Global cancer statistics show that breast cancer has become the most common cancer among women[17].With the progress of modern diagnosis and treatment technology, although the survival rate of breast cancer has improved, the psychological distress and mental health of patients are still ignored. Depression and anxiety are associated with a significant increase in the incidence rate of cancer. Depression and anxiety may have etiological and prognostic effects on cancer[18].Some studies have shown that breast cancer patients have a high risk of depression, anxiety and other mental diseases[19].According to the systematic review and meta-analysis conducted by Akbar Javan Biparva et al., the global prevalence of depression among women with breast cancer is 30.2%. In addition, with the growth of age, women suffering from breast cancer have an increased risk of depression. Compared with developed regions, the prevalence of depression in breast cancer patients in developing countries is higher[20].Depression is closely related to breast cancer patients' physical defects, disease severity and chronic pain. In addition, if breast cancer and depression occur at the same time, patients will experience more severe pain, extreme fatigue, decreased survival rate and quality of life[21].In a recent meta-analysis, the results confirmed that cancer patients with depressive symptoms have a 25% higher mortality rate, and psychological intervention can effectively improve the 12 month survival rate[22].That is to say, even if cancer patients receive effective anti-tumor treatment, psychological factors such as depression and anxiety still lead to poor prognosis and decreased living standards. Severe depression is common in cancer outpatient patients and most of them do not receive treatment. There is an urgent need to improve the treatment of severe depression in patients receiving professional cancer treatment[23].
With the rise of precision medicine in cancer, more and more research is exploring the relationship between genes and cancer symptoms. Emerging evidence suggests that genetic variations may also be associated with susceptibility to depressive symptoms. The more likely depressive symptoms of breast cancer patients can be identified through biomarker detection, which may lead to higher compliance of patients with treatment, and more proactive detection of depression for patients with genetic risk. This study is based on this as a starting point. Through the analysis of the relationship between breast cancer and depression, we can find the key genes of the two diseases, explore the impact of key genes on the occurrence, progress and treatment of these two diseases, and find biomarkers to predict these two diseases. In this study, CCNB1, MLPH, PSME1 and RACGAP1 were screened from the TCGA database and the NCBI GEO public database as key genes for the comorbidity of breast cancer and depression.
In recent years, with the rapid development of immunotherapy, the research on immune invasion of breast cancer has gradually attracted extensive attention. There are significant differences between breast cancer with different subtypes and pathological characteristics[24].The immune microenvironment is mainly composed of immune cells, extracellular matrix, various growth factors, inflammatory factors, and special physicochemical characteristics, which significantly affect the diagnosis and clinical treatment sensitivity of tumors. The key immune cell subsets in the tumor microenvironment of breast cancer: CD4+Th1 cells produce interferon γ Mediate the expansion, differentiation, and activation of CD8+tumor infiltrating lymphocytes (TIL); CD4+FOXP3+TIL represents immunosuppressive mediators by inhibiting CD8+T cells, CD4+Th1 cells, APCs, and natural killer cells (NKs); M2 TAMs help activate Th2 immune response, thereby exhibiting immunosuppressive effects (such as inhibiting T cell function); NKs are cytotoxic members of the innate immune system (releasing cytotoxic cytokines and directly killing cancer cells); Dendritic cells (DCs) are antigen-presenting cells and play a key role in the adaptive immune system; Myeloid derived inhibitory cells (MDSCs) represent immature myeloid cells (possibly originating from bone marrow precursor cells) that exhibit immunosuppressive function by inhibiting T cells, B cells, NKs, M1-TAMs, and DCs.The recruitment and accumulation of immunosuppressive mediators are caused by the secretion of cytokines and chemokines by tumor cells, such as IL-6 and IL-1- β、 Transforming Growth Factor-1 β、 CCl_ 2) Mediated[25].Chronic stress can affect immune function and promote tumor growth by reducing T cell-mediated immunity and reducing lymphocyte count[26].By analyzing the relationship between key genes and immune invasion, we further explore the potential molecular mechanism of key genes affecting the progress of breast cancer. This study suggests a correlation between the distribution of immune infiltration levels of these four key genes and immune cells. Compared with normal patients, the contents of T cells follicular helper, T cells regulatory (Tregs), Macrophages M0, and Macrophages M1 in breast cancer patients were significantly higher, and there was a strong correlation with immune cells. The results were in line with expectations.
