Characterization of β2-microglobulin expression in different types of breast cancer

Adaptive digital tissue deconvolution

MOTIVATION

The inference of cellular compositions from bulk and spatial transcriptomics data increasingly complements data analyses. Multiple computational approaches were suggested and recently, machine learning techniques were developed to systematically improve estimates. Such approaches allow to infer additional, less abundant cell types. However, they rely on training data which do not capture the full biological diversity encountered in transcriptomics analyses; data can contain cellular contributions not seen in the training data and as such, analyses can be biased or blurred. Thus, computational approaches have to deal with unknown, hidden contributions. Moreover, most methods are based on cellular archetypes which serve as a reference; e.g. a generic T-cell profile is used to infer the proportion of T-cells. It is well known that cells adapt their molecular phenotype to the environment and that pre-specified cell archetypes can distort the inference of cellular compositions.

RESULTS

We propose Adaptive Digital Tissue Deconvolution (ADTD) to estimate cellular proportions of pre-selected cell types together with possibly unknown and hidden background contributions. Moreover, ADTD adapts prototypic reference profiles to the molecular environment of the cells, which further resolves cell-type specific gene regulation from bulk transcriptomics data. We verify this in simulation studies and demonstrate that ADTD improves existing approaches in estimating cellular compositions. In an application to bulk transcriptomics data from breast cancer patients, we demonstrate that ADTD provides insights into cell-type specific molecular differences between breast cancer subtypes.

AVAILABILITY AND IMPLEMENTATION

A python implementation of ADTD and a tutorial are available at Gitlab and zenodo (doi:10.5281/zenodo.7548362).

Beta2-Microglobulin as Predictive Biomarkers in the Prognosis of Hepatocellular Carcinoma and Development of a New Nomogram

Background

Accurate prognosis is crucial for improving hepatocellular carcinoma (HCC) patients, clinical management, and outcomes post-liver resection. However, the lack of reliable prognostic indicators poses a significant challenge. This study aimed to develop a user-friendly nomogram to predict HCC patients' post-resection prognosis.

Methods

We retrospectively analyzed the data from 1091 HCC patients, randomly split into training (n=767) and validation (n=324) cohorts. Receiver operating characteristic (ROC) curves determined the optimal cut-off value for alpha1-microglobulin (α1MG) and Beta2-microglobulin (β2MG). Kaplan-Meier analysis assessed microglobulin's impact on survival, followed by Cox regression to identify prognostic factors and construct a nomogram. The predictive accuracy and discriminative ability of the nomogram were measured by the concordance index (C-index), calibration curves, area under the ROC curve (AUC), and decision curve analysis (DCA), and were compared with the BCLC staging system, Edmondson grade, or BCLC stage plus Edmondson grade.

Results

Patients with high β2MG (≥2.395mg/L) had worse overall survival (OS). The nomogram integrated β2MG, BCLC stage, Edmondson grade, microvascular invasion (MVI), and serum carbohydrate antigen 199 (CA199) levels. C-index for training and validation cohorts (0.712 and 0.709) outperformed the BCLC stage (0.660 and 0.657), Edmondson grade (0.579 and 0.564), and the combination of BCLC stage with Edmondson grade (0.681 and 0.668), improving prognosis prediction. Calibration curves demonstrated good agreement between predicted and observed survival. AUC values exceeded 0.700 over time, highlighting the nomogram's discriminative ability. DCA revealed superior overall net income compared to other systems, emphasizing its clinical utility.

Conclusion

Our β2MG-based nomogram accurately predicts HCC patients' post-resection prognosis, aiding intervention and follow-up planning. Significantly, our nomogram surpasses existing prognostic indicators, including BCLC stage, Edmondson grade, and the combination of BCLC stage with Edmondson grade, by demonstrating superior predictive performance.

