phagocytosis and killing were assessed in monocytes and neutrophils. Results:We identified an early stop codon polymorphism in the the beta-glucan receptor dectin-1 as a cause of RVVC and onychomycosis in a family with four affected members. The mutated form of dectin-1 was not expressed on the surface of monocytes, macrophages and neutrophils of affected patients. When expressed in cell-lines, the mutated dectin-1 form did not mediate beta-glucan binding. Primary cells isolated from patients with dectin-1 mutations had defective cytokine production capacity after stimulation with beta-glucan or C. albicans (10 to 20% of controls). In contrast, phagocytosis and killing of Candida by primary macrophages and neutrophils was normal. Conclusions:the selective defect in cytokine production in patients defective for dectin-1 was the most likely cause of the mucosal fungal infections, while the normal phagocytosis and killing capacity of their neutrophils and macrophages explain why the dectin-1 deficiency was not associated with invasive fungal infections. These results highlight the specific role of dectin-1 in human mucosal antifungal defense.
Although non-medullary thyroid cancer (NMTC) generally has a good prognosis, 30-40% of patients w... more Although non-medullary thyroid cancer (NMTC) generally has a good prognosis, 30-40% of patients with distant metastases develop resistance to radioactive iodine (RAI) therapy due to tumor dedifferentiation. For these patients, treatment options are limited and prognosis is poor. In the present study, expression and activity of autophagy was assessed in large sets of normal, benign and malignant tissues and was correlated with pathology, SLC5A5/hNIS (solute carrier family 5 member 5) protein expression, and with clinical response to RAI ablation therapy in NMTC patients. Fluorescent immunostaining for the autophagy marker LC3 was performed on 100 benign and 80 malignant thyroid tissues. Semiquantitative scoring was generated for both diffuse LC3-I intensity and number of LC3-II-positive puncta and was correlated with SLC5A5 protein expression and clinical parameters. Degree of diffuse LC3-I intensity and number of LC3-IIpositive puncta scoring were not discriminative for benign vs. malignant thyroid lesions. Interestingly, however, in NMTC patients significant associations were observed between diffuse LC3-I intensity and LC3-II-positive puncta scoring on the one hand and clinical response to RAI therapy on the other hand (odds ratio [OR] D 3.13, 95% confidence interval [CI] D1.91-5.12, P D 0.01; OR D 5.68, 95%CI D 3.02-10.05, P D 0.002, respectively). Mechanistically, the number of LC3-II-positive puncta correlated with membranous SLC5A5 expression (OR D 7.71, 95%CI D 4.15-11.75, P<0.001), number of RAI treatments required to reach remission (P D 0.014), cumulative RAI dose (P D 0.026) and with overall remission and recurrence rates (P D 0.031). In conclusion, autophagy activity strongly correlates with clinical response of NMTC patients to RAI therapy, potentially by its capacity to maintain tumor cell differentiation and to preserve functional iodide uptake.
Alternative splicing is a biological mechanism that enables the synthesis of several isoforms wit... more Alternative splicing is a biological mechanism that enables the synthesis of several isoforms with different or even opposite functions. This process must be tightly regulated to prevent unwanted isoform expression favoring pathological processes. Some isoforms of interleukin 32 (IL-32) are reported to be more potent in inducing inflammation, however the role in cell death remains to be investigated. This study demonstrates that IL-32γ and IL-32β can induce caspase-8-dependent cell death whereas this was not observed for IL-32α. Overexpression of IL-32β or IL-32γ but not IL-32α, resulted in enhanced expression of the survival cytokine IL-8. Furthermore, restoring the IL-8 signaling pathway by overexpressing CXCR1 in HEK293 cells, rescued IL-32β- but not IL-32γ-induced cell death. Interestingly, IL-32γ was able to downregulate CXCR1 and thereby induce cell death. Subsequent studies into the role of IL-32 in thyroid cancer (TC) revealed that several IL-32 isoforms, IL-8, and CXCR1 are...