Chronic stress can weaken NK cell function and inhibit its activity, induce changes in macrophage phenotype from M1 to M2, and promote tumor progression. Chronic psychological stress can increase the mobilization of MDSC (bone marrow-derived suppressive cells, immature myeloid cells with effective immunosuppressive activity), leading to tumor infiltration in TAMs, and the stress hormone NE is activated through β 2-AR promotes the release of neuropeptide Y (NPY) in prostate cancer cells, thereby activating the IL6-STAT3 signaling pathway and promoting tumor growth[27-29].In addition, the lymphatic system plays an important role in immune function and also contributes to the invasion and metastasis of tumor cells. Research has found that chronic stress can promote the spread of tumor cells by reshaping the lymphatic system[30].In addition, genetic polymorphisms in inflammatory genes such as interleukin-1 (IL-1) β (IL-1b), IL-6, IL-10, monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor α TNFA, C-reactive protein (CRP), and phospholipase A2 (PLA2) are known to contribute to depression and immune activation. BDNF and some inflammatory genes are considered as strong biomarkers of depression susceptibility in breast cancer. In Chinese patients with early breast cancer, the variation of IL-10, IFNG1 and BDNF is associated with anxiety/depression symptoms[31].This study suggests that the expression levels of CCNB1, MLPH, PSME1 and RACGAP1, four key genes, are significantly correlated with the expression levels of breast cancer progression genes. RACGAP1 and BRIP1 are significantly positively correlated (r=0.688), and MLPH and MSH2 are significantly negatively correlated (r=-0.404).The higher number of anti-inflammatory cytokine risk alleles, as well as the IL-1P-511T/T genotype, are associated with baseline prevalent depression and one-year follow-up persistent depression, respectively[32].Inflammatory diet is positively related to breast cancer related depression, which may be caused by tumor necrosis factor- α Mediated[33].This study revealed the specific signal pathways of four key genes in breast cancer, and explored the potential molecular mechanism of key genes and breast cancer progression.GSVA analysis of breast cancer showed that overexpression of CCNB1 could enrich E2F_ TARGETS, DNA_ REPAIR and other signaling pathways, high expression of MLPH can enrich P53_ PATHWAY, PI3K_ AKT_ MTOR_ Signaling and other signaling pathways; PSME1 can enrich FATTY_ ACID_ METABOLISM, DNA_ REPAIR and other signaling pathways; RACGAP1 can enrich E2F_ TARGETS, G2M_ Signal pathways such as CHECKPOINT.GSEA analysis of breast cancer showed that CCNB1 was mainly enriched in DNA replication, Fanconi anemia pathway, mRNA surveillance pathway and other signaling pathways; MLPH is mainly enriched in signal pathways such as Chemokine signaling pathway, IL-17 signaling pathway, and TNF signaling pathway; PSME1 is mainly enriched in signaling pathways such as Cytosolid DNA sensing pathway, Neoptosis, RIG-I-like receiver signaling pathway, etc,; RACGAP1 is mainly enriched in signaling pathways such as Carbon metabolism, mRNA surveillance pathway, and Pyrimidine metabolism; These four key genes may affect the progress of breast cancer through these pathways.
