Breast cancer is a promising target for vaccination using cancer-testis antigens known to elicit immune responses

Diagnostic value of serum tumor-associated autoantibodies in esophageal cancer

Aim: To explore the application value of serum autoantibodies in the early diagnosis of esophageal cancer. Materials & methods: A total of 130 patients with esophageal cancer and 110 controls were included and tested by ELISA. Results: According to the receiver operating characteristic curve, total sensitivity is 83.08%, total specificity is 72.73%. A nomogram was established based on the positive judgment standard, the area under the receiver operating characteristic curve was calculated to be 0.880 after verification with the calibration curve. A 2-week follow-up analysis found compared with the preoperative control, the postoperative model integral value will significantly decrease. Conclusion: The combination of serum autoantibody groups has certain clinical application value in the early diagnosis of esophageal cancer and can be used as an auxiliary index for early diagnosis.

Metformin: The Answer to Cancer in a Flower? Current Knowledge and Future Prospects of Metformin as an Anti-Cancer Agent in Breast Cancer

Interest has grown in studying the possible use of well-known anti-diabetic drugs as anti-cancer agents individually or in combination with, frequently used, chemotherapeutic agents and/or radiation, owing to the fact that diabetes heightens the risk, incidence, and rapid progression of cancers, including breast cancer, in an individual. In this regard, metformin (1, 1-dimethylbiguanide), well known as ‘Glucophage’ among diabetics, was reported to be cancer preventive while also being a potent anti-proliferative and anti-cancer agent. While meta-analysis studies reported a lower risk and incidence of breast cancer among diabetic individuals on a metformin treatment regimen, several in vitro, pre-clinical, and clinical studies reported the efficacy of using metformin individually as an anti-cancer/anti-tumor agent or in combination with chemotherapeutic drugs or radiation in the treatment of different forms of breast cancer. However, unanswered questions remain with regards to areas such as cancer treatment specific therapeutic dosing of metformin, specificity to cancer cells at high concentrations, resistance to metformin therapy, efficacy of combinatory therapeutic approaches, post-therapeutic relapse of the disease, and efficacy in cancer prevention in non-diabetic individuals. In the current article, we discuss the biology of metformin and its molecular mechanism of action, the existing cellular, pre-clinical, and clinical studies that have tested the anti-tumor potential of metformin as a potential anti-cancer/anti-tumor agent in breast cancer therapy, and outline the future prospects and directions for a better understanding and re-purposing of metformin as an anti-cancer drug in the treatment of breast cancer.

Prognostic roles of MAGE family members in breast cancer based on KM-Plotter Data

Breast cancer is the second leading cause of cancer-associated mortality among women worldwide, and the prevalence and mortality rates associated with this disease are high in Western countries. The melanoma-associated antigen (MAGE) family proteins are well-known tumor-specific antigens; this family includes >60 proteins that serve an important part in cell cycle withdrawal, neuronal differentiation and apoptosis. The aim of the present study was to identify a biomarker within the MAGE family that is specific for breast cancer. In the present study, the prognostic role of MAGE mRNA expression was investigated in patients with breast cancer using the Kaplan-Meier plotter database. The prognostic value of MAGE members in the different intrinsic subtypes of breast cancer was further investigated, as well as the clinicopathological features of the disease. The results of the present study indicated that patients with breast cancer that had high mRNA expression levels of MAGEA5, MAGEA8, MAGEB4 and MAGEB6 had an improved relapse-free survival, whereas those with high mRNA expression levels of MAGEB18 and MAGED4 did not. These results suggested that MAGEA5, MAGEA8, MAGEB4 and MAGEB6 may have roles as tumor suppressors in the occurrence and development of breast cancer, whereas MAGEB18 and MAGED4 may possess carcinogenic potential. MAGED2, MAGED3 and MAGEF1 had different effects depending on the type of breast cancer. In particular, high MAGEC3 mRNA expression was associated with worse RFS in lymph node-positive breast cancer, but with improved RFS in lymph node-negative breast cancer. In patients with wild-type TP53 and patients with different pathological grades of breast cancer, MAGEE2, MAGEH1 and MAGEL2 were more worthy of attention as potential prognostic factors. The results of the present study may help to elucidate the role of MAGE family members in the development of breast cancer, and may promote further research that identifies MAGE-targeting reagents for the treatment of breast cancer.

