Differentiation of tumours of ductal and lobular origin: II. Genomics of invasive ductal and lobular breast carcinomas

Vascular Endothelial Growth Factor Expression by Immunohistochemistry as a Possible Indicator of Prognosis in Invasive Breast Carcinoma of No Special Type

Context

Angiogenesis, the formation of new blood vessels from preexisting vascular network, is essential for tumor growth and spread. Vascular endothelial growth factor (VEGF) is a potent angiogenic growth factor.

Aims

To assess the expression of VEGF in invasive carcinoma of no special type and its correlation with all the known prognostic factors of breast carcinoma.

Settings and Design

Descriptive.

Materials and Methods

Mastectomy specimens were studied noting the clinical details. The formalin-fixed tissues were subjected to routine processing and hematoxylin and eosin sections and studied extensively for all the histological prognostic factors. Representative sections from each case with the tumor were subjected to immunohistochemistry (IHC) staining with VEGF, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2/neu) antibodies.

Statistical Analysis Used

Descriptive statistics, Chi-square tests, contingency table analysis using SPSS for Windows.

Results

One hundred and twelve cases of invasive carcinoma of special type were studied to evaluate various clinicopathological parameters. The association of VEGF with clinicopathological parameters and all the known prognostic factors was studied to note its significance. VEGF overexpression was observed in 69% of the cases. It was noted that larger tumor size, higher histological grade, lymphovascular invasion, nodal involvement, tumor necrosis, high microvessel density, ER negativity, PR negativity, and HER2/neu positivity had a significant statistical association with VEGF overexpression.

Conclusions

We conclude that incorporating VEGF as a biomarker along with the known factors into a prognostic index will not only help predict clinical outcome more accurately, but also determines the patient who can be benefited with combinational therapy including anti-VEGF factors.

3'UTR-HLA-G polymorphisms and circulating sHLA-G are associated with breast cancer: Evidence from a meta-analysis

BACKGROUND

Human leukocyte antigen-G (HLA-G) gene polymorphisms and circulating sHLA-G have often been linked to the risk of breast cancer (BC). However, the results remain controversial. To resolve this issue, we performed a meta-analysis of HLA-G gene polymorphisms and sHLA-G levels in BC.

METHODS

We performed a meta-analysis on the association of HLA-G 14-bp Insertion/Deletion (Ins/Del) and HLA-G +3142 C/G polymorphisms with BC as well as the relationship between sHLA-G and the disease outcome.

RESULTS

Pooled analysis showed a statistically significant association between the HLA-G 14-bp Ins/Del polymorphism and BC susceptibility for the overall population and for Caucasians. The Del allele and genotypes with at least one copy of the Del allele presented significant risks for BC. For HLA-G +3142 C/G polymorphism, the G allele significantly decreased the risk of BC for the overall population and for Caucasians, indicating that the G allele was a protective factor against BC and that the C allele was a significant risk factor for BC. The meta-analysis revealed a significantly increased level of sHLA-G patients with BC compared to the control group for the overall population, Caucasians and Asians.

CONCLUSION

The present meta-analysis showed a major association of both HLA-G 14-bp Ins/Del and +3142 C/G polymorphisms with BC susceptibility, suggesting Del and C variants as highly significant risk factors for BC. The present study also showed significantly higher sHLA-G levels in patients with BC compared to healthy controls. Our pooled results suggested a critical role of HLA-G in BC, thereby providing evidence to use HLA-G as a biomarker and a therapeutic tool.

Evaluating the Association between CCR5delta32 Polymorphism (rs333) and the Risk of Breast Cancer in a Cohort of Iranian Population

Background

CC chemokine receptor 5 (CCR5) is introduced as an immune response modulator. The activity of CCR5 influences breast tumour development in a p53-dependent manner. This study aimed to investigate the frequency of CCR5delta32 and its association with the risk of breast cancer in 1038 blood samples in North East of Iran.

Methods

In this case-control study, we genotyped 570 control samples and 468 breast cancer patients by a gel electrophoresis-based gap-polymerase chain reaction (gap-PCR) method Mashhad, Iran. The data were analyzed using the SPSS software.

Results

Of 570 controls included, 542 (95.09%) had CCR5delta32 ^{wild/wild (W/W)} genotype, 28 samples (4.91%) had CCR5delta32 ^{wild/deletion (W/D)} genotype and none of them were CCR5delta32 ^{deletion/deletion (D/D)} genotype (0%). While 428 samples of patients (91.45%) had CCR5delta32 ^W/W genotype, 40 samples (8.55%) had CCR5delta32 ^W/D and CCR5delta32 ^D/D homozygous was nil (0%) amongst cases. All samples were in the Hardy-Weinberg equilibrium (P>0.05). According to the allele frequency, D allele, as a risky allele, in the cases was more than the control samples (0.0427 vs 0.0245, respectively) (P=0.0206). Hence, W/D genotype may confer a risk effect (OR=1.77, CI: 1.09-2.90; P=0.0206) compared with WW genotype between case and control groups.

Conclusion

There is a statistically significant association between CCR5W/D and breast cancer risk. CCR5 may be regarded as a target for the prevention of breast cancer in certain conditions such as interaction with p53 variants, which remains to be further investigated.

FEN1 -69G>A and +4150G>T polymorphisms and breast cancer risk

Flap endonuclease 1 (FEN1), a DNA repair protein, is important in preventing carcinogenesis. Two functional germ line variants -69G>A (rs174538) and +4150G>T (rs4246215) in the FEN1 gene have been associated with risk of various types of cancer. The aim of the present study was to evaluate the possible impact of FEN1 polymorphisms on risk of breast cancer (BC) in a sample of Iranian subjects. The FEN1 -69G>A and +4150G>T polymorphisms were analyzed in a case-control study that included 266 BC patients and 225 healthy females. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to genotype the variants. The findings demonstrated that the FEN1 -69G>A and +4150G>T polymorphisms were not associated with BC risk in co-dominant, dominant and recessive inheritance models. The findings indicated that GG/GT, GA/GG and GA/TT genotypes significantly decreased the risk of BC when compared with -69GG/+4150GG. Furthermore, haplotype analysis indicated that -69G/+4150T as well as -69A/+4150G significantly decreased the risk of BC compared with -69G/+4150G. Thus, these findings demonstrated that haplotypes of FEN1 -69G>A and +4150G>T polymorphisms decreased the risk of BC in an Iranian population. Further studies with larger sample sizes and different ethnicities are required to validate the present findings.

Association between Programmed Cell Death 6 Interacting Protein Insertion/Deletion Polymorphism and the Risk of Breast Cancer in a Sample of Iranian Population

It has been suggested that genetic factors contribute to patients' vulnerability to breast cancer (BC). The programmed cell death 6 interacting protein (PDCD6IP) encodes for a protein that is known to bind to the products of the PDCD6 gene, which is involved in the apoptosis pathway. The aim of this case-control study is to investigate the relationship between the PDCD6IP 15 bp insertion/deletion (I/D) polymorphism (rs28381975) and BC risk in an Iranian population. A total of 491 females, including 266 BC patients and 225 control subjects without cancer, were enrolled into the study. Our findings revealed that the PDCD6IP 15 bp I/D polymorphism decreased the risk of BC in codominant (OR = 0.44, 95% CI = 0.31-0.65, p < 0.0001, I/D versus DD; OR = 0.39, 95% CI = 0.17-0.88, p = 0.030, I/I versus DD) and dominant (OR = 0.44, 95% CI = 0.30-0.63, p < 0.0001, D/I + I/I versus D/D) tested inheritance models. Also, the PDCD6IP I allele significantly decreased the risk of BC (OR = 0.59, 95% CI = 0.45-0.78, p < 0.001) compared to the D allele.

Association between hTERT polymorphisms and the risk of breast cancer in a sample of Southeast Iranian population

BACKGROUND

Breast cancer (BC) is considered to be one of the most important causes of death worldwide, and it affects the Iranian female population a decade earlier than female in other parts of the world. Human telomerase reverse transcriptase (hTERT) is a main subunit of the telomerase complex. MNS16A is located downstream of the hTERT gene and is recognized as the regulator of hTERT promoter activity. The aim of the present study was to access the possible impact of hTERT variants on BC risk in an Iranian population in southeast Iran.

METHODS

A total of 491 subjects including 266 BC patients and 225 healthy women participated in the study. Polymerase chain reaction (PCR) was used to genotype the MNS16A variable number of tandem repeats and 177 bp ins/del polymorphisms in the hTERT gene. PCR-RFLP and ARMS-PCR were used to genotype hTERT rs2736098 and 2735940, respectively. The association between genotypes and BC was assessed by computing the odds ratio (OR) and 95% confidence intervals (95% CI) from logistic regression analyses. A p-value of <0.05 was considered statistically significant.

RESULTS

The MNS16A genotype frequency distribution in BC patients was: LL, 43.2%; LS, 51.1%; and SS, 5.7%, and in controls: LL, 29.5%; LS, 68.3%; and SS, 2.2%. The LS genotype decreased the risk of BC compared with LL (OR=0.51, 95% CI=0.35-0.75, p<0.001). The hTERT 177 bp ins/del polymorphism was not polymorphic in our population. All subjects had the ins/ins genotype. Our findings indicate that the MNS16A genotype and hTERT rs2736098 variant were associated with BC risk in the study. We also showed that the rs2736098 A/G polymorphism increased the risk of BC (OR=1.80, 95% CI=1.12-2.88, p=0.017, AG vs AA; OR=1.80, 95% CI=1.06-3.06, p=0.033, GG vs AA; OR=1.87, 95% CI=1.19-2.94, p=0.006, AG+GG vs AA). No significant association was found between the rs2735940 C/T variant and BC.

CONCLUSION

Our findings indicate that the MNS16A genotype and the hTERT rs2736098 variant influence the risk of BC in an Iranian population in southeast Iran.

Association between CCNE1 polymorphisms and the risk of breast cancer in a sample of southeast Iranian population

Cyclin E1 (CCNE1) is a key proto-oncogene. The present study aimed to investigate the effects of single nucleotide polymorphisms in CCNE1 on the risk of breast cancer (BC) in an Iranian population in southeast of Iran. A total of 491 subjects including 266 BC patients and 225 healthy control women were participated in the study. Genotyping of CCNE1 rs3218073 and 72010703 polymorphisms was done using allele-specific polymerase chain reaction (AS-PCR) and rs1406 by PCR-RFLP method.Our findings showed that rs1406 C/A polymorphism increased the risk of BC in codominant (OR 1.60, 95% CI 1.05-2.43, p=0.032 CA vs CC; OR 2.35, 95% CI 1.23-4.49, p=0.011 AA vs CC) and dominant (OR 1.69, 95% CI 1.22-2.56, p=0.012 CA+AA vs CC) inheritance models. The rs1406 A allele increased the risk of BC (OR 1.37, 95% CI 1.06-1.76, p=0.019) in comparison with C allele. On the other hand, CCNE1 rs72010703 (4-bp I/D) and rs3218073 polymorphisms did not show any significant association with BC. This study indicates that CCNE1 rs1406 polymorphism may contribute to BC risk.

Age at diagnosis and breast cancer survival in iran

Background. Tumour characteristics are the most important prognostic factors in breast cancer. Patient-related factors such as young age at diagnosis, obesity, and smoking behaviour may also modify disease outcome. Due to the absence of a unique definition for "young age breast cancer" and the resulting variation in disease management, findings on the association between young age and prognosis of breast cancer are controversial. Methods. This study included 1500 patients with a primary diagnosis of breast cancer in six Iranian hospitals from 5 provinces. We modelled the relative excess risk (RER) of breast cancer death to age at diagnosis and tumour characteristics. Results. Excess risks of death were observed for stage IV disease and poorly differentiated tumours: RER of 4.3 (95% CI: 1.05-17.65) and 3.4 (95% CI: 1.17-9.87), respectively. "Older" patients, particularly those aged 50 and over, presented more often with advanced and poorly differentiated tumours (P = 0.001). After adjustment for stage, histological grade, Her-2 expression, estrogen and progesterone receptors, and place of residency, breast cancer mortality was not significantly different across age groups. Conclusion. We conclude that there is no prognostic effect of age at diagnosis of breast cancer among breast cancer patients treated at cancer centres in different parts of Iran; young and relatively old women have similar risks of dying from breast cancer.

Discovery of diagnostic serum biomarkers of gastric cancer using proteomics

Gastric cancer has significant morbidity and mortality worldwide and locally. Good prognosis relies on an early diagnosis. However, this remains a challenge due to the lack of specific and sensitive serum biomarkers for early detection. Hence, there is a constant search for these biomarkers for screening purposes. Proteomic profiling enables a new approach to the discovery of biomarkers in disease. This review presents recent attempts in search of gastric cancer serum biomarker using proteomics. Different methodologies and different types of samples were employed by different groups of researchers. Major difficulties were encountered in the discovery processes, including interference from abundant proteins and continuous changing serum proteomes from different individuals.

Differential loss of heterozygosity profile on chromosome 3p in ductal and lobular breast carcinomas

The 2 main histologic types of infiltrating breast cancer, invasive lobular and invasive ductal carcinoma, are morphologically and clinically distinct. Studies revealed that different patterns of gene expression and loss of heterozygosity can also distinguish these 2 subtypes. A whole-genome study using single nucleotide polymorphism array found a significantly higher frequency of loss of heterozygosity on 3p in invasive ductal carcinoma when compared with invasive lobular carcinoma. In this study, we performed a loss of heterozygosity analysis of the 3p chromosome region in ductal and lobular breast tumors. Seven microsatellite markers were evaluated in a series of 136 sporadic breast cancer cases (118 invasive ductal carcinoma and 18 invasive lobular carcinoma) and correlated with clinical-histopathologic parameters from the patients. A significantly higher frequency of loss of heterozygosity was observed in invasive ductal carcinoma (65.3%) when compared with invasive lobular carcinoma (38.9%). When the markers were analyzed separately, loss of heterozygosity at 3 of them, D3S1307 in 3p26.3, D3S1286 in 3p24.3, and D3S1300 in 3p14.2, were significantly more frequent in ductal than in lobular tumors. D3S1307 marker showed the highest frequency of loss of heterozygosity in invasive ductal carcinoma (46.2%), and associations between loss of this marker and loss of estrogen and progesterone receptors were found in these samples. Our results confirm the observations that invasive ductal carcinoma has a higher frequency of loss of heterozygosity events across the 3p region than invasive lobular carcinoma and show that specific losses on 3p26.3, 3p24.3, and 3p14.2 regions are more frequent in ductal than in lobular tumors. We discuss our data in relation to the known tumor suppressor genes that are mapped at the 3p loci investigated and their present relevant roles in breast cancer.

THBS4, a novel stromal molecule of diffuse-type gastric adenocarcinomas, identified by transcriptome-wide expression profiling

Gastric adenocarcinomas can be divided into two major histological types, the diffuse and intestinal type (Laurén classification). Since they diverge in many clinical and molecular characteristics, it is widely accepted that they represent distinct disease entities that may benefit from different therapeutic approaches. Gene expression profiling studies have identified numerous genes that are differentially expressed between them. However, none of these studies covered the whole transcriptome and the published gene lists reveal little overlap, raising the need for further, more comprehensive analyses. Here, we present the first transcriptome-wide expression profiling study comparing the two types (diffuse n=19, intestinal n=24), which identified >1000 genes that are differentially expressed. Among them, thrombospondin 4 (THBS4) showed the strongest correlation to histological type, with vast overexpression in the diffuse type. Quantitative real-time PCR validated this strong overexpression and revealed that intestinal tumors generally lack THBS4 expression. Immunohistochemistry demonstrated THBS4 overexpression on the protein level (n=10) and localized THBS4 to the stromal aspect. Its expression was primarily observed within the extracellular matrix surrounding the tumor cells, with the highest intensities found in regions of high tumor cell density and invasion. Intestinal tumors and matched non-neoplastic gastric epithelium and stroma did not feature any relevant THBS4 expression in a preliminary selection of analyzed cases (n=5). Immunohistochemical colocalization and in vitro studies revealed that THBS4 is expressed and secreted by cancer-associated fibroblasts. Furthermore, we show that THBS4 transcription in fibroblasts is stimulated by tumor cells. This study is the first to identify THBS4 as a powerful marker for diffuse-type gastric adenocarcinomas and to provide an initial characterization of its expression in the course of this disease.

ADAM33 gene silencing by promoter hypermethylation as a molecular marker in breast invasive lobular carcinoma

Background

ADAM33 protein is a member of the family of transmembrane glycoproteins composed of multidomains. ADAM family members have different activities, such as proteolysis and adhesion, making them good candidates to mediate the extracellular matrix remodelling and changes in cellular adhesion that characterise certain pathologies and cancer development. It was reported that one family member, ADAM23, is down-regulated by promoter hypermethylation. This seems to correlate with tumour progression and metastasis in breast cancer. In this study, we explored the involvement of ADAM33, another ADAM family member, in breast cancer.

Methods

First, we analysed ADAM33 expression in breast tumour cell lines by RT-PCR and western blotting. We also used 5-aza-2'-deoxycytidine (5azadCR) treatment and DNA bisulphite sequencing to study the promoter methylation of ADAM33 in breast tumour cell lines. We evaluated ADAM33 methylation in primary tumour samples by methylation specific PCR (MSP). Finally, ADAM33 promoter hypermethylation was correlated with clinicopathological data using the chi-square test and Fisher's exact test.

Results

The expression analysis of ADAM33 in breast tumour cell lines by RT-PCR revealed gene silencing in 65% of tumour cell lines. The corresponding lack of ADAM33 protein was confirmed by western blotting. We also used 5-aza-2'-deoxycytidine (5-aza-dCR) demethylation and bisulphite sequencing methodologies to confirm that gene silencing is due to ADAM33 promoter hypermethylation. Using MSP, we detected ADAM33 promoter hypermethylation in 40% of primary breast tumour samples. The correlation between methylation pattern and patient's clinicopathological data was not significantly associated with histological grade; tumour stage (TNM); tumour size; ER, PR or ERBB2 status; lymph node status; metastasis or recurrence. Methylation frequency in invasive lobular carcinoma (ILC) was 76.2% compared with 25.5% in invasive ductal carcinoma (IDC), and this difference was statistically significant (p = 0.0002).

Conclusion

ADAM33 gene silencing may be related to the discohesive histological appearance of ILCs. We suggest that ADAM33 promoter methylation may be a useful molecular marker for differentiating ILC and IDC.

Thrombospondins in cancer

The thrombospondins (TSPs) are a family of five proteins that are involved in the tissue remodeling that is associated with embryonic development, wound healing, synaptogenesis, and neoplasia. These proteins mediate the interaction of normal and neoplastic cells with the extracellular matrix and surrounding tissue. In the tumor microenvironment, TSP-1 has been shown to suppress tumor growth by inhibiting angiogenesis and by activating transforming growth factor beta. TSP-1 inhibits angiogenesis through direct effects on endothelial cell migration and survival, and through effects on vascular endothelial cell growth factor bioavailability. In addition, TSP-1 may affect tumor cell function through interaction with cell surface receptors and regulation of extracellular proteases. Whereas the role of TSP-1 in the tumor microenvironment is the best characterized, the other TSPs may have similar functions. (Part of a Multi-author Review).