Identification of IgG1 and IgG3 Allotypes by PCR and Sanger Sequencing.

The immunoglobulin heavy constant gamma (IGHG) gene cluster encoding immunoglobulin G (IgG) subclasses is highly polymorphic, resulting in amino acid variation along the antibody constant heavy chain referred to as allotypes. IGHG1 and IGHG3 are the two most polymorphic IgG subclasses in humans, with 4 classical IgG1 allotypes and 13 allotypes described for IgG3, though recent studies suggest greater allelic diversity, especially in underrepresented ethnic populations. Polymerase chain reaction (PCR) and Sanger sequencing of IGHG amplicons allow for the identification of the single nucleotide polymorphisms (SNPs) responsible for the observed amino acid substitutions. Here, we provide a detailed protocol for the amplification of IGHG1 and IGHG3 segments by PCR, sample preparation for Sanger sequencing, and analysis of sequencing data to identify SNPs associated with different IgG1 and IgG3 allotypes.

CXCL1/IGHG1 signaling enhances crosstalk between tumor cells and tumor-associated macrophages to promote MC-LR-induced colorectal cancer progression.

Microcystin-leucine arginine (MC-LR) is a common cyantotoxin produced by hazardous cyanobacterial blooms, and eutrophication is increasing the contamination level of MC-LR in drinking water supplies and aquatic foods. MC-LR has been linked to colorectal cancer (CRC) progression associated with tumor microenvironment, however, the underlying mechanism is not clearly understood. In present study, by using GEO, KEGG, GESA and ImmPort database, MC-LR related differentially expressed genes (DEGs) and pathway- and gene set-enrichment analysis were performed. Of the three identified DEGs (CXCL1, GUCA2A and GDF15), CXCL1 was shown a positive association with tumor infiltration, and was validated to have a dominantly higher upregulation in MC-LR-treated tumor-associated macrophages (TAMs) rather than in MC-LR-treated CRC cells. Both CRC cell/macrophage co-culture and xenograft mouse models indicated that MC-LR stimulated TAMs to secrete CXCL1 resulting in promoted proliferation, migration, and invasion capability of CRC cells. Furtherly, IP-MS assay found that interaction between TAMs-derived CXCL1 and CRC cell-derived IGHG1 may enhance CRC cell proliferation and migration after MC-LR treatment, and this effect can be attenuated by silencing IGHG1 in CRC cell. In addition, molecular docking analysis, co-immunoprecipitation and immunofluorescence further proved the interactions between CXCL1 and IGHG1. In conclusion, CXCL1 secreted by TAMs can trigger IGHG1 expression in CRC cells, which provides a new clue in elucidating the mechanism of MC-LR-mediated CRC progression.

Immunoglobulin heavy constant gamma 1 silencing decreases tonicity-responsive enhancer-binding protein expression to alleviate diabetic nephropathy.

AIMS/INTRODUCTION: The molecular mechanisms of diabetic nephropathy (DN) are poorly identified. However, the advantage of an increasing amount on microarray data of diabetic nephropathy intrigued us to explore the mechanisms based on bioinformatics prediction for diabetic nephropathy. MATERIALS AND METHODS: Bioinformatics analysis was conducted to screen the hub genes associated with diabetic nephropathy. The average human renal tubular epithelial cells were exposed to high glucose (HG) to generate an in vitro cell model. In addition, a mouse model of diabetic nephropathy was established using a high-fat diet and streptozotocin injection. Finally, the shRNA targeting immunoglobulin heavy constant gamma 1 (IGHG1) was introduced in vitro and in vivo to illustrate its effect on downstream factors and on the development diabetic nephropathy. RESULTS: Bioinformatics analysis revealed that IGHG1, TRIM11 (tripartite motif protein 11), and TonEBP are highly expressed in diabetic nephropathy. In vitro cell experiments demonstrated that IGHG1 positively regulates the expression of TRIM11 and TonEBP (tonicity-responsive enhancer binding protein) in HK2 cells treated with high glucose. Furthermore, TRIM11 upregulates the expression of TonEBP through activation of the MEK/ERK (mitogen-activated protein kinase/extracellular signal-regulated kinase) signaling pathway in HK2 cells treated with high glucose. In vivo, animal experiments further confirmed that silencing IGHG1 could prevent the occurrence and development of diabetic nephropathy. CONCLUSION: The silencing of IGHG1 alleviated diabetic nephropathy by inhibiting the TRIM11/MEK/ERK axis and by downregulating TonEBP.