High expression of ACTL8 is poor prognosis and accelerates cell progression in head and neck squamous cell carcinoma

Actin‑like protein 8 (ACTL8) is a member of the cancer‑testis antigens (CTA) family, which is mainly localized in the cytoplasm and generally expressed in the testis. The association between ACTL8 and various types of cancer, including glioblastoma and breast cancer, has previously been demonstrated. However, whether ACTL8 is involved in the development of head and neck squamous cell carcinoma (HNSCC) remains unknown. In the present study, the expression of ACTL8 in patients with HNSCC was analyzed in The Cancer Genome Atlas (TCGA) dataset, clinical tissues and cell lines. Correlations between the expression levels of ACTL8 and HNSCC clinical outcomes were analyzed with the Kaplan‑Meier method and the Cox proportional hazards model. Cell Counting Kit‑8, plate colony formation and Transwell assays were used to assess the effects of ACTL8 interference on the proliferation, migration and invasion of HNSCC PCI‑13 cells. Reverse transcription‑quantitative polymerase chain reaction and western blotting were used to evaluate the expression levels of ACTL8 in PCI‑13 cells. Furthermore, alterations in the expression levels of key proteins in the phosphatidylinositol‑4,5‑bisphosphate 3‑kinase (PI3K)/RAC‑α protein kinase B (AKT) signaling pathway were determined by western blotting. Increased expression of ACTL8 in HNSCC was observed in TCGA dataset, cancerous tissue samples and HNSCC cell line. Cox regression analysis indicated that ACTL8 expression could be regarded as an independent prognostic factor for HNSCC, since increased expression of ACTL8 was associated with a poor prognosis. Knocking down ACTL8 markedly inhibited the proliferation, invasion and migration of PCI‑13 cells. Additionally, activation of the PI3K/AKT signaling pathway was suppressed by reduced expression levels of certain key proteins in this pathway. The present data indicate that ACTL8 serves a role in the progression and clinical prognosis of HNSCC. Therefore, ACTL8 may be a potential prognostic marker and novel therapeutic target for HNSCC.

Challenges and perspectives in the treatment of diabetes associated breast cancer

Type 2 diabetes mellitus is one of the most common chronic disease worldwide and affects all cross-sections of the society including children, women, youth and adults. Scientific evidence has linked diabetes to higher incidence, accelerated progression and increased aggressiveness of different cancers. Among the different forms of cancer, research has reinforced a link between diabetes and the risk of breast cancer. Some studies have specifically linked diabetes to the highly aggressive, triple negative breast cancers (TNBCs) which do not respond to conventional hormonal/HER2 targeted interventions, have chances of early recurrence, metastasize, tend to be more invasive in nature and develop drug resistance. Commonly used anti-diabetic drugs, such as metformin, have recently gained importance in the treatment of breast cancer due to their proposed anti-cancer properties. Here we discuss the link between diabetes and breast cancer, the metabolic disturbances in diabetes that support the development of breast cancer, the challenges involved and future perspective and directions. We link the three main metabolic disturbances (dyslipidemia, hyperinsulinemia and hyperglycemia) that occur in diabetes to potential aberrant molecular pathways that may lead to the development of an oncogenic phenotype of the breast tissue, thereby leading to acceleration of cell growth, proliferation, migration, inflammation, angiogenesis, EMT and metastasis and inhibition of apoptosis in breast cancer cells. Furthermore, managing diabetes and treating cancer using a combination of anti-diabetic and classical anti-cancer drugs should prove to be more efficient in the treatment diabetes associated cancers.

Cancer testis antigens as immunogenic and oncogenic targets in breast cancer

Breast cancer cells frequently express tumor-associated antigens that can elicit immune responses to eradicate cancer. Cancer-testis antigens (CTAs) are a group of tumor-associated antigens that might serve as ideal targets for cancer immunotherapy because of their cancer-restricted expression and robust immunogenicity. Previous clinical studies reported that CTAs are associated with negative hormonal status, aggressive tumor behavior and poor survival. Furthermore, experimental studies have shown the ability of CTAs to induce both cellular and humoral immune responses. They also demonstrated the implication of CTAs in promoting cancer cell growth, inhibiting apoptosis and inducing cancer cell invasion and migration. In the current review, we attempt to address the immunogenic and oncogenic potential of CTAs and their current utilization in therapeutic interventions for breast cancer.

Breast cancer genomics and immuno-oncological markers to guide immune therapies

There is an increasing awareness of the importance of tumor - immune cell interactions to the evolution and therapy responses of breast cancer (BC). Not surprisingly, numerous studies are currently assessing the clinical value of immune modulation for BC patients. However, till now durable clinical responses are only rarely observed. It is important to realize that BC is a heterogeneous disease comprising several histological and molecular subtypes, which cannot be expected to be equally immunogenic and therefore not equally sensitive to single immune therapies. Here we review the characteristics of infiltrating leukocytes in healthy and malignant breast tissue, the prognostic and predictive values of immune cell subsets across different BC subtypes and the various existing immune evasive mechanisms. Furthermore, we describe the presence of certain groups of antigens as putative targets for treatment, evaluate the outcomes of current clinical immunotherapy trials, and finally, we propose a strategy to better implement immuno-oncological markers to guide future immune therapies in BC.

Roles of cancer/testis antigens (CTAs) in breast cancer

Breast cancer is the most common cancer diagnosed and is the second leading cause of cancer death among women in the US. For breast cancer, early diagnosis and efficient therapy remains a significant clinical challenge. Therefore, it is necessary to identify novel tumor associated molecules to target for biomarker development and immunotherapy. In this regard, cancer testis antigens (CTAs) have emerged as a potential clinical biomarker targeting immunotherapy for various malignancies due to the nature of its characteristics. CTAs are a group of tumor associated antigens (TAAs) that display normal expression in immune-privileged organs, but display aberrant expression in several types of cancers, particularly in advanced cancers. Investigation of CTAs for the clinical management of breast malignancies indicates that these TAAs have potential roles as novel biomarkers, with increased specificity and sensitivity compared to those currently used in the clinic. Moreover, TAAs could be therapeutic targets for cancer immunotherapy. This review is an attempt to address the promising CTAs in breast cancer and their possible clinical implications as biomarkers and immunotherapeutic targets with particular focus on challenges and future interventions.

Ectopic Expression of Testis Germ Cell Proteins in Cancer and Its Potential Role in Genomic Instability

Genomic instability is a hallmark of human cancer and an enabling factor for the genetic alterations that drive cancer development. The processes involved in genomic instability resemble those of meiosis, where genetic material is interchanged between homologous chromosomes. In most types of human cancer, epigenetic changes, including hypomethylation of gene promoters, lead to the ectopic expression of a large number of proteins normally restricted to the germ cells of the testis. Due to the similarities between meiosis and genomic instability, it has been proposed that activation of meiotic programs may drive genomic instability in cancer cells. Some germ cell proteins with ectopic expression in cancer cells indeed seem to promote genomic instability, while others reduce polyploidy and maintain mitotic fidelity. Furthermore, oncogenic germ cell proteins may indirectly contribute to genomic instability through induction of replication stress, similar to classic oncogenes. Thus, current evidence suggests that testis germ cell proteins are implicated in cancer development by regulating genomic instability during tumorigenesis, and these proteins therefore represent promising targets for novel therapeutic strategies.

AKAP3 correlates with triple negative status and disease free survival in breast cancer

BACKGROUND

Cancer-testis antigens are among the new promising biomarkers, especially for targeted therapy. Aberrant and specific expression of these proteins has been reported in some tumor tissues. Also understanding their differential role in normal and cancer tissues may introduce them as new candidates for biomarker in cancer.

METHODS

AKAP3 expression was investigated in 162 tumors, normal adjacent and normal tissues of the breast with Real-Time PCR. Also the correlation between the gene expression and clinico-pathologic features of the tumors and treatment regimen was evaluated.

RESULTS

There was an association between lack of AKAP3 expression in tumor tissues and triple negative status (p=. 03). There was also a correlation between lack of this marker and tumor size (p = .01) and stage (p = .04). Lack of AKAP3 in normal adjacent tissues was associated with poor prognosis. Kaplan Meier plot demonstrated a remarkable better 5-year disease free survival in AKAP3 positive normal adjacent group.

CONCLUSIONS

It was found that this relationship is originated from the difference in AKAP3 expression, not therapy distribution between two groups of patients. Thus, it may be a proper biomarker candidate for triple negative breast cancer patients. Also, testing AKAP3 in normal tissue of the patients may be used to predict the outcome of the treatment.

Cancer-testis genes as candidates for immunotherapy in breast cancer

Cancer-testis (CT) antigens are tumor-associated antigens attracting immunologists for their possible application in the immunotherapy of cancer. Several clinical trials have assessed their therapeutic potentials in cancer patients. Breast cancers, especially triple-negative cancers are among those with significant expression of CT genes. Identification of CT genes with high expression in cancer patients is the prerequisite for any immunotherapeutic approach. CT genes have gained attention not only for immunotherapy of cancer patients, but also for immunoprevention in high-risk individuals. Many CT genes have proved to be immunogenic in breast cancer patients suggesting the basis for the development of polyvalent vaccines.

Potential use of vaccines in the primary prevention of breast cancer in high-risk patients

Cancer vaccines are an emerging therapeutic and prophylactic modality that may play a more important role in cancer prevention and treatment in the future. Therapeutic cancer vaccines are designed to generate a targeted, immune-mediated antitumor response. Successful prophylactic vaccines are those against oncogenic viral infections, such as the human papillomavirus and cervical cancer. However, a tough challenge for the majority of tumor vaccines is the self-nature of tumor antigens. Ongoing studies are investigating methods to enhance vaccine strategies including immune-modulating agents. The present review analyzes the potential use of vaccines in the primary prevention of breast cancer, focusing on the recent extension of vaccine target selection to self-proteins that are overexpressed during the early stages of tumor development but whose expression no longer occurs as we age, a feature that may avoid clinically significant autoimmune sequelae.

Cancer testis antigens and NY-BR-1 expression in primary breast cancer: prognostic and therapeutic implications

BACKGROUND

Cancer-testis antigens (CTA) comprise a family of proteins, which are physiologically expressed in adult human tissues solely in testicular germ cells and occasionally placenta. However, CTA expression has been reported in various malignancies. CTAs have been identified by their ability to elicit autologous cellular and or serological immune responses, and are considered potential targets for cancer immunotherapy. The breast differentiation antigen NY-BR-1, expressed specifically in normal and malignant breast tissue, has also immunogenic properties. Here we evaluated the expression patterns of CTAs and NY-BR-1 in breast cancer in correlation to clinico-pathological parameters in order to determine their possible impact as prognostic factors.

METHODS

The reactivity pattern of various mAbs (6C1, MA454, M3H67, 57B, E978, GAGE #26 and NY-BR-1 #5) were assessed by immunohistochemistry in a tissue micro array series of 210 randomly selected primary invasive breast cancers in order to study the diversity of different CTAs (e.g. MAGE-A, NY-ESO-1, GAGE) and NY-BR-1. These expression data were correlated to clinico-pathological parameters and outcome data including disease-free and overall survival.

RESULTS

Expression of at least one CTA was detectable in the cytoplasm of tumor cells in 37.2% of the cases. NY-BR-1 expression was found in 46.6% of tumors, respectively. Overall, CTA expression seemed to be linked to adverse prognosis and M3H67 immunoreactivity specifically was significantly correlated to shorter overall and disease-free survival (p=0.000 and 0.024, respectively).

CONCLUSIONS

Our findings suggest that M3H67 immunoreactivity could serve as potential prognostic marker in primary breast cancer patients. The exclusive expression of CTAs in tumor tissues as well as the frequent expression of NY-BR-1 could define new targets for specific breast cancer therapies.

Cancer testes antigens in breast cancer: biological role, regulation, and therapeutic applicability

Breast cancer remains one of the leading causes of death among women across the world. The last few decades have seen significant reduction in mortality owing to earlier detection and better adjuvant treatments that were developed based on clinical staging and morphological features. As these treatments have evolved, the heterogeneity of breast cancer poses a new challenge, since there is no standard gold-therapy suitable for all tumors of the mammary gland. Therefore, contemporary management and research efforts are directed toward specific prognostic and predictive molecular signatures that can guide targeted individualized therapy. The goal of ongoing research in this field is to identify specific molecular targets for developing novel therapeutic approaches. These targets can also serve to improve screening of breast cancer. This review focuses on the role of cancer testis antigens (CTAs) in breast carcinogenesis and explores the potential for development of targeted screening and therapeutic approaches. Normally found in the testes, these antigens are highly correlative with cancers of the breast, skin, and ovaries. These implications have been further corroborated through uncovering the interaction of CTAs with genes and proteins involved in tumor suppression and homeostasis like p53. There is some evidence that these genes can be targeted for early detection in addition to being candidates for cancer immunotherapy.

New hypotheses for large-scale epigenome alterations in somatic cancer cells: a role for male germ-cell-specific regulators

Oncogenic cell transformation is consistently associated with alterations of the cell epigenome leading to aberrant gene repression and activation. Some of these events, such as the DNA-methylation-based silencing of tumor suppressor genes, are considered to be oncogenic themselves. A much less-studied consequence of these epigenetic misregulations is the abnormal activation of tissue-specific genes in precancerous and transformed cells. Here, we explore the idea that the aberrant expression of germ-cell-specific genes in somatic cancer cells could contribute to malignant cell transformation and cancer progression. Indeed, a significant number of papers have reported the abnormal activation of germ cell-specific genes in various somatic cancers (known as cancer testis [C/T] antigens or factors). Although in most cases the physiological function of these genes remains unknown, functional investigations suggest that they can act as potent genome, epigenome and cellular reorganizers. Hence, in view of the existing literature, we discuss the hypothesis that C/T activation in somatic cells is not only a consequence of global epigenetic deregulation, but also a cause of further large-scale alterations of the epigenome, which themselves have direct oncogenic consequences for the affected cells. Finally, we highlight the fact that C/T factors have the potential to serve as valuable markers for cancer detection, as well as provide promising targets for developing new therapeutical strategies.

Melanoma antigen family A identified by the bimodality index defines a subset of triple negative breast cancers as candidates for immune response augmentation

BACKGROUND

Molecular markers displaying bimodal expression distribution can reveal distinct disease subsets and may serve as prognostic or predictive markers or represent therapeutic targets. Oestrogen (ER) and human epidermal growth factor receptor 2 (HER2) receptors are strongly bimodally expressed genes in breast cancer.

MATERIAL AND METHODS

We applied a novel method to identify bimodally expressed genes in 394 triple negative breast cancers (TNBC). We identified 133 bimodally expressed probe sets (128 unique genes), 69 of these correlated to previously reported metagenes that define molecular subtypes within TNBC including basal-like, molecular-apocrine, claudin-low and immune cell rich subgroups but 64 probe sets showed no correlation with these features.

RESULTS

The single most prominent functional group among these uncorrelated genes was the X chromosome derived Cancer/Testis Antigens (CT-X) including melanoma antigen family A (MAGE-A) and Cancer/Testis Antigens (CTAG). High expression of CT-X genes correlated with worse survival in multivariate analysis (HR 2.02, 95% CI 1.27-3.20; P=0.003). The only other significant variable was lymph node status. The poor prognosis of patients with high MAGE-A expression was ameliorated by the concomitant high expression of immune cell metagenes (HR 1.87, 95% CI 0.96-3.64; P=0.060), whereas the same immune metagene had lesser prognostic value in TNBC with low MAGE-A expression.

CONCLUSIONS

MAGE-A antigen defines a very aggressive subgroup of TNBC; particularly in the absence of immune infiltration in the tumour microenvironment. These observations suggest a therapeutic hypothesis; TNBC with MAGE-A expression may benefit the most from further augmentation of the immune response. Novel immune stimulatory drugs such as (anti-cytotoxic T-lymphocyte antigen-4 CTLA-4) directed therapies provide a realistic opportunity to directly test this hypothesis in the clinic.

Expression of cancer testis antigens in human BRCA-associated breast cancers: potential targets for immunoprevention?

INTRODUCTION

Novel breast cancer risk-reducing strategies for individuals with germline mutations of the BRCA1 and/or BRCA2 genes are urgently needed. Identification of antigenic targets that are expressed in early cancers, but absent in normal breast epithelium of these high-risk individuals, could provide the basis for the development of effective immunoprophylactic strategies. Cancer testis (CT) antigens are potential candidates because their expression is restricted to tumors, and accumulating data suggest that they play important roles in cellular proliferation, stem cell function, and carcinogenesis. The objective of this study was to examine the expression of CT antigens and their frequency in BRCA-associated breast cancers.

METHODS

Archived breast cancer tissues (n = 26) as well as morphologically normal breast tissues (n = 7) from women carrying deleterious BRCA 1 and/or 2 mutations were obtained for antigen expression analysis by immunohistochemistry. Expression of the following CT antigens was examined: MAGE-A1, MAGE-A3, MAGE-A4, MAGE-C1.CT7, NY-ESO-1, MAGE-C2/CT10, and GAGE.

RESULTS

CT antigens were expressed in 16/26 (61.5%, 95% CI 43-80%) of BRCA-associated cancers, including in situ tumors. Thirteen of twenty-six (50%) breast cancers expressed two or more CT antigens; three cancers expressed all seven CT antigens. MAGE-A was expressed in 13/26 (50%) of cancers, NY-ESO-1 was expressed in 10/26 (38%) of tumors. In contrast, none of the CT antigens were expressed in adjacent or contralateral normal breast epithelium (P = 0.003).

CONCLUSIONS

We report a high CT antigen expression rate in BRCA-associated breast cancer as well as the lack of expression of these antigens in benign breast tissue of carriers, identifying CT antigens as potential vaccine targets for breast cancer prevention in these high-risk individuals.

CT-X antigen expression in human breast cancer

Cancer/testis (CT) genes are predominantly expressed in human germ line cells, but not somatic tissues, and frequently become activated in different cancer types. Several CT antigens have already proved to be useful biomarkers and are promising targets for therapeutic cancer vaccines. The aim of the present study was to investigate the expression of CT antigens in breast cancer. Using previously generated massively parallel signature sequencing (MPSS) data, together with 9 publicly available gene expression datasets, the expression pattern of CT antigens located on the X chromosome (CT-X) was interrogated. Whereas a minority of unselected breast cancers was found to contain CT-X transcripts, a significantly higher expression frequency was detected in estrogen and progesterone receptor (ER) negative breast cancer cell lines and primary breast carcinomas. A coordinated pattern of CT-X antigen expression was observed, with MAGEA and NY-ESO-1/CTAG1B being the most prevalent antigens. Immunohistochemical staining confirmed the correlation of CT-X antigen expression and ER negativity in breast tumors and demonstrated a trend for their coexpression with basal cell markers. Because of the limited therapeutic options for ER-negative breast cancers, vaccines based on CT-X antigens might prove to be useful.