The transcriptional regulation analysis of four key genes in this study showed that the Motif motif with the highest standardized enrichment score (NES: 8.74) was cisbp__ M5204. We have demonstrated all enriched motifs and corresponding transcription factors of key genes. They were found to be regulated by common mechanisms such as multiple transcription factors.Si T et al. have pointed out that overexpression of CCNB1 implies potential cell cycle disruption. The higher the expression, the faster the proliferation of abnormal cells, and the greater the likelihood of tumor development[34].CCNB1 is overexpressed in TNBC and hormone receptor positive breast cancer, and overexpression is closely related to the low survival rate and poor prognosis of breast cancer patients[35-37].Studies have shown that high expression of CCNB1 mRNA is associated with aggressive behavior of breast cancer, which can promote tumor progression by promoting lymphatic invasion[38].However, the mechanism of CCNB1 promoting the progression of breast cancer is still unclear. It has been reported that an increase in the expression level of CCNB1 can regulate the activation of mitogen activated protein kinase 7 (MAPK7) in G2/M phase, thereby regulating mitosis[39].Our results indicate that CCNB1 is mainly enriched in MAPK signaling pathway, which suggests that CCNB1 may regulate cell cycle through MAPK signaling pathway to promote the progress of breast cancer. RACGAP is a RacGTP enzyme activating protein involved in cell growth regulation, cell transformation, and metastasis. The increased expression of RACGAP1 in most cancers suggests poor prognosis, which may be related to its involvement in various cancer related pathways such as cell cycle, methylation levels, immune cell infiltration, and response to immunotherapy, as well as chemical resistance. RACGAP1 can inhibit anti-tumor immunity and immunotherapy responses by promoting immune cell infiltration and cytotoxic T lymphocyte dysfunction.The Gene Expression Omnibus database shows that increased expression of RACGAP1 is associated with shortened PFS in nasopharyngeal carcinoma patients. RACGAP1 may affect cell cycle progression, DNA replication, metabolism, and immune related pathways, leading to recurrence and metastasis of nasopharyngeal carcinoma. This study suggests that RACGAP1 may become a potential biomarker for pan cancer and nasopharyngeal carcinoma[40].Research shows that RACGAP1 is overexpressed in breast cancer cells. High expression of RACGAP1mRNA has been found to have adverse prognostic significance in breast cancer[41].Ren K et al found that RACGAP1 can promote breast cancer metastasis by regulating mitochondrial quality control. RACGAP1 promotes mitochondrial autophagy and mitochondrial biosynthesis by regulating DRP1 phosphorylation and PGC-1a expression, and ultimately improves mitochondrial quality control in breast cancer cells[42].Zhou D et al. also found that the promotion of lncRNA RACGAP1P on mitochondrial fission depends on its competitive binding with miR-345-5p and its parent gene RACGAP1, which leads to the activation of dynamic related protein 1 (Drp1), mediating mitochondrial fission and promoting the invasion and metastasis of breast cancer[43].PSME1 can serve as an iron death immune related gene for risk stratification in patients with invasive ductal carcinoma of the breast (IDC). This model helps to evaluate the prognosis of patients and guide individualized treatment, and further elucidates the molecular mechanism of IDC[44].Melanin protein MLPH has been widely reported in prostate cancer, and MLPH can promote tumor progression by accelerating the epithelial mesenchymal transition of prostate cancer[45].In breast cancer, androgen receptor (AR) has gradually attracted people's attention. Some studies have shown that AR and MLPH have the same expression, and MLPH can play different roles in different subtypes of breast cancer[46].At present, the research of key genes in breast cancer remains to be explored.