Up to 20%-30% of patients with metastatic non-medullary thyroid cancer have persistent or recurre... more Up to 20%-30% of patients with metastatic non-medullary thyroid cancer have persistent or recurrent disease resulting from tumor dedifferentiation. Tumor redifferentiation to restore sensitivity to radioactive iodide (RAI) therapy is considered a promising strategy to overcome RAI resistance. Autophagy has emerged as an important mechanism in cancer dedifferentiation. Here, we demonstrate the therapeutic potential of autophagy activators for redifferentiation of thyroid cancer cell lines. Five autophagy-activating compounds, all known as digitalis-like compounds, restored hNIS expression and iodide uptake in thyroid cancer cell lines. Upregulation of hNIS was mediated by intracellular Ca 2þ and FOS activation. Cell proliferation was inhibited by downregulating AKT1 and by induction of autophagy and p21-dependent cellcycle arrest. Digitalis-like compounds, also designated as cardiac glycosides for their well-characterized beneficial effects in the treatment of heart disease, could therefore represent a promising repositioned treatment modality for patients with RAI-refractory thyroid carcinoma. Mol Cancer Ther; 16(1); 169-81.
Differentiated thyroid cancer (DTC) is the most frequent endocrine tumor with a good prognosis af... more Differentiated thyroid cancer (DTC) is the most frequent endocrine tumor with a good prognosis after primary treatment in most cases. By contrast, 30–40% of patients with metastatic DTC are unresponsive to 131I radioactive iodide (RAI) treatment due to tumor dedifferentiation. Currently, underlying molecular mechanisms of dedifferentiation remain elusive and predictive biomarkers are lacking. Therefore, the present study aimed to identify molecular biomarkers in primary tumors associated with RAI refractoriness. A retrospective cohort was gathered consisting of RAI-sensitive patients with DTC and RAI-refractory patients with poorly DTC. In all patients, extensive intratumoral mutation profiling, gene fusions analysis, telomerase reverse transcriptase (TERT) promoter mutation analysis and formalin-fixed paraffin-embedded-compatible RNA sequencing were performed. Genetic analyses revealed an increased mutational load in RAI-refractory DTC, including mutations in AKT1, PTEN, TP53 and T...
4498 Dectin-1 is a C-type lectin receptor that recognizes b-1,3-glucan, and plays an important ro... more 4498 Dectin-1 is a C-type lectin receptor that recognizes b-1,3-glucan, and plays an important role in antifungal immunity. The recently discovered dectin-1 Y238X polymorphism, which results in “loss-of-function” has been shown associated with increased Candida colonization of stem cell transplantation (SCT) recipients. Besides its role in antifungal immunity Dectin-1 exhibits a broader function in immunity. Stimulation of Dectin-1 with β-glucan affects antigen presentation, modulates T-lymphocytic (CD4+, both Th1 and Th17, and CD8+) and B-lymphocytic responses, and induces cytokine production including interleukin (IL) 10, IL-12 and IL-23. These specific T-cell responses and cytokines are of particular interest in SCT because they are involved in graft-versus-leukemia (GvL) effects as well as in the pathogenesis of graft-versus-host disease (GvHD). Therefore we now performed a retrospective study in 140 patients on the impact of the Y238X polymorphism on the outcome of myeloablativ...
The intracellular proinflammatory mediator IL-32 is associated with tumor progression; however, t... more The intracellular proinflammatory mediator IL-32 is associated with tumor progression; however, the mechanisms remain unknown. We studied IL-32 mRNA expression as well as expression of other proinflammatory cytokines and mediators, including IL-1α, IL-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, the proangiogenic and antiapoptotic enzyme cyclooxygenase-2, the IL-8 receptor C-X-C chemokine receptor (CXCR) 1, and the intracellular kinase focal adhesion kinase-1. The interaction of IL-32 expression with expression of IL-6, TNF-α, IL-8, and cyclooxygenase-2 was also investigated. Biopsy specimens of 11 HIV-related, 7 non-HIV-related Kaposi sarcoma (KS), and 7 normal skin tissues (NSTs) of Dutch origin were analyzed. RNA was isolated from the paraffin material, and gene expression levels of IL-32 α, β, and γ isoforms, IL1a, IL1b, IL6, IL8, TNFA, PTGS2, CXCR1, and PTK2 were determined using real-time quantitative PCR. Significantly higher expression of IL-32β and IL-32γ isoforms was obs...
Objective: To analyze changes in fat cell size, macrophage infiltration, and local adipose tissue... more Objective: To analyze changes in fat cell size, macrophage infiltration, and local adipose tissue adipokine profiles in different fat depots in patients with active Cushing's syndrome. Methods: Subcutaneous (SC) and perirenal (PR) adipose tissue of 10 patients with Cushing's syndrome was compared to adipose tissue of 10 gender-, age-, and BMI-matched controls with regard to adipocyte size determined by digital image analysis on hematoxylin and eosin stainings, macrophage infiltration determined by digital image analysis on CD68 stainings, and adipose tissue leptin and adiponectin levels using fluorescent bead immunoassays and ELISA techniques. Results: Compared to the controls, mean adipocyte size was larger in PR adipose tissue in patients. The percentage of macrophage infiltration of the PR adipose tissue and PR adipose tissue lysate leptin levels were higher and adiponectin levels were lower in SC and PR adipose tissue lysates in patients. The adiponectin levels were also lower in the SC adipose tissue supernatants of patients. Associations were found between the severity of hypercortisolism and PR adipocyte size. Conclusions: Cushing's syndrome is associated with hypertrophy of PR adipocytes and a higher percentage of macrophage infiltration in PR adipose tissue. These changes are associated with an adverse local adipokine profile.