Single-cell RNA sequencing reveals tumor immune microenvironment in human hypopharygeal squamous cell carcinoma and lymphatic metastasis.

Background: Human hypopharygeal squamous cell carcinoma (HSCC) is a common head and neck cancer with a poor prognosis in advanced stages. The occurrence and development of tumor is the result of mutual influence and co-evolution between tumor cells and tumor microenvironment (TME). Tumor immune microenvironment (TIME) refers to the immune microenvironment surrounding tumor cells. Studying TIME in HSCC could provide new targets and therapeutic strategies for HSCC. Methods: We performed single-cell RNA sequencing (scRNA-seq) and analysis of hypopharyngeal carcinoma, paracancerous, and lymphoid tissues from five HSCC patients. Subdivide of B cells, T cells, macrophages cells, and monocytes and their distribution in three kinds of tissues as well as marker genes were analyzed. Different genes of IGHG1 plasma cells and SPP1+ macrophages between HSCC tissues, adjacent normal tissues and lymphatic tissues were analyzed. Additionally, we studied proliferating lymphocytes, T cells exhaustion, and T cell receptor (TCR) repertoire in three kinds of tissues. Results: Transcriptome profiles of 132,869 single cells were obtained and grouped into seven cell clusters, including epithelial cells, lymphocytes, mononuclear phagocytics system (MPs), fibroblasts, endothelial cells (ECs), plasmacytoid dendritic cells (pDCs), and mast cells. Tumor metastasis occurred in three lymphoid tissues. Four distinct populations were identified from lymphocytes, including B cells, plasma cells, T cells and proliferating lymphocytes. We found IGHA1 and IGHG1 specific plasma cells significantly overexpressed in HSCC tissues compared with normal hypopharygeal tissues and lymphatic tissues. Five distinct populations from MPs were identified, including macrophages, monocytes, mature dendritic cells (DCs), Type 1 conventional dendritic cells (cDC1) and Type 2 conventional dendritic cells (cDC2). SPP1+ macrophages were significantly overexpressed in HSCC tissues and lymphatic tissues compared with normal hypopharygeal tissues, which are thought to be M2-type macrophages. Exhaustion of CD8+ Teff cells occurred in HSCC tissues. At last, we verified that IgA and IgG1 protein expression levels were significantly up-regulated in HSCC tissues compared to adjacent normal tissues. Conclusion: Overall, this study revealed TIME in HSCC and lymphatic metastasis, and provided potential therapeutic targets for HSCC.

Silencing of IGHG1 reverses the resistance of pancreatic cancer to multidrug chemotherapy by modulating autophagy.

BACKGROUND: Pancreatic cancer is one of the most aggressive tumors with a high-mortality rate. First-line drugs include 5-fluorouracil (5-FU), gemcitabine (GEM), and oxaliplatin (OXA). Resistance to 5-FU, GEM, and OXA is a major challenge. Immunoglobulin heavy chain F1 (IGHG1) participates in the regulation of cancer progression. It is still unclear how IGHG1 affects 5-FU, GEM, and OXA in pancreatic cancer. METHODS: The expression status of IGHG1 in pancreatic cancer was analyzed through bioinformatics tools. IGHG1 expression in pancreatic cancer tissues and cells was determined via RT-qPCR. Cell counting kit 8 assays, and flow cytometry analysis were utilized to detect the impact of IGHG1,5-FU, GEM, and OXA on cell proliferation and apoptosis. Western blotting was utilized to detect changes in the levels of the autophagy-associated proteins LC3, Beclin-1, p62, and ATG5. Immunofluorescence assays were employed to determine LC3 expression in cells. Xenograft experiments were conducted on nude mice to study tumor growth. RESULTS: IGHG1 was overexpressed in pancreatic cancer cells and tissues. IGHG1 expression was downregulated by 5-FU, GEM, or OXA treatment in cells. Treatment with 5-FU, GEM, or OXA repressed viability and promoted apoptosis and autophagy in pancreatic cancer cells. IGHG1 silencing exhibited the same results. Furthermore, IGHG1 depletion notably strengthened the effects of 5-FU, GEM, and OXA on pancreatic cancer cell viability, apoptosis, and autophagy. The combination of IGHG1 depletion with 5-FU, GEM, or OXA significantly reduced tumor growth in vivo. CONCLUSION: Silencing of IGHG1 could enhance 5-FU, GEM, or OXA function in pancreatic cancer and reverse resistance by regulating apoptosis and autophagy.

CSTF2T up-regulates IGHG1 by binding to ZEB1 to promote melanoma cell proliferation, migration, and invasion.

OBJECTIVES: Melanoma progression involves multiple molecular pathways. In this study, we explored the effect of immunoglobulin heavy constant gamma 1 (IGHG1) on melanoma progression. METHODS: IGHG1, zinc finger E-box binding homeobox 1 (ZEB1), and cleavage stimulation factor subunit 2 tau variant (CSTF2T) expression levels were measured by quantitative reverse-transcription polymerase chain reaction and western blot. BALB/c nude mice were subcutaneously injected with A375 cells to develop a transplantation tumor model, 4 weeks after which the tumor tissues were collected. Cell proliferation, cell invasion, and cell migration of A375 and SK-MEL-28 cells were measured after gain- and loss-of-function of IGHG1, ZEB1, and CSTF2T. Binding of ZEB1 to the IGHG1 promoter was assayed by chromatin immunoprecipitation and dual-luciferase reporter gene assays, while binding of CSTF2T to ZEB1 mRNA was investigated by RNA immunoprecipitation and RNA pull-down assays. RESULTS: IGHG1, ZEB1, and CSTF2T were all highly expressed in human melanoma cell lines. In A375 and SK-MEL-28 cells, ZEB1 binds directly to the IGHG1 promoter. ZEB1 silencing reduced IGHG1 expression and melanoma cell proliferative, invasive, and migratory properties, and these cellular effects were nullified by overexpression of IGHG1. CSTF2T binds directly to ZEB1 mRNA. Silencing of CSTF2T diminished ZEB1 expression and restrained melanoma cell proliferative, invasive, and migratory capabilities. The impacts of CSTF2T silencing on melanoma cells were counteracted by concomitant overexpression of ZEB1. CSTF2T knockdown reduced tumor volume and weight in nude mice. CONCLUSIONS: The CSTF2T-ZEB1-IGHG1 axis promotes melanoma cell proliferation and invasion.

High expression of IGHG1 promotes breast cancer malignant development by activating the AKT pathway.

This study researched the exact function of IgG1 heavy chain (IGHG1) on breast cancer (BC) progression. IGHG1 level within BC and paired normal tissues was acquired in Gene Expression Profiling Interactive Analysis dataset. Meanwhile, this work harvested tumor and paired healthy tissues in 42 BC cases. siRNA targeting IGHG1 was transfected into BC cells. SC79 was used to treat the transfected BC cells. CCK-8 assay, clone formation experiment, BrdU assay, Transwell experiment and flow cytometry were carried out to measure the viability, colony formation, proliferation, invasion, and apoptosis of BC cells. Paclitaxel and cisplatin sensitivity of BC cells was evaluated by MTT assay. Real-time quantitative reverse transcription-polymerase chain reaction and Western-blot were performed for measuring mRNA and protein expression. The overexpressed IGHG1 indicated dismal BC survival. IGHG1 silencing attenuated the viability, invasion, proliferation, epithelial-mesenchymal transition, but enhanced the apoptosis of BC cells. IGHG1 silencing enhanced the paclitaxel and cisplatin sensitivity of BC cells. IGHG1 silencing suppressed the activity of the MEK, AKT, and ERK pathways. AKT agonist partially reversed the inhibition of IGHG1 silencing on BC cell malignant phenotype and resistance to paclitaxel and cisplatin. IGHG1 promotes the malignant development of BC by activating the AKT pathway. It may be an effective target for BC treatment.

Immunoglobulin heavy constant gamma gene evolution is modulated by both the divergent and birth-and-death evolutionary models.