Hormone Receptor Signaling and Breast Cancer Resistance to Anti-Tumor Immunity

Breast cancers regroup many heterogeneous diseases unevenly responding to currently available therapies. Approximately 70-80% of breast cancers express hormone (estrogen or progesterone) receptors. Patients with these hormone-dependent breast malignancies benefit from therapies targeting endocrine pathways. Nevertheless, metastatic disease remains a major challenge despite available treatments, and relapses frequently ensue. By improving patient survival and quality of life, cancer immunotherapies have sparked considerable enthusiasm and hope in the last decade but have led to only limited success in breast cancers. In addition, only patients with hormone-independent breast cancers seem to benefit from these immune-based approaches. The present review examines and discusses the current literature related to the role of hormone receptor signaling (specifically, an estrogen receptor) and the impact of its modulation on the sensitivity of breast cancer cells to the effector mechanisms of anti-tumor immune responses and on the capability of breast cancers to escape from protective anti-cancer immunity. Future research prospects related to the possibility of promoting the efficacy of immune-based interventions using hormone therapy agents are considered.

Analysis of the B2M Expression in Colon Adenocarcinoma and Its Correlation with Patient Prognosis

Colon adenocarcinoma (COAD) is one of the most common malignant tumors in clinics. It is often found at an advanced stage, with high incidence and poor prognosis; early diagnosis is difficult and treatment methods are limited. In order to find new methods for diagnosis and treatment of COAD, people pay more and more attention to the discovery and functional research of new oncogenes and tumor suppressor genes of COAD. β2-microglobulin (B2M) plays different physiological and pathological roles in tumor cells and nontumor cells. At present, there is no public report on the expression of B2M in COAD. In this study, the expression of B2M mRNA in COAD tissues was compared with that in normal tissues. The relationship between the expression of B2M mRNA and the stage, histological subtype, lymph node metastasis, TP53 mutation, and survival time of COAD was discussed. It was found that B2M is a potential tumor suppressor gene in COAD. The decreased expression of B2M after mutation can cause immune escape of COAD cells, thus affecting the therapeutic effect and prognosis. This study provides a new idea for the prevention and treatment of COAD.

Estrogen distinctly regulates transcription and translation of lncRNAs and pseudogenes in breast cancer cells

Estrogen drives key transcriptional changes in breast cancer and stimulates breast cancer cells' growth with multiple mechanisms to coordinate transcription and translation. In addition to protein-coding transcripts, estrogen can regulate long non-coding RNA (lncRNA) transcripts, plus diverse non-coding RNAs including antisense, enhancer, and intergenic. LncRNA genes comprise the majority of human genes. The accidental, or regulated, translation of their short open reading frames by ribosomes remains a controversial topic. Here we report for the first time an integrated analysis of RNA abundance and ribosome occupancy level, using Ribo-seq combined with RNA-Seq, in the estrogen-responsive, estrogen receptor α positive, human breast cancer cell model MCF7, before and after hormone treatment. Translational profiling can determine, in an unbiased manner, which fraction of the genome is actually translated into proteins, as well as resolving whether transcription and translation respond concurrently, or differentially, to estrogen treatment. Our data showed specific transcripts more robustly detected in RNA-Seq than in the ribosome-profiling data, and vice versa, suggesting distinct gene-specific estrogen responses at the transcriptional and the translational level, respectively. Here, we showed that estrogen stimulation affects the expression levels of numerous lncRNAs, but not their association with ribosomes, and that most lncRNAs are not ribosome-bound. For the first time, we also demonstrated the transcriptional and translational response of expressed pseudogenes to estrogen, pointing to new perspectives for drug-target development in breast cancer in the future.

Aberrant RET expression impacts on normal mammary gland post-lactation transition enhancing cancer potential

RET is a receptor tyrosine kinase with oncogenic potential in the mammary epithelium. Several receptors with oncogenic activity in the breast are known to participate in specific developmental stages. We found that RET is differentially expressed during mouse mammary gland development: RET is present in lactation and its expression dramatically decreases in involution, the period during which the lactating gland returns to a quiescent state after weaning. Based on epidemiological and pre-clinical findings, involution has been described as tumor promoting. Using the Ret/MTB doxycycline-inducible mouse transgenic system, we show that sustained expression of RET in the mammary epithelium during the post-lactation transition to involution is accompanied by alterations in tissue remodeling and an enhancement of cancer potential. Following constitutive Ret expression, we observed a significant increase in neoplastic lesions in the post-involuting versus the virgin mammary gland. Furthermore, we show that abnormal RET overexpression during lactation promotes factors that prime involution, including premature activation of Stat3 signaling and, using RNA sequencing, an acute-phase inflammatory signature. Our results demonstrate that RET overexpression negatively affects the normal post-lactation transition.

