Kaiso (ZBTB33) subcellular partitioning functionally links LC3A/B, the tumor microenvironment, and breast cancer survival

The use of digital pathology for the histomorphologic profiling of pathological specimens is expanding the precision and specificity of quantitative tissue analysis at an unprecedented scale; thus, enabling the discovery of new and functionally relevant histological features of both predictive and prognostic significance. In this study, we apply quantitative automated image processing and computational methods to profile the subcellular distribution of the multi-functional transcriptional regulator, Kaiso (ZBTB33), in the tumors of a large racially diverse breast cancer cohort from a designated health disparities region in the United States. Multiplex multivariate analysis of the association of Kaiso’s subcellular distribution with other breast cancer biomarkers reveals novel functional and predictive linkages between Kaiso and the autophagy-related proteins, LC3A/B, that are associated with features of the tumor immune microenvironment, survival, and race. These findings identify effective modalities of Kaiso biomarker assessment and uncover unanticipated insights into Kaiso’s role in breast cancer progression.

Through automated image analysis, Singhal et al quantify nuclear versus cytoplasmic distribution of the Kaiso transcription factor in breast cancer patient tissue. They find that Kaiso distribution correlates with breast cancer subtype and overall survival, and discover a link between cytoplasmic Kaiso and autophagy marker LC3.

The impact of EGFR gene polymorphisms on the response and toxicity derived from neoadjuvant chemotherapy for breast cancer

Background

Neoadjuvant chemotherapy is usually used for treating locally advanced breast cancer. However, not all patients achieve pathologic complete response (pCR). In this study, we selected two epidermal growth factor receptor (EGFR) single nucleotide polymorphism (SNP) sites, rs1468727 and rs845552, to investigate the association between the genotypes and the response and toxicity derived from neoadjuvant chemotherapy for breast cancer.

Methods

All participants took part in clinical trial SHPD001 and SHPD002. For univariate analyses, the association between SNP and pCR or toxicity was analyzed by Chi-square or Fisher's exact test. For multivariate analyses, logistic regression was used instead.

Results

In all, one hundred and eighteen patients were enrolled. We found that the frequency of AA genotype in rs845552 was higher than that of other genotypes in HER2-positive breast cancer (AA vs. AG, P=0.039; AA vs. GG, P=0.005; AA vs. AG+GG, P=0.009). Multivariate logistic regression analyses showed that pCR was more difficult to be achieved in patients with a CT genotype in rs1468727 compared to those with a CC+TT genotype (OR =0.288, 95% CI: 0.109-0.762, P=0.012) or a CC genotype (OR =0.254, 95% CI: 0.076-0.849, P=0.026). Moreover, we demonstrated that both rs1468727 and rs845552 were associated with toxicity that results in complications such as increased total bilirubin, skin rash, peripheral neuropathy, and alopecia (P<0.05).

Conclusions

Our study reported for the first time, that in treating breast cancer with neoadjuvant chemotherapy, EGFR SNP rs1468727 is associated with treatment response, and that both rs1468727 and rs845552 are related to treatment-derived toxicity. In addition, we also found that rs845552 may be related to the status of HER2 in breast cancer.

Autophagy and Apoptotic Crosstalk: Mechanism of Therapeutic Resistance in HER2-Positive Breast Cancer

While breast cancer patients benefit from the use of HER2 inhibitors, many fail therapy and become resistant to treatment, indicating a critical need to prevent treatment failure. A number of studies have emerged that highlight the catabolic process of autophagy in breast cancer as a mechanism of resistance to chemotherapy and targeted inhibitors. Furthermore, recent research has begun to dissect how autophagy signaling crosstalks with apoptotic signaling. Thus, a possible strategy in fighting resistance is to couple targeting of apoptotic and autophagy signaling pathways. In this review, we discuss how cellular response by autophagy circumvents cell death to promote resistance of breast cancers to HER2 inhibitors, as well as the potential avenues of therapeutic intervention.

Simultaneous copy number gains of NUPR1 and ERBB2 predicting poor prognosis in early-stage breast cancer

Background

The full extent of chromosomal alterations and their biological implications in early breast carcinogenesis has not been well examined. In this study, we aimed to identify chromosomal alterations associated with poor prognosis in early-stage breast cancers (EBC).

Methods

A total of 145 EBCs (stage I and II) were examined in this study. We analyzed copy number alterations in a discovery set of 48 EBCs using oligoarray-comparative genomic hybridization. In addition, the recurrently altered regions (RARs) associated with poor prognosis were validated using an independent set of 97 EBCs.

Results

A total of 23 RARs were defined in the discovery set. Six were commonly detected in both stage I and II groups (> 50%), suggesting their connection with early breast tumorigenesis. There were gains on 1q21.2-q21.3, 8q24.13, 8q24.13-21, 8q24.3, and 8q24.3 and a loss on 8p23.1-p22. Among the 23 RARs, copy number gains on 16p11.2 (NUPR1) and 17q12 (ERBB2) showed a significant association with poor survival (P = 0.0186 and P = 0.0186, respectively). The patients simultaneously positive for both gains had a significantly worse prognosis (P = 0.0001). In the independent replication, the patients who were double-positive for NUPR1-ERBB2 gains also had a significantly poorer prognosis on multivariate analysis (HR = 7.31, 95% CI 2.65-20.15, P = 0.0001).

Conclusions

The simultaneous gain of NUPR1 and ERBB2 can be a significant predictor of poor prognosis in EBC. Our study will help to elucidate the molecular mechanisms underlying early-stage breast cancer tumorigenesis. This study also highlights the potential for using combinations of copy number alterations as prognosis predictors for EBC.

Caveolin-1 overexpression is associated with simultaneous abnormal expression of the E-cadherin/α-β catenins complex and multiple ErbB receptors and with lymph nodes metastasis in head and neck squamous cell carcinomas

The presence of lymph node metastases is one of the most important prognostic indicators in head and neck squamous cell carcinomas (HNSCCs). An alteration of the E-cadherin-catenins complex and EGFR is essential for the invasiveness of cancer cells. Caveolin-1, the major structural protein of the caveolae, represents a scaffolding molecule for several signaling proteins including EGFR. Although caveolin-1 has been shown to play a role in inducing the invasive phenotype of cancer cells, its role appears to be cell-type specific and for some tumors it has not been defined yet. In this study we used 57 HNSCC specimens to investigate whether the abnormal expression of caveolin-1 was associated with the derangement of the E-cadherin-catenins complex and with the overexpression of ErbB receptors. We demonstrate that in HNSCCs caveolin-1 overexpression is associated with the simultaneous abnormal expression of at least one member of the E-cadherin/α-β catenins complex and multiple ErbB receptors as well as with lymph node metastases. We also demonstrate that chronic stimulation of a human hypopharyngeal carcinoma cell line (FaDu) with EGF induced the internalization of β-catenin and caveolin-1 and their co-localization with EGFR. Moreover, EGF treatment induced an increased physical interaction between EGFR/β-catenin/caveolin-1 and between E-cadherin/β-catenin/caveolin-1. These molecular events were associated with an increased directional motility of FaDu cells in vitro. These findings may provide new insight into the biology of HNSCC progression and help to identify subgroups of primary HNSCCs with a more aggressive behavior.

Analysis of promoters and expression-targeted gene therapy optimization based on doubling time and transfectability

Genes under the control of the cyclooxygenase-2 (Cox-2), human epidermal growth factor receptor 2 (Her-2), and survivin promoters were constructed and delivered to murine and human carcinoma cells. It was found that (P)Cox-2-driven reporter expression was strong and correlated well with endogenous Cox-2 levels, while (P)Her-2 and (P)survivin yielded poor results, consistent with the three distinct expression mechanisms used by cancer cells to overexpress the endogenous versions of the selected genes. The (P)Cox-2 was then used to drive the expression of caspase genes both in vitro and in vivo to bring about targeted apoptosis of carcinoma cells successfully. The results led to the following conclusions. 1) When selecting a promoter/enhancer for expression-targeted gene delivery, it is not enough to perform a microarray on some tumor tissue and select the control element associated with the greatest amount of gene up-regulation vs. normal controls. The mechanism of expression for the particular gene should be taken into account to prevent lengthy and costly research trials. 2) When overexpression is due to activator binding, a predictive model based on endogenous gene expression levels, overall cell transfectability, and cell doubling rates can be used to predict expression-targeted gene delivery outcomes with significant accuracy.