There are few reports on CCNB1, PSME1, MLPH, and RACGAP1 in depression. The pathways involved, such as cGMP PKG signaling pathway, MAPK signaling pathway, PI3K Akt signaling pathway, and Ras signaling pathway, are closely related to depression.Our results indicate that RACGAP1 and FKBP5 (depression regulatory genes) are significantly positively correlated (r=0.625), while PSME1 and SLC6A4 (depression regulatory genes) are significantly negatively correlated (r=− 0.706) (Fig3.2). The PI3K/Akt/mTOR pathway plays a crucial role in cancer cell growth, proliferation, and angiogenesis, and also plays an important role in the pathophysiology of brain homeostasis and emotional disorders.Depression may affect susceptibility to cancer, but the genes and signaling pathways that mediate this association are still unclear[47].The PI3K/Akt/mTOR inhibitor everolimus can cause significant emotional changes in breast cancer patients[48].The mechanism of ATAS acupuncture in reducing fatigue and depression may be related to ADROA1 regulating the cGMP/PKG pathway[49].The high conservatism of the NO/cGMP/PKG signaling pathway suggests that it may be involved in regulating neural diffusion inhibition SD in other organisms, including mammals[50].Inhibiting NCALD and spiral administration can alleviate depressive behavior by regulating the expression of apoptotic cytokines and sGC/cGMP/PKG signaling pathways. Overexpression of NCALD reversed the improvement effect of silent NCALD and spiral administration[51].This study analyzed the potential molecular mechanisms of four key genes affecting the progression of depression. The results of GSVA analysis of depression showed that high expression of CCNB1 enriched E2F_ TARGETS, PROTEIN_ SECRETION and other signal pathways; High expression of MLPH can enrich G2M_ CHECKPOINT, MYC_ TARGETS_ Signal pathways such as V1; PSME1 can enrich E2F_ TARGETS, UV_ RESPONSE_ UP and other signaling pathways; RACGAP1 can enrich TGF_ BETA_ Signaling and other signaling pathways.The GSEA analysis of depression shows that CCNB1 is mainly enriched in signal pathways such as cGMP PKG signaling pathway, MAPK signaling pathway, and Notch signaling pathway; MLPH is mainly enriched in signal pathways such as B cell receiver signaling pathway, cGMP PKG signaling pathway, PI3K Akt signaling pathway, etc; PSME1 is mainly enriched in signal pathways such as Rap1 signaling pathway, Calcium signaling pathway, PI3K Akt signaling pathway, etc; RACGAP1 is mainly enriched in signaling pathways such as Ras signaling pathway, Calcium signaling pathway, and PI3K Akt signaling pathway.The pathogenesis of depression, especially its comorbidity with cancer, has always been a focus of research. For example, changes in p38 MAPK expression in esophageal cancer patients are associated with poor prognosis, and p38 may be a potential biomarker for predicting depression symptoms and prognosis in esophageal cancer patients[52].Paroxetine induces apoptosis of human breast cancer MCF-7 cells through the production of extracellular Ca2+and p38 MAPK dependent ROS. The results show that Paroxetine can be used as an anticancer adjuvant in current cancer treatment, and can be used to treat breast cancer patients with or without depression[53].Wefers B et al. revealed the differential function of MAPK signaling in the life stages of adolescents and adults, and emphasized that early post birth is crucial for determining anxiety, enabling it to distinguish between the genetic functions of the adult and developing postpartum brain in adults[54].The ROS/p38 MAPK/NLRP3 inflammatory cascade reaction is associated with arsenic induced depression/anxiety. In addition, NAC may become a potential therapeutic agent for arsenic induced depression/anxiety by inhibiting ROS production and ROS induced NLRP3 inflammasome activation[55].The activation of p38 MAPK signaling pathway induced by adrenaline enhances the malignancy of breast cancer in depression[56].BrewerJ K et al. demonstrated that the Notch signaling pathway is involved in depression. Increased Notch2/NF- κ B in the medial prefrontal cortex ,the signal transduction may mediate susceptibility to depression and provide potential diagnostic biomarkers or therapeutic targets for the treatment of severe depression[57].The imbalance of ras oncogenes can lead to impaired synthesis of serotonin and dopamine, manifested as severe depression. The higher the correlation between cancer types and the Ras oncogene family, the greater the correlation between depression and the onset of advanced cancer[58].