Summary: We show that RET activation stimulates Stat3 signaling in mammary epithelial cell culture and in vivo during post-lactation transition, demonstrating that the RET receptor participates in the post-lactation transition priming tumorigenesis.

Serum β-2 microglobulin levels are associated with distant metastasis in patients with breast cancer

Serum β-2 microglobulin (β2-M) levels have been identified to be higher in patients with cancer than in healthy individuals. The aim of the present study was to evaluate the association between serum β2-M levels and clinicopathological characteristics of patients with breast cancer in a prospective cohort study, and to evaluate the effect of β2-M on cancer cell migration in vitro. Serum samples from 200 female patients with histologically confirmed invasive breast cancer were collected between 2017 and 2019. Their clinicopathological information was obtained and analyzed. The β2-M levels were identified to be associated with age, histologic subtype and metastatic status. When the diagnostic association of β2-M and metastatic status was analyzed, the area under the receiver operating characteristic curve was 0.78. Using a cut-off serum β2-M level of 1.9 µg/ml, the sensitivity for diagnosing metastatic status was 87.5%, the specificity was 65.0%, and the diagnostic odds ratio was 2.47. Upon age stratification, the association between the β2-M level and metastatic status was significant only in the group aged >55 years. In survival analysis, β2-M levels >1.9 µg/ml were associated with a poor survival outcome. In vitro, the MCF-7 breast cancer cell line exhibited increased cellular migration following treatment with 30 µg/ml β2-M. Serum β2-M may be a predictor of metastatic status in breast cancer.

Cancer Immune Evasion Through Loss of MHC Class I Antigen Presentation

Major histocompatibility class I (MHC I) molecules bind peptides derived from a cell's expressed genes and then transport and display this antigenic information on the cell surface. This allows CD8 T cells to identify pathological cells that are synthesizing abnormal proteins, such as cancers that are expressing mutated proteins. In order for many cancers to arise and progress, they need to evolve mechanisms to avoid elimination by CD8 T cells. MHC I molecules are not essential for cell survival and therefore one mechanism by which cancers can evade immune control is by losing MHC I antigen presentation machinery (APM). Not only will this impair the ability of natural immune responses to control cancers, but also frustrate immunotherapies that work by re-invigorating anti-tumor CD8 T cells, such as checkpoint blockade. Here we review the evidence that loss of MHC I antigen presentation is a frequent occurrence in many cancers. We discuss new insights into some common underlying mechanisms through which some cancers inactivate the MHC I pathway and consider some possible strategies to overcome this limitation in ways that could restore immune control of tumors and improve immunotherapy.

Salivary β2-microglobulin levels in patients with erosive oral lichen planus and squamous cell carcinoma

OBJECTIVES

β2 microglobulin, as a biomarker, is used for the diagnosis of oral malignant and pre-malignant lesions. The components of the microglobulin system can directly or indirectly help grow and develop tumors. The present study aims to compare beta-2 microglobulin levels in patients with lichen planus of the esophagus, oral squamous cell carcinoma, and healthy individuals. Further, it evaluated the salivary β2-microglobulin level in malignant and pre-malignant lesions. Oral lichen planus (OLP) is a chronic skin-mucus disorder. Of the total 75 patients referred to Oral Medicine at Dentistry School of Zahedan University of Medical Sciences, 25 were healthy and 25 had oral lichen planus (OLP) and the rest had squamous cell carcinoma (SCC). To collect the saliva samples, unstimulated spitting was used. They were collected between 9 and 12 a.m. Salivary beta2 microglobulin was recorded based on the factory instructions by ELISA optical density method with 450 nm wavelength for each sample. The data were analyzed using descriptive, Kruskal-Wallis and Mann-Whitney and Pearson's correlation coefficient (SPSS 21).

RESULTS

The salivary β2 microglobulin level in patients with squamous cell carcinoma (SCC) and oral lichen plan (OLP) is significantly higher than that in healthy group. Thus, this index is used for assessing early malignant transformation and oral pre-malignant lesion.

Downregulation of beta-catenin in chemo-tolerant TNBC through changes in receptor and antagonist profiles of the WNT pathway: Clinical and prognostic implications

PURPOSE

In approximately 30% of triple-negative breast cancer (TNBC) patients a complete pathological response is achieved. However, after neo-adjuvant chemotherapy treatment (NACT) residual tumour cells can be intrinsically resistant to chemotherapy. In this study, associations of the WNT/beta-catenin pathway with chemo-tolerance of NACT treated TNBC patients were compared to that of pre-treatment TNBC patients.

METHODS

Expression analyses were performed in both pre-treatment and NACT treated TNBC samples using immunohistochemistry and qRT-PCR, along with DNA copy number variation (CNV) and promoter methylation analyses to elucidate the mechanism(s) underlying chemo-tolerance. In addition, in vitro validation experiments were performed in TNBC cells followed by in vivo clinicopathological correlation analyses.

RESULTS

A reduced expression (41.1%) of nuclear beta-catenin together with a low proliferation index was observed in NACT samples, whereas a high expression (59.0%) was observed in pre-treatment samples. The reduced nuclear expression of beta-catenin in the NACT samples showed concordance with reduced expression levels (47-52.9%) of its associated receptors (FZD7 and LRP6) and increased expression levels (35.2-41.1%) of its antagonists (SFRP1, SFRP2, DKK1) compared to those in the pre-treatment samples. The expression levels of the receptors showed no concordance with its respective gene copy number/mRNA expression statuses, regardless treatment. Interestingly, however, significant increases in promoter hypomethylation of the antagonists were observed in the NACT samples compared to the pre-treatment samples. Similar expression patterns of the antagonists, receptors and beta-catenin were observed in the TNBC-derived cell line MDA-MB-231 using the anthracyclines doxorubicin and nogalamycin, suggesting the importance of promoter hypomethylation in chemotolerance. NACT patients showing reduced receptor and/or beta-catenin expression levels and high antagonist expression levels exhibited a comparatively better prognosis than the pre-treatment patients.

CONCLUSIONS

Our data suggest that reduced nuclear expression of beta-catenin in NACT TNBC samples, due to downregulation of its receptors and upregulation of its antagonists through promoter hypomethylation of the WNT pathway, plays an important role in chemo-tolerance.

Primary Gastric Diffuse Large B-Cell Lymphoma: Prognostic Factors in the Immuno-Oncology Therapeutics Era

Objective:

This study aimed to explore the prognostic factors for primary gastric diffuse large B-cell lymphoma (PG-DLBCL).

Materials and Methods:

This retrospective study analyzed 72 PG-DLBCL patients between January 2012 and December 2017 in the Shanxi Cancer Hospital of Shanxi Medical University to identify the different prognostic factors in PG-DLBCL. The clinical features, treatment, and follow-up information were analyzed.

Results:

The low CD4:CD8 ratio group (median subsequent overall survival [OS]: 36.06 months; 95% confidence interval [CI]: 25.73-46.40) showed a significant decrease in subsequent OS compared to the normal group among PG-DLBCL patients who were newly diagnosed and did not receive rituximab (median OS: 52.58 months; 95% CI: 44.18-60.97; p=0.029). Event-free survival status 24 months after the date of diagnosis (EFS24) also decreased significantly in the low CD4:CD8 group (median EFS24: 16.27 months; 95% CI: 13.09-19.45) compared to the normal group (median EFS24: 20.34 months; 95% CI: 17.05-23.63; p=0.014). Multivariate analysis showed that low CD4:CD8 at diagnosis was an independent poor prognostic factor for subsequent OS and EFS24.

Conclusion:

Our data suggest that identifying prognostic factors, especially host immunity, may provide useful information for assessing prognosis or clinical management.

A prognostic nomogram constructed for relapsed or refractory diffuse large B-cell lymphoma patients

AIM

The clinical course of diffuse large B-cell lymphoma (DLBCL) is variable and there is a lack of prognostic markers and models for relapsed or refractory (r/r) DLBCL. Hence, we conducted this study to identify independent factors that can predict the survival rate of r/r DLBCL patients.

METHODS

A total of 416 r/r DLBCL patients who were pretreated with first-line anthracycline-based chemotherapy at the National Cancer Center in China between 2006 and 2016 were divided into the primary (n = 291) and validation (n = 125) cohorts. The effect of preclinical and clinical indicators on DLBCL survival rates of the two cohorts were evaluated by univariate and multivariate analyses. Factors showing good correlation with patient survival rates were used to construct a prognostic nomogram.

RESULTS

Multivariate analysis of the primary cohort revealed five independent prognostic factors: lactate dehydrogenase level at diagnosis, response to front line treatment, progression/recurrence pattern, location, and invasion on progression/recurrence, which were then used to construct a nomogram. The nomogram was shown to have a C-index of 0.76 and AUC values of 0.81 and 0.80 for the primary and validation cohorts, respectively, suggesting good prognostic power. We further stratified the r/r DLBCL patients into four risk groups according to the newly developed nomogram.

CONCLUSION

The prognostic nomogram constructed using the five identified clinical indicators can potentially be applied in the clinical setting to guide treatment decision.

β2-microglobulin has a different regulatory molecular mechanism between ER+ and ER- breast cancer with HER2. BMC Cancer 2019;19:223. [PMID: 30866857 PMCID: PMC6417228 DOI: 10.1186/s12885-019-5410-1]

Background

Previous studies have demonstrated that β2-microglobulin (β2M) promotes the growth and survival of a variety of cancer cells and has different regulatory effects on the expression of Bcl-2 and HER2 in HER2⁻ breast cancer cells. However, β2M-mediated signaling in ER⁺ and ER⁻ breast cancer with HER2⁻ remains unclear.

Methods

β2M expression vector and siRNA were transfected into two types of HER2⁻ breast cancer cells, and the possible relevant signaling molecules were subsequently analyzed by real-time PCR and western blotting. These signaling molecules were also analyzed by real-time PCR and immunohistochemistry (IHC) in two types of HER2⁻ breast cancer tissues, and the associations between β2M and these signaling molecules were assessed using Spearman’s correlation analysis.

Results

β2M silencing downregulated p-SGK1/SGK1 levels and Bcl-2 expression, and β2M overexpression downregulated p-CREB/CREB and significantly upregulated p-SGK1/SGK1 levels and Bcl-2 expression, and both resulting processes did not affect HER2, HIF-1α, VEGF, and ERK signaling in ER⁺ breast cancer cells with HER2⁻. β2M silencing upregulated p-CREB/CREB and VEGF protein and significantly downregulated p-ERK/ERK levels, and β2M overexpression downregulated p-CREB/CREB and VEGF, significantly upregulated p-ERK/ERK levels, and both resulting processes did not affect HIF-1α and SGK1 signaling in ER⁻ breast cancer cells with HER2⁻. β2M expression was positively correlated with p-CREB, p-SGK1, and Bcl-2 expression and had no correlation with HIF-1α, VEGF, and p-ERK1/2, whereas p-SGK1 exhibited a significantly positive correlation with Bcl-2 expression in cancer tissues of patients with luminal A breast cancer, which coincide with the results obtained from the same molecular types of breast cancer cells except CREB signaling. However, β2M expression did not show a significant correlation with HIF-1α, p-CREB, VEGF, p-SGK1, p-ERK1/2, and Bcl-2 expression in cancer tissues of patients with basal-like breast cancer, which was discordant with the results obtained from the same molecular types of breast cancer cells.

Conclusions

β2M has a different molecular regulatory mechanism between ER⁺ and ER⁻ breast cancer with HER2⁻, and it may promote tumor survival through the SGK1/Bcl-2 signaling pathway in ER⁺ breast cancer with HER2⁻ and has no regulatory effects on ER⁻ breast cancer with HER2⁻.

Beta 2-microglobulin regulates amyloid precursor-like protein 2 expression and the migration of pancreatic cancer cells

Beta 2-microglobulin (β₂m) is a component of the major histocompatibility complex (MHC) class I molecule, which presents tumor antigens to T lymphocytes to trigger cancer cell destruction. Notably, β₂m has been reported as persistently expressed, rather than down regulated, in some tumor types. For renal cell and oral squamous cell carcinomas, β₂m expression has been linked to increased migratory capabilities. The migratory ability of pancreatic cancer cells contributes to their metastatic tendencies and lethal nature. Therefore, in this study, we examined the impact of β₂m on pancreatic cancer cell migration. We found that β₂m protein is amply expressed in several human pancreatic cancer cell lines (S2-013, PANC-1, and MIA PaCa-2). Reducing β₂m expression by short interfering RNA (siRNA) transfection significantly slowed the migration of the PANC-1 and S2-013 cancer cell lines, but increased the migration of the MIA PaCa-2 cell line. The amyloid precursor-like protein 2 (APLP2) has been documented as contributing to pancreatic cancer cell migration, invasiveness, and metastasis. We have previously shown that β₂m/HLA class I/peptide complexes associate with APLP2 in S2-013 cells, and in this study we also detected their association in PANC-1 cells but not MIA PaCa-2 cells. In addition, siRNA down regulation of β₂m expression diminished the expression of APLP2 in S2-013 and PANC-1 but heightened the level of APLP2 in MIA PaCa-2 cells, consistent with our migration data and co-immunoprecipitation data. Thus, our findings indicate that β₂m regulates pancreatic cancer cell migration, and furthermore suggest that APLP2 is an intermediary in this process.

Novel prognostic scoring system for diffuse large B-cell lymphoma

The objective of the present study was to evaluate the prognostic values of platelet count (PLT) and platelet to lymphocyte ratio (PLR) in diffuse large B-cell lymphoma (DLBCL), creating a novel prognostic scoring system. A total of 309 patients with newly diagnosed DLBCL were retrospectively analyzed. Receiver operating characteristic analysis was used to determine the optimal threshold values for PLT and PLR, which were 250×10⁹/l and 170, respectively. The patients with PLT ≥250×10⁹/l and PLR ≥170 experienced significantly decreased overall survival (OS) (P<0.001) and progression-free survival (PFS) times (P=0.003, P<0.001) In multivariate analysis, PLR was a significant prognostic factor for OS (P<0.001) and PFS (P=0.003) time, whereas PLT was not a risk factor for PFS or OS time. According to the results of Cox regression analysis, a novel prognostic scoring system was created that combined PLR and β2-microglobulin level with International Prognostic Index value or age-adjusted International Prognostic Index value and the patients were divided into three groups: i) Low-risk patients with a PLR <170, International Prognostic Index (IPI) <2 scores or age-adjusted International Prognostic Index (aaIPI)=0 and normal β2m; ii) high-risk patients with a PLR ≥170, IPI ≥4 or aaIPI=3 and high level of β2m; and iii) intermediate-risk patients. The novel score predicted 5-year OS rates of 86.4, 54.1 and 21.1% in the low-, intermediate- and high-risk groups, respectively (P<0.001). This novel prognostic scoring system may aid the evaluation of patient prognosis and guide treatment.

A strategy to identify housekeeping genes suitable for analysis in breast cancer diseases

BACKGROUND

The selection of suitable internal control genes is crucial for proper interpretation of real-time PCR data. Here we outline a strategy to identify housekeeping genes that could serve as suitable internal control for comparative analyses of gene expression data in breast cancer cell lines and tissues obtained by high throughput sequencing and quantitative real-time PCR (qRT-PCR).

METHODS

The strategy proposed includes the large-scale screening of potential candidate reference genes from RNA-seq data as well as their validation by qRT-PCR, and careful examination of reference data from the International Cancer Genome Consortium, The Cancer Genome Atlas and Gene Expression Omnibus repositories.

RESULTS

The identified set of reference genes, also called novel housekeeping genes that includes CCSER2, SYMPK, ANKRD17 and PUM1, proved to be less variable and thus potentially more accurate for research and clinical analyses of breast cell lines and tissue samples compared to the traditional housekeeping genes used to this end.

DISCUSSION

These results highlight the importance of a massive evaluation of housekeeping genes for their relevance as internal control for optimized intra- and inter-assay comparison of gene expression.

CONCLUSION

We developed a strategy to identify and evaluate the significance of housekeeping genes as internal control for the intra- and inter-assay comparison of gene expression in breast cancer that could be applied to other tumor types and diseases.

Human epithelial-type ovarian tumour marker beta-2-microglobulin is regulated by the TGF-β signaling pathway

Background

Beta-2-microglobulin (B2M), a light chain subunit of the major histocompatibility complex (MHC) class I complex, has been implicated in tumorigenesis. However, whether it is expressed in different epithelial-type ovarian tumours remains unknown. This study was performed to examine the expression of B2M in different histopathological types of ovarian tumours, to explore the function of B2M in ovarian cancer (OC) cells and to investigate the mechanisms underlying the regulation of B2M by the TGF-β signaling pathway.

Methods

B2M expression in normal ovarian tissues and epithelia-type ovarian tumours was detected by immunohistochemistry and Western blot, followed by the analysis of association with clinical features. OC cells were transfected with B2M-siRNA and cell proliferation, migration and invasion were determined by WST-1 assay, wound healing assay and Transwell invasion assay, respectively. The regulation of B2M by the TGF-β signaling pathway in OC cells was examined by Western blot, ELISA and qRT-PCR.

Results

We found that B2M was overexpressed in ovarian borderline and malignant tumours compared with benign tumours and normal controls, but was not associated with age, tumour size, lymph node metastasis and clinical stage. Knocking down of B2M led to a decrease in OC cell proliferation, migration and invasion. The expression of B2M was downregulated by TGF-β1 in OC cells, which was abolished in the presence of the inhibitor of TGF-β type I receptor.

Conclusion

Our findings suggest that B2M is a potential tissue biomarker and therapeutic target of borderline and malignant ovarian tumours and the dysregulation of B2M in these tumours may be mediated by the TGF-β signaling pathway.

Circulating Beta-2 Microglobulin and Risk of Cancer: The Atherosclerosis Risk in Communities Study (ARIC)

BACKGROUND

Serum β-2 microglobulin (B2M), a major histocompatibility complex class I molecule that is a biomarker of kidney filtration and increased cell turnover, is elevated at the time of diagnosis in hematological and some solid cancers. However, serum B2M was not examined prospectively as a marker for cancer risk. We hypothesized that in a population without a prior cancer diagnosis, serum B2M is associated with risk of cancer (n = 2,436), including colorectal (n = 255), lung (n = 298), breast (n = 424), and prostate (n = 524) cancers, and hematological (n = 176) malignancies.

METHODS

The analytical cohort (n = 12,300) was followed for incident cancers from 1990 through 2006. B2M (range, 0.9-57.8 mg/L) was measured in stored serum collected in 1990-1992. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals for cancer incidence and mortality in relation to quartiles of B2M.

RESULTS

Adjusting for age, sex, race, center, education, body mass index, smoking, aspirin, and hormone therapy (in women) and comparing highest to lowest B2M quartiles, HRs were 1.25 (1.06-1.47; Ptrend = 0.002) for total cancer risk and 2.21 (1.32-3.70; Ptrend=0.001) for colorectal cancer risk, with similar HRs for colon and rectal cancers. These associations remained after adjustment for an inflammatory biomarker, C-reactive protein, and after excluding the first three years of follow-up. Significant associations were also observed for mortality from total, lung, and hematological cancers.

CONCLUSIONS

These findings provide the first evidence that higher serum B2M is associated with increased colorectal cancer risk.

IMPACT

This study supports B2M as a potential biomarker for colorectal cancer risk. Cancer Epidemiol Biomarkers Prev; 25(4); 657-64. ©2016 AACR.

The number of polyploid giant cancer cells and epithelial-mesenchymal transition-related proteins are associated with invasion and metastasis in human breast cancer

Background

Previously, we reported that polyploid giant cancer cells (PGCCs) induced by cobalt chloride (CoCl₂) could have generated daughter cells with strong invasiveness and migration capabilities via asymmetric divisions. This study compared the expression of epithelial-mesenchymal transition (EMT)-related proteins, including E-cadherin, N-cadherin, and vimentin, between PGCCs and their daughter cells, and control breast cancer cell lines MCF-7 and MDA-MB-231. The clinicopathological significance of EMT-related protein expression in human breast cancer was analyzed.

Methods

Western blot was used to compare the expression levels of E-cadherin, N-cadherin, and vimentin in breast cancer lines MCF-7 and MDA-MB-231, between PGCCs with budding daughter cells and control breast cancer cells. Furthermore, 167 paraffin-embedded breast tumor tissue samples were analyzed, including samples obtained from 52 patients with primary breast cancer with lymph node metastasis (group I) and their corresponding lymph node metastatic tumors (group II), 52 patients with primary breast cancer without metastasis (group III), and 11 patients with benign breast lesions (group IV). The number of PGCCs was compared among these four groups.

Results

The number of PGCCs increased with the malignant grade of breast tumor. Group IIhad the highest number of PGCCs and the differences among group I, II, III and IV had statistically significance (P =0.000). In addition, the expression of E-cadherin (P = 0.000), N-cadherin (P = 0.000), and vimentin (P = 0.000) was significantly different among the four groups. Group II exhibited the highest expression levels of N-cadherin and vimentin and the lowest expression levels of E-cadherin.

Conclusions

These data suggest that the number of PGCCs and the EMT-related proteins E-cadherin, N-cadherin, and vimentin may be valuable biomarkers to assess metastasis in patients with breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0277-8) contains supplementary material, which is available to authorized users.

In-depth LC-MS/MS analysis of the chicken ovarian cancer proteome reveals conserved and novel differentially regulated proteins in humans

Ovarian cancer (OVC) remains the most lethal gynecological malignancy in the world due to the combined lack of early-stage diagnostics and effective therapeutic strategies. The development and application of advanced proteomics technology and new experimental models has created unique opportunities for translational studies. In this study, we investigated the ovarian cancer proteome of the chicken, an emerging experimental model of OVC that develops ovarian tumors spontaneously. Matched plasma, ovary, and oviduct tissue biospecimens derived from healthy, early-stage OVC, and late-stage OVC birds were quantitatively characterized by label-free proteomics. Over 2600 proteins were identified in this study, 348 of which were differentially expressed by more than twofold (p ≤ 0.05) in early- and late-stage ovarian tumor tissue specimens relative to healthy ovarian tissues. Several of the 348 proteins are known to be differentially regulated in human cancers including B2M, CLDN3, EPCAM, PIGR, S100A6, S100A9, S100A11, and TPD52. Of particular interest was ovostatin 2 (OVOS2), a novel 165-kDa protease inhibitor found to be strongly upregulated in chicken ovarian tumors (p = 0.0005) and matched plasma (p = 0.003). Indeed, RT-quantitative PCR and Western blot analysis demonstrated that OVOS2 mRNA and protein were also upregulated in multiple human OVC cell lines compared to normal ovarian epithelia (NOE) cells and immunohistochemical staining confirmed overexpression of OVOS2 in primary human ovarian cancers relative to non-cancerous tissues. Collectively, these data provide the first evidence for involvement of OVOS2 in the pathogenesis of both chicken and human ovarian cancer.