Tumor growth manifested in two-fifths of low-risk papillary thyroid microcarcinoma patients during active surveillance: data from a tertiary center in China.

Purpose: To assess tumor growth using tumor doubling rate (TDR) during active surveillance (AS) in China. Methods: Between January 2016 and June 2020, a total of 219 patients with low-risk papillary thyroid microcarcinoma (PTMC) (aged 23-75 years) were consecutively enrolled in the AS program. Results: Four sections of TDR, >0.5, 0.1~0.5, -0.1~0.1 and <-0.1, corresponded with four categories of tumor volume kinetics: rapid growth, slow growth, stable, and decreased size. We found that 10.5% of PTMCs exhibited rapid growth, 33.33% exhibited slow growth, 26.48% were stable, and 29.68% decreased in size. Tumor growth was associated with two factors: age and volume of PTMC at diagnosis. 85.72% of elderly patients (≥ 61 years old) had tumors that remained stable or even shrank and rapidly growing tumors were not found in them. When the volume was small (≤14.13 mm3), the proportion of rapid growth was high (41.67%), whereas when the volume was large (> 179.5 mm3), the proportion of non-growth was 68.75%. Conclusion: TDR may be a better metric for evaluating tumor growth in observational PTMCs. A certain proportion of PTMCs grow during the period of AS and tumor growth was associated with age and volume of PTMC at initial diagnosis. Therefore, how to block tumor growth during the AS period, especially for young patients and patients with early-stage PTMC (size ≤ 5 mm), will be a new challenge.

The safety and efficacy of delayed surgery by simulating clinical progression of observable papillary thyroid microcarcinoma: a retrospective analysis of 524 patients from a single medical center.

Objective: When active surveillance (AS) is developed in the patients with low-risk papillary thyroid microcarcinoma (PTMC), a medical center needs to ensure the delayed operation that is caused by PTMC clinical progression to have the same prognosis as that of immediate operation. The objective of this study was to investigate the efficacy of delayed surgery by simulating clinical progression (tumor size enlargement and appearance of lymph node metastasis) of PTMCs with AS in a single medical center. Methods: We retrospectively analyzed the response to therapy in 317 papillary thyroid carcinoma patients treated with total thyroidectomy and post-operative radioactive iodine ablation. They were classified into three groups according to tumor size (group A ≤0.5 cm; group B >0.5 cm and ≤1 cm; group C >1 cm and ≤1.5 cm) or two groups according to the presence (cN1) or absence (cN0) of the clinical lymph node (LN) metastasis. Groups C and cN1 were regarded as simulated clinical progression of observational PTMC and the operation for them was assumed to be "delayed surgery". However, Groups A, B and cN0 were regarded as no clinical progression and the operation for them was considered as immediate surgery. Results: There were no significantly differences in excellent response to therapy and recurrence-free survival not only among the group A, B and C, but also between the group cN0 and cN1. In other words, these insignificant differences were found between immediate and simulated "delayed" surgeries. Conclusion: For the PTMC patients suitable for AS, the oncological outcomes were also excellent even if surgery was delayed until after the presence of clinical progression, according to our clinical simulation. Furthermore, we consider that it was feasible for medical centers to assess the ability to implement AS for PTMC patients by retrospectively analyzing their own previous clinical data using the described simulation.

MiR-3121-3p promotes tumor invasion and metastasis by suppressing Rap1GAP in papillary thyroid cancer in vitro.

BACKGROUND: Rap1GAP is a tumor suppressor and is downregulated in human malignancies including papillary thyroid cancer (PTC). The mechanism of its suppression in PTC remains unclear. METHODS: Bioinformatic analyses were carried out to evaluate clinical significance and to predict upstream miRNA bindings of Rap1GAP. Three PTC cell lines, TPC-1, B-CPAP, and K1, were employed for functional verification and further experiments. We used dual-luciferase reporter gene assay to confirm the miRNA binding prediction, Western blotting and quantitative polymerase chain reaction (qPCR) to explore miRNA and Rap1GAP regulation, Transwell and wound healing assays to compare cell migration and invasion after protein knockout or overexpression, and Cell Counting Kit-8 (CCK-8) assay to evaluate cell proliferation. RESULTS: Rap1GAP expression was suppressed in thyroid cancer compared to adjacent normal tissues and was a potential diagnostic marker of PTC. Rap1GAP suppression was correlated to younger age, advanced T stage, N stage, extrathyroidal extension, BRAF-like tumors, and higher risk of recurrence. Combined analysis of bioinformatic prediction and dