Role of cytoplasmic localization of maspin in promoting cell invasion in breast cancer with aggressive phenotype

Exploring the molecular mechanisms network of breast cancer by multi-omics analysis

BACKGROUND

Breast cancer (BC), the most prevalent malignancy in women globally, still lacks comprehensive research on its molecular targets and necessitates further investigation into the underlying molecular mechanisms driving its initiation and progression.

METHODS

The GSE20685 Series Matrix File downloaded from the Gene Expression Omnibus database was divided into a high-risk group (n = 49) and a low-risk group (n = 278) to construct the co-expression network.

RESULTS

Four hub genes were identified based on the Weighted Gene Co-expression Network Analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analyses were performed. Hub gene immune infiltration was investigated using the Tumor Immune Estimation Resource database, and CD4+ T cell expression levels were substantially correlated with hub gene expression. Based on the CancerRxGene database (Genomics of Drug Sensitivity in Cancer database), it was found that the hub genes were highly sensitive to common chemotherapy drugs such as AKT inhibitor VIII and Erlotinib. The expression of Secreted Frizzled-Related Protein 1, melanoma-inhibiting activity (MIA), and Keratin 14 was related to tumor mutation burden, and the expression of MIA also affected the microsatellite instability of the tumor. This study employs multi-omics analysis to investigate the molecular network associated with the prognosis of BC, highlighting its intricate connection with the immune microenvironment.

CONCLUSION

These findings pinpoint four crucial genes in BC progression, offering targets for further research and therapy. Their connections to immune infiltration and chemotherapy sensitivity underscore complex interactions in the tumor microenvironment.

The Role of Galectin3, Tubulinβ, and Maspin in Promoting Tumor Budding in Colorectal Carcinoma and Their Clinical Implications

Colorectal cancer (CRC) is a leading cause of death worldwide. Despite the advances in surgical and therapeutic management, tumor metastases and poor prognosis are still major problems. Tumor budding is a relevant prognostic factor in CRC, and it can predict tumor metastasis. Galectin3 is responsible for the development and progression of many cancers through the regulation of cell-cell/cell-matrix interactions and tumor cell invasion. Tubulin is a microtubule protein, and maspin is a serine protease inhibitor; both induce tumor cell invasion through the stimulation of epithelial-mesenchymal transition. This study aims to evaluate the relationship between the expression of galecin3, tubulinβ, and maspin in CRC and clinicopathological features, including tumor budding, their prognostic roles, and clinical implications using immunohistochemistry. Galectin3, tubulinβ, and maspin were detected in tumor cells in 95%, 65%, and 87.5% of cases and in stromal cells in 28.8%, 40%, and 0% of cases. High expression of galectin3 and tubulinβ expression either in tumor cells or stroma was significantly associated with aggressive tumor features such as lymph node metastasis, lymphovascular invasion, tumor budding, and advanced tumor stage. The nucleocytoplasmic expression of maspin in tumor cells showed a significant association with deeper tumor invasion, lymph node metastasis, tumor budding, and advanced tumor stage. Significant associations were found between high galectin3 tumor cell expression and nucleocytoplasmic maspin and shorter survival. High expression of galectin3, tubulinβ, and nucleocytoplasmic maspin were significantly associated with aggressive tumor features such as tumor invasion, metastasis, high tumor budding, and short survival in CRC. They could be used as biomarkers for tumor budding and tumor aggressiveness in CRC and may be considered for future target therapy.

P176S Mutation Rewires Electrostatic Interactions That Alter Maspin Functionality

Maspin is known to regress tumors by inhibiting angiogenesis; however, its roles have been reported to be context- and sequence-dependent. Various proteins and cofactors bind to maspin, possibly explaining its conflicting roles. Moreover, polymorphic forms of maspin have also been linked to tumor regression and survival; for instance, maspin with Ser at 176 (maspin-S176) promotes tumors, while maspin with Pro at 176 (maspin-P176) has opposing roles in cancer pathogenesis. With the help of long molecular dynamics simulations, a possible link between polymorphic forms and tumor progression has been established. First, maspin is dynamically stable with either amino acid at the 176 position. Second, differential contacts have been observed among various regions; third, these contacts have significantly altered the electrostatic energetics of various residues; finally, these altered electrostatics of maspin-S176 and maspin-P176 rewire the polar contacts that abolished the allosteric control of the protein. By combining these factors, the altered electrostatics substantially affect the localization and preference of maspin-binding partners, thus culminating in a different maspin-protein(cofactor)-interaction landscape that may have been manifested in previous conflicting reports. Here, the underlying reason has been highlighted and discussed, which may be helpful for better therapeutic manipulation.

Clinical Significance of Subcellular Localization of Maspin in Breast Carcinoma: An Immunohistochemical Study Using Two Different Antibodies

Background

Maspin is known to be a tumor suppressor protein: however, its prognostic value in patients with breast cancer remains controversial. The key influential factors contributing to this complexity may be the differences in antibodies used, as well as the positive criteria and sample size. To date, no study has investigated the prognostic significance of maspin expression by using two different antibodies in the same cohort. We aimed to clarify whether differences in antibodies could influence on the prognostic value of maspin in breast cancer patients.

Methods

Immunohistochemical analyses using an anti-maspin antibody (clone G167-70) were performed on 164 resected specimens of invasive carcinoma of no special type (NOS). The correlation with clinicopathological factors was compared to previous results using clone EAW24, with longer follow-up duration.

Results

The subcellular localization of maspin expression was as follows: cytoplasmic-only staining, 3 cases (1.8%), pancellular staining, 43 cases (26.2%); and no staining, 118 cases (72.0%). No nuclear-only staining was observed. There was no significant correlation between clinicopathological characteristics and the pancellualr expression of maspin. The pancellular expression group showed a significantly longer disease-free survival (DFS) than the other groups (P = 0.046). When clone EAW24 was used, the cytoplasmic-only staining group showed significantly shorter DFS than the pancellular staining group (P = 0.003).

Conclusion

Clone EAW24 may be superior to clone G167-70 in selecting breast carcinoma with an aggressive phenotype, while clone G167-70 may be superior to clone EAW24 in selecting non-aggressive breast carcinoma.

Integrating the tumor-suppressive activity of Maspin with p53 in retuning the epithelial homeostasis: A working hypothesis and applicable prospects

Epithelial malignant transformation and tumorous development were believed to be closely associated with the loss of its microenvironment integrity and homeostasis. The tumor-suppressive molecules Maspin and p53 were demonstrated to play a crucial role in body epithelial and immune homeostasis. Downregulation of Maspin and mutation of p53 were frequently associated with malignant transformation and poor prognosis in various human cancers. In this review, we focused on summarizing the progress of the molecular network of Maspin in studying epithelial tumorous development and its response to clinic treatment and try to clarify the underlying antitumor mechanism. Notably, Maspin expression was reported to be transcriptionally activated by p53, and the transcriptional activity of p53 was demonstrated to be enhanced by its acetylation through inhibition of HDAC1. As an endogenous inhibitor of HDAC1, Maspin possibly potentiates the transcriptional activity of p53 by acetylating the p53 protein. Hereby, it could form a “self-propelling” antitumor mechanism. Thus, we summarized that, upon stimulation of cellular stress and by integrating with p53, the aroused Maspin played the epigenetic surveillant role to prevent the epithelial digressional process and retune the epithelial homeostasis, which is involved in activating host immune surveillance, regulating the inflammatory factors, and fine-tuning its associated cell signaling pathways. Consequentially, in a normal physiological condition, activation of the above “self-propelling” antitumor mechanism of Maspin and p53 could reduce cellular stress (e.g., chronic infection/inflammation, oxidative stress, transformation) effectively and achieve cancer prevention. Meanwhile, designing a strategy of mimicking Maspin’s epigenetic regulation activity with integrating p53 tumor-suppressive activity could enhance the chemotherapy efficacy theoretically in a pathological condition of cancer.