The NF-κB inflammatory pathway plays a major role in cancer development and clinical progression.... more The NF-κB inflammatory pathway plays a major role in cancer development and clinical progression. Activation of NF-κB signaling is promoted by NFKB1 and inhibited by NFKBIA. The present study aimed to determine the relevance of NFKB1 rs4648068 and NFKBIA rs2233406 genetic variants for non-medullary thyroid cancer (NMTC) susceptibility, progression and clinical outcome. This case–control and cohort study consists of a Romanian discovery cohort (157 patients and 258 controls) and a Dutch validation cohort (138 patients and 188 controls). In addition, patient cohorts were analyzed further for the association of genetic variants with clinical parameters. Functional studies were performed on human peripheral blood mononuclear cells. No associations were observed between the studied genetic variants and TC susceptibility. Although no statistically significant associations with clinical parameters were observed for NFKB1 rs4648068, the heterozygous genotype of NFKBIA rs2233406 was correlat...
The great majority of thyroid cancers are of the non-medullary type. Here we report findings from... more The great majority of thyroid cancers are of the non-medullary type. Here we report findings from a genome-wide association study of non-medullary thyroid cancer, including in total 3,001 patients and 287,550 controls from five study groups of European descent. Our results yield five novel loci (all with Pcombined<3 × 10(-8)): 1q42.2 (rs12129938 in PCNXL2), 3q26.2 (rs6793295 a missense mutation in LRCC34 near TERC), 5q22.1 (rs73227498 between NREP and EPB41L4A), 10q24.33 (rs7902587 near OBFC1), and two independently associated variants at 15q22.33 (rs2289261 and rs56062135; both in SMAD3). We also confirm recently published association results from a Chinese study of a variant on 5p15.33 (rs2736100 near the TERT gene) and present a stronger association result for a moderately correlated variant (rs10069690; OR=1.20, P=3.2 × 10(-7)) based on our study of individuals of European ancestry. In combination, these results raise several opportunities for future studies of the pathogenes...
Genetic Testing and Molecular Biomarkers, Jan 4, 2013
TLR2 and TLR4 genetic variation has been investigated among the Saudis with the aim of gaining fu... more TLR2 and TLR4 genetic variation has been investigated among the Saudis with the aim of gaining further insight into the evolutionary history of the Arabian Peninsula. Two polymorphisms located in the TLR2 gene (Pro631His and Arg753Gln, rs5743704 and rs5743708, respectively), and two (Asp299Gly and Thr399Ile, rs4986790 and rs4986791, respectively), located in the TLR4 gene have been genotyped in 201 unrelated individuals from Saudi Arabia. While the G allele has been fixed in the Arg753Gln (g.2477 G&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;A) polymorphism, Pro631His (g.2111 C&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;A) show remarkable frequencies, a polymorphism that until now has been reported exclusively among European populations. The two TLR4 markers analyzed showed moderate frequencies (ranging from 4% to 5%). Considering the reported protective role of these polymorphisms against malaria, the data suggest that the regional variation at these gene loci could have been shaped by both evolutionary infection pressure and bidirectional human migrations in the past. The population admixture may be due to the existence of gene flow from Sub-Saharan Africa and the Levant to the Arabian Peninsula.
BACKGROUND: Dectin-1 is the major receptor for fungal beta-glucans on myeloid cells. We investiga... more BACKGROUND: Dectin-1 is the major receptor for fungal beta-glucans on myeloid cells. We investigated whether defective Dectin-1 receptor function, because of the early stop codon polymorphism Y238X, enhances susceptibility to invasive aspergillosis (IA) in at-risk patients. METHODS: Association of Dectin-1 Y238X polymorphism with occurrence and clinical course of IA was evaluated in 71 patients who developed IA post hematopoietic stem
ABSTRACT Background: Recurrent vulvo-vaginal candidiasis (RVVC) and other forms of mucocutanoeus ... more ABSTRACT Background: Recurrent vulvo-vaginal candidiasis (RVVC) and other forms of mucocutanoeus fungal infections are found in individuals without known immune defects. In contrast, disseminated fungal infections occur mostly in immunocompromised patients. We identified a family in which four members had various forms of mucocutanoeus fungal infections, and leukocytes with defective responses to beta-glucans in-vitro. Methods: Dectin-1 gen was sequenced and an early stop codon was identified in the CRD domain. The mutated dectin-1 was transfected in 3T3 cells and zymosan binding was performed. Cytokine production, phagocytosis and killing were assessed in monocytes and neutrophils. Results:We identified an early stop codon polymorphism in the the beta-glucan receptor dectin-1 as a cause of RVVC and onychomycosis in a family with four affected members. The mutated form of dectin-1 was not expressed on the surface of monocytes, macrophages and neutrophils of affected patients. When expressed in cell-lines, the mutated dectin-1 form did not mediate beta-glucan binding. Primary cells isolated from patients with dectin-1 mutations had defective cytokine production capacity after stimulation with beta-glucan or C. albicans (10 to 20% of controls). In contrast, phagocytosis and killing of Candida by primary macrophages and neutrophils was normal. Conclusions:the selective defect in cytokine production in patients defective for dectin-1 was the most likely cause of the mucosal fungal infections, while the normal phagocytosis and killing capacity of their neutrophils and macrophages explain why the dectin-1 deficiency was not associated with invasive fungal infections. These results highlight the specific role of dectin-1 in human mucosal antifungal defense.
Although non-medullary thyroid cancer (NMTC) generally has a good prognosis, 30-40% of patients w... more Although non-medullary thyroid cancer (NMTC) generally has a good prognosis, 30-40% of patients with distant metastases develop resistance to radioactive iodine (RAI) therapy due to tumor dedifferentiation. For these patients, treatment options are limited and prognosis is poor. In the present study, expression and activity of autophagy was assessed in large sets of normal, benign and malignant tissues and was correlated with pathology, SLC5A5/hNIS (solute carrier family 5 member 5) protein expression, and with clinical response to RAI ablation therapy in NMTC patients. Fluorescent immunostaining for the autophagy marker LC3 was performed on 100 benign and 80 malignant thyroid tissues. Semiquantitative scoring was generated for both diffuse LC3-I intensity and number of LC3-II-positive puncta and was correlated with SLC5A5 protein expression and clinical parameters. Degree of diffuse LC3-I intensity and number of LC3-IIpositive puncta scoring were not discriminative for benign vs. malignant thyroid lesions. Interestingly, however, in NMTC patients significant associations were observed between diffuse LC3-I intensity and LC3-II-positive puncta scoring on the one hand and clinical response to RAI therapy on the other hand (odds ratio [OR] D 3.13, 95% confidence interval [CI] D1.91-5.12, P D 0.01; OR D 5.68, 95%CI D 3.02-10.05, P D 0.002, respectively). Mechanistically, the number of LC3-II-positive puncta correlated with membranous SLC5A5 expression (OR D 7.71, 95%CI D 4.15-11.75, P<0.001), number of RAI treatments required to reach remission (P D 0.014), cumulative RAI dose (P D 0.026) and with overall remission and recurrence rates (P D 0.031). In conclusion, autophagy activity strongly correlates with clinical response of NMTC patients to RAI therapy, potentially by its capacity to maintain tumor cell differentiation and to preserve functional iodide uptake.
Alternative splicing is a biological mechanism that enables the synthesis of several isoforms wit... more Alternative splicing is a biological mechanism that enables the synthesis of several isoforms with different or even opposite functions. This process must be tightly regulated to prevent unwanted isoform expression favoring pathological processes. Some isoforms of interleukin 32 (IL-32) are reported to be more potent in inducing inflammation, however the role in cell death remains to be investigated. This study demonstrates that IL-32γ and IL-32β can induce caspase-8-dependent cell death whereas this was not observed for IL-32α. Overexpression of IL-32β or IL-32γ but not IL-32α, resulted in enhanced expression of the survival cytokine IL-8. Furthermore, restoring the IL-8 signaling pathway by overexpressing CXCR1 in HEK293 cells, rescued IL-32β- but not IL-32γ-induced cell death. Interestingly, IL-32γ was able to downregulate CXCR1 and thereby induce cell death. Subsequent studies into the role of IL-32 in thyroid cancer (TC) revealed that several IL-32 isoforms, IL-8, and CXCR1 are...
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Papers by Theo Plantinga