The four key genes in this study are closely related to the occurrence and development of breast cancer and depression, but their correlation with drug treatment of these two diseases needs further exploration, especially the sensitivity of anti-tumor drugs for breast cancer. This study analyzed that CCNB1 is significantly related to the sensitivity of AKT.inhibitor.VIII, Cisplatin, Dasatinib, Erlotinib, Gefitinib.Ding K et al. conducted gene set enrichment analysis (GSEA), and the expression of CCNB1 was positively correlated with overexpression of genes in endocrine therapy resistant samples. The interaction between CCNB1 and several available anticancer drugs was demonstrated using the CCNB1 Drug interaction network. It is suggested that CCNB1 is a biomarker for monitoring the prognosis of ER+breast cancer and the efficacy of hormone therapy, which is also a promising goal for developing new strategies to prevent or even reverse drug resistance to hormone therapy[59].Kongsema et al. pointed out that thiostreptomycin treatment reduced the mRNA expression of cyclin B1 (CCNB1), which is a downstream target of FOXM1. This indicates that thiostreptosin can inhibit the expression of FOXM1 mRNA, and has a certain inhibitory effect on CCNB1, thus indicating that thiostreptosin is a specific and direct inhibitor of FOXM1 protein in breast cancer, which may lead to the development of new treatment strategies for breast cancer, and help to overcome resistance to conventional chemotherapy drugs[60].In addition, studies have suggested that the epigenetic markers of the nuclear target pY88-H4 of activated ACK1 are deposited on the cell cycle genes CCNB1, CCNB2, and CDC20, which in turn initiate their effective transcription. Pharmacological inhibition of ACK1 using its inhibitor (R) -9b will inhibit the expression of CCNB1, CCNB2, and CDC20, leading to G2/M phase arrest and ultimately leading to the growth regression of breast tumors resistant to palbociclib. In addition, (R) -9b inhibited the expression of CXCR4 receptor, which led to limited metastasis of breast cancer cells to the lung. It suggests that the activated ACK1 is recognized as an oncogene, which controls the cell cycle gene of G2/M conversion in breast cancer cells in epigenetics, thus suggesting that the inhibitor of ACK1 (R) -9b may be a new treatment option for breast cancer patients who are resistant to CDK4/6 inhibitors[61].At present, there are few reports on the drug sensitivity of the other three key genes in this study, but the correlation analysis of their anti-tumor drug sensitivity suggests that MLPH is significantly correlated with the sensitivity of AKT.inhibitor.VIII, Cisplatin, Dasatinib, Erlotinib, Gefitinib, and Gemcitabine; PSME1 is significantly correlated with the sensitivity of Cisplatin and Dasatinib; RACGAP1 is significantly correlated with the sensitivity of Cisplatin, Dasatinib, and Erlotinib, providing a reference for the sensitivity selection of anti-tumor drugs. The correlation between these four key genes in the drug treatment of depression requires further specific analysis and research.We not only need to study the occurrence, development and interaction of breast cancer and depression, but also analyze the prognosis of these two diseases, especially breast cancer. ZhuX L et al. obtained a C-index of 0.803 and a reliable calibration curve in the evaluation of the Nomogram model. The Nomogram model proposed provides a feasible tool for accurate prognosis prediction, which can serve as a personalized diagnostic tool to evaluate prognosis and help propose treatment plans for MBC patients[62].Ma X et al. identified several independent prognostic factors and constructed a Nomogram to predict OS and CSS in MBC patients of childbearing age. These prognostic models should be considered in clinical practice to provide personalized treatment for this group of patients[63].This study shows them through regression analysis results through key gene expression and clinical information and in the form of nomogram. The values of different clinical indicators of breast cancer and the expression distribution of key genes have different contributions in the whole scoring process. At the same time, this study also conducted predictive analysis on the OS situation over three and five years, and the results showed that the predicted OS was in good agreement with the observed OS, indicating that the Nomogram model in this study has good predictive performance. Png K J et al. pointed out that the progression of cancer metastasis is a complex and clinically daunting process.