Immunoglobulin G (IgG) is one of the five antibody classes produced in mammals as part of the humoral responses accountable for protecting the organisms from infection. Its antibody heavy chain constant region is encoded by the Ig heavy-chain gamma gene (IGHG). In humans, there are four IGHG genes which encode the four subclasses, each with a specialized effector function. Although four subclasses of IgG proteins have also been reported in macaques, this does not appear to be the rule for all primates. In Platyrrhini, IgG has been stated to be encoded by a single-copy gene. To date, it remains unknown how the IGHG has expanded or contracted in the primate order; consequently, we have analyzed data from 38 primate genome sequences to identify IGHG genes and describe the evolution of IGHG genes in primate order. IGHG belongs to a multigene family that evolves by the birth-death evolutionary model in primates. Whereas Strepsirrhini and Platyrrhini have a single-copy gene, in Catarrhini, it has expanded to several paralogs in their genomes; some deleted and others pseudogenized. Furthermore, episodic positive selection may have promoted a species-specific IgG effector function. We propose that IgG evolved to reach an optimal number of copies per genome to adapt their humoral immune responses to different environmental conditions. This study has implications for biomedical trials using non-human primates.

IgG subclasses in New World Monkeys: an issue for debate?

Immunoglobulin G (IgG) is an essential antibody in adaptive immunity; a differential expansion of the gene encoding the Fc region (IGHG) of this antibody has been observed in mammals. Like humans, animal biomedical models, such as mice and macaques, have four functional genes encoding 4 IgG subclasses; however, the data for New World monkeys (NWM) seems contentious. Some publications argue for the existence of a single-copy gene for IgG Fc; however, a recent paper has suggested the presence of IgG subclasses in some NWM species. Here, we evaluated the genetic distances and phylogenetic relationships in NWM to assess the presence of IgG subclasses using the sequences of IGHG genes from 13 NWM species recovered from genomic data and lab PCR and cloning-based procedures available in GenBank. The results show that several sequences do not cluster into the expected taxon, probably due to cross-contamination during laboratory procedures, and consequently, they appear to be wrongly assigned. Additionally, several sequences reported as subclasses were shown to be 100% identical in the CH domains. The data presented here suggests that there is not enough evidence to establish the presence of IgG subclasses in NWM.

Association of Immunoglobulin G3 Hinge Region Length Polymorphism With Cerebral Malaria in Ghanaian Children.

Cerebral malaria (CM) may cause death or long-term neurological damage in children, and several host genetic risk factors have been reported. Malaria-specific immunoglobulin (Ig) G3 antibodies are crucial to human immune response against malaria. The hinge region of IgG3 exhibits length polymorphism (with long [L], medium [M], and short [S] alleles), which may influence its functionality. We studied IgG3 hinge region length polymorphisms in 136 Ghanaian children with malaria. Using logistic regression models, we found that children with the recessive MM allotype encoding medium IgG3 hinge region length had an increased risk of CM (adjusted odds ratio, 6.67 [95% confidence interval,1.30-34.32]; P=.004) . This has implications for future epidemiological studies on CM.

Upregulated Expression of Cancer-Derived Immunoglobulin G Is Associated With Progression in Glioma.

OBJECTIVE: Gliomas are the most aggressive intracranial tumors accounting for the vast majority of brain tumors with very poor prognosis and overall survival (OS). Cancer-derived immunoglobulin G (cancer-IgG) has been found to be widely expressed in several malignancies such as breast cancer, colorectal cancer, and lung cancer. Cancer-IgG could promote tumorigenesis and progression. However, its role in glioma has not been revealed yet. METHODS: We mined open databases including the Chinese Glioma Genome Atlas (CGGA), The Cancer Genome Atlas (TCGA), and the Gene Expression Omnibus (GEO) to study the role of IGHG1, which encodes cancer-IgG in glioma. Examination of the differential expression of IGHG1 was carried out in the GEO and TCGA databases. Furthermore, its expression in different molecular subtypes was analyzed. Stratified analysis was performed with clinical features. Subsequently, immune infiltration analysis was conducted using single-sample gene set enrichment analysis (ssGSEA). GSEA was performed to reveal the mechanisms of IGHG1. Lastly, immunohistochemistry was processed to validate our findings. RESULTS: In this study, we found that the expression of IGHG1 was higher in glioma and molecular subtypes with poor prognosis. The overall survival of patients with a high expression of IGHG1 was worse in the stratified analysis. Immune infiltration analysis indicated that the expression level of IGHG1 was positively correlated with the stromal score, ESTIMATE score, and immune score and negatively correlated with tumor purity. Results from the GSEA and DAVID demonstrated that IGHG1 may function in phagosome, antigen processing and presentation, extracellular matrix structural constituent, antigen binding, and collagen-containing extracellular matrix. Finally, immunohistochemistry assay validated our findings that patients with a high expression of cancer-IgG had poor OS and disease-free survival (DFS). CONCLUSION: Cancer-IgG is a promising biomarker of diagnosis and treatment for patients with glioma.

Down-regulation of IGHG1 enhances Protoporphyrin IX accumulation and inhibits hemin biosynthesis in colorectal cancer by suppressing the MEK-FECH axis.

Immunoglobulin γ-1 heavy chain constant region (IGHG1) is a functional isoform of immunoglobulins and plays an important role in the cytolytic activity of immune effector cells. Dysregulated IGHG1 was implicated in the occurrence and development of various tumors. Protoporphyrin IX (PpIX) is an endogenous fluorophore and is used in photodynamic therapy, which induces the generation of reactive oxygen species to initiate the death of tumor cells. However, the roles of IGHG1 in the colorectal cancer cell proliferation and PpIX accumulation have not been reported yet. Data from qRT-PCR and western blot analysis showed that IGHG1 was up-regulated in the colorectal cancer cells. Colorectal cancer cells were then transfected with shRNA targeting IGHG1 to down-regulate IGHG1 and conducted with Cell Counting Kit 8 (CCK8) and colony formation assays. Results demonstrated that shRNA-mediated down-regulation of IGHG1 decreased cell viability of colorectal cancer and suppressed cell proliferation. Moreover, PpIX accumulation was promoted and the hemin content was decreased by the silence of IGHG1. Interference of IGHG1 reduced the phosphorylated extracellular signal-regulated kinase (ERK) and ferrochelatase (FECH) expression, resulting in retarded cell proliferation in an MEK-FECH axis-dependent pathway.

Molecular characterisation of parvorder Platyrrhini IgG sub-classes.

Non-human primates (NHP) are essential in modern biomedical research; New World monkeys (NWM) are mainly used as an experimental model regarding human malaria as they provide useful information about the parasite's biology and an induced immune response. It is known that a vaccine candidate's efficacy is mediated by a protection-inducing antibody response (IgG). Not enough information is available concerning IgG subclasses' molecular characteristics regarding NHP from parvorder Platyrrhini. Understanding the nature of the humoral immune response and characterising the IgG subclasses' profile will provide valuable information about the immunomodulator mechanisms of vaccines evaluated using an NHP animal model. This article has characterised IgG subclasses in NWM (i.e. genera Aotus, Cebus, Ateles and Alouatta) based on the amplification, cloning and sequencing of the immunoglobulin heavy constant gamma (IGHG) gene's CH1 to CH3 regions. The resulting sequences enabled elucidating IGHG gene organisation; two IgG variants were found in the Aotus and Ateles monkey group and three IgG variants in the Cebus and Alouatta group. The sequences were highly conserved in Platyrrhini and had a similar structure to that reported for monkeys from parvorder Catarrhini. Such information will help in developing tools for a detailed characterisation of the humoral immune response in an NWM experimental animal model.

IGHG1 upregulation promoted gastric cancer malignancy via AKT/GSK-3ß/ß-Catenin pathway.

BACKGROUND: Despite current advances in gastric cancer treatment, disease metastasis and chemo-resistance remain as major hurdles against better overall prognosis. Previous studies indicated that IGHG1 as well as -Catenin serve as important regulators of tumor cellular malignancy. Therefore, understanding detailed molecular mechanism and identifying druggable target will be of great potentials in future therapeutic development. METHODS: Surgical tissues and gastric cancer cell lines were retrieved to evaluate IGHG1 expression for patients with or without lymph node/distal organ metastasis. Functional assays including CCK8 assay, Edu assay, sphere formation assay and transwell assay, wound healing assay, etc. were subsequently performed to evaluate the impact of IGHG1/-catenin axis on tumor cell proliferation, migration and chemo-resistance. RESULTS: Gastric cancer tissues and tumor cell lines demonstrated significantly higher level of IGHG1. Functional study further demonstrated that IGHG1 promoted proliferative and migration as well as chemo-resistance of gastric cancer tumor cells. Further experiments indicated that IGHG1 activated AKT/GSK-3/-Catenin axis, which played crucial role in regulation of proliferative and chemo-resistance of gastric cancer cells. CONCLUSION: This study provided novel evidences that IGHG1 acted as oncogene by promotion of gastric cancer cellular proliferation, migration and chemo-resistance. Our research further suggested that IGHG1/AKT/GSK-3ß/ß-Catenin axis acted as novel pathway which regulated gastric cancer cellular malignant behavior. Our research might inspire future therapy development to promote overall prognosis of gastric cancer patients.

IGHG1 induces EMT in gastric cancer cells by regulating TGF-ß/SMAD3 signaling pathway.

Objective: Gastric cancer is one of the most common malignant tumors in the world. IGHG1 is a differentially expressed protein screened out in gastric cancer in the early stage of the subject group. This topic explores the expression of IGHG1 in gastric cancer and the effect of IGHG1 on the proliferation, migration, invasion and EMT of gastric cancer SGC7901 cells and its mechanism of action. Methods: Twenty cases of gastric cancer were purified by laser Capture Microdissection. The isotopic tags for relative and absolute quantification was used to label the proteins, and then analyzed and identified them by quantitative proteomics. Immunohistochemical staining method was used to detect the expression of IGHG1 protein in gastric cancer tissues. Western blot was used to detect the expression of IGHG1 in gastric cancer cells. The MTT and Petri dish clone formation experiment analyzed the effect of low expression of IGHG1 on the proliferation of SGC7901 cells. Scratch test and Transwell migration and invasion test to observe the effect of low expression of IGHG1 on the migration and invasion of SGC7901 cells. Western blot was used to detect the effect of low expression of IGHG1 on the expression of EMT-related proteins. Results: 243 proteins related to gastric mucosal lesions were preliminarily identified. We found that IGHG1 is highly expressed in gastric cancer tissues compared with normal control tissues. IGHG1 promotes the proliferation, migration and invasion of gastric cancer cells. Compared with the control group, the expression of EMT-related proteins Vimentin, N-cadherin, TGF-ß, P-SMAD3 was decreased and the expression of E-cadherin was increased after IGHG1 low expression. Conclusions: IGHG1 induces EMT in SGC7901 cells by regulating the TGF-ß/SMAD3 signaling pathway.

Concerted variation of the 3' regulatory region of Ig heavy chain and Gm haplotypes across human continental populations.

OBJECTIVES: The 3' regulatory region of the immunoglobulin heavy chain gene (IGH) includes the HS1.2 enhancer displaying length polymorphism with four known variants. The goal of the research was to provide an overview of this variability and of its evolutionary significance across human populations. MATERIALS AND METHODS: We compiled published and original data on HS1.2 polymorphism in 3,100 subjects from 26 human populations. Moreover, we imputed the haplotypic arrangement of the HS1.2 region in the 1000 Genomes Project (1KGP). In this dataset, imputation could also be obtained for the G1m-G3m allotype by virtue of the precise correspondence between serological types and amino acid (and DNA) substitutions in IGHG1 and IGHG3. RESULTS: HS1.2 variant frequencies displayed similar patterns of continental partitioning as those reported in the literature for the physically neighboring IGHG1-IGHG3 system. The 1KGP data revealed that linkage disequilibrium (LD) can explain the spread of joint HS1.2-IGHG1-IGHG3 associations across continents and within continental populations, with stronger LD out of Africa and the features of an evolutionarily stable genomic block with differential expression in lymphoblastoid cell lines. DISCUSSION: Strong population structuring involves at least the entire 70 kb genomic region here considered, due to the tight LD which maintained HS1.2, IGHG1, and IGHG3 in nonrandom arrangements. This might be key to better understand the evolutionary path of the entire genomic region driven by immune response capabilities, during the formation of continental gene pools.

Cardiac Disease in Childhood Cancer Survivors: Risk Prediction, Prevention, and Surveillance: JACC CardioOncology State-of-the-Art Review.

Cardiac diseases in the growing population of childhood cancer survivors are of major concern. Cardiotoxicity as a consequence of anthracyclines and chest radiotherapy continues to be relevant in the modern treatment era. Mitoxantrone has emerged as an important treatment-related risk factor and evidence on traditional cardiovascular risk factors in childhood cancer survivors is accumulating. International surveillance guidelines have been developed with the aim to detect and manage cardiac diseases early and prevent symptomatic disease. There is growing interest in risk prediction models to individualize prevention and surveillance. This State-of-the-Art Review summarizes literature from a systematic PubMed search focused on cardiac diseases after treatment for childhood cancer. Here, we discuss the prevalence, risk factors, prevention, risk prediction, and surveillance of cardiac diseases in survivors of childhood cancer.

Unveiling the Diversity of Immunoglobulin Heavy Constant Gamma (IGHG) Gene Segments in Brazilian Populations Reveals 28 Novel Alleles and Evidence of Gene Conversion and Natural Selection.

Even though immunoglobulins are critical for immune responses and human survival, the diversity of the immunoglobulin heavy chain gene (IGH) is poorly known and mostly characterized only by serological methods. Moreover, this genomic region is not well-covered in genomic databases and genome-wide association studies due to particularities that impose technical difficulties for its analysis. Therefore, the IGH gene has never been systematically sequenced across populations. Here, we deliver an unprecedented and comprehensive characterization of the diversity of the IGHG1, IGHG2, and IGHG3 gene segments, which encode the constant region of the most abundant circulating immunoglobulins: IgG1, IgG2, and IgG3, respectively. We used Sanger sequencing to analyze 357 individuals from seven different Brazilian populations, including five Amerindian, one Japanese-descendant and one Euro-descendant population samples. We discovered 28 novel IGHG alleles and provided evidence that some of them may have been originated by gene conversion between common alleles of different gene segments. The rate of synonymous substitutions was significantly higher than the rate of the non-synonymous substitutions for IGHG1 and IGHG2 (p = 0.01 and 0.03, respectively), consistent with purifying selection. Fay and Wu's test showed significant negative values for most populations (p < 0.001), which indicates that positive selection in an adjacent position may be shaping IGHG variation by hitchhiking of variants in the vicinity, possibly the regions that encode the Ig variable regions. This study shows that the variation in the IGH gene is largely underestimated. Therefore, exploring its nucleotide diversity in populations may provide valuable information for comprehension of its evolution, its impact on diseases and vaccine research.

IGHG1 promotes motility likely through epithelial-mesenchymal transition in ovarian cancer.

OBJECTIVE: Ovarian cancer (OC) is one of the leading causes of death for female cancer patients. COC166-9 is an OC-specific monoclonal antibody and we have identified immunoglobulin γ-1 heavy chain constant region (IGHG1) as its antigen. We explore the function of IGHG1 in proliferation, apoptosis and motility of OC cells further in this research. METHODS: IGHG1 expression in OC specimens was detected through immunohistochemistry. Real-time quantitative polymerase chain reaction (RT-qPCR) or western blotting assay was used to test IGHG1 expression in OC cells. Viability of OC cells was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry or western blotting assay was used to detect cell cycle and apoptosis. Cellular motility was analyzed by using transwell assay and the markers of epithelial-mesenchymal transition (EMT) were tested through immunoblots. RESULTS: Although it exerts negligible effect on the viability and apoptosis of OC cells, IGHG1 could promote migration and invasion of malignant cells in vitro. Mechanistically, IGHG1 increases the expression of N-cadherin and Vimentin while decreases E-cadherin expression. Additionally, IGHG1 expression in OC specimens is higher relative to the paired normal counterparts. Further analysis demonstrates that the increased IGHG1 expression correlates positively with the lymph node metastasis of OC. CONCLUSIONS: IGHG1 promotes the motility of OC cells likely through executing the EMT program. Increased IGHG1 expression in OC specimens is associated with the lymph node metastasis.

Leporid immunoglobulin G shows evidence of strong selective pressure on the hinge and CH3 domains.

Immunoglobulin G (IgG) is the predominant serum immunoglobulin and has the longest serum half-life of all the antibody classes. The European rabbit IgG has been of significant importance in immunological research, and is therefore well characterized. However, the IgG of other leporids has been disregarded. To evaluate the evolution of this gene in leporids, we sequenced the complete IGHG for six other genera: Bunolagus, Brachylagus, Lepus, Pentalagus, Romerolagus and Sylvilagus. The newly sequenced leporid IGHG gene has an organization and structure similar to that of the European rabbit IgG. A gradient in leporid IgG constant domain diversity was observed, with the CH1 being the most conserved and the CH3 the most variable domain. Positive selection was found to be acting on all constant domains, but with a greater incidence in the CH3 domain, where a cluster of three positively selected sites was identified. In the hinge region, only three polymorphic positions were observed. The same hinge length was observed for all leporids. Unlike the variation observed for the European rabbit, all 11 Lepus species studied share exactly the same hinge motif, suggesting its maintenance as a result of an advantageous structure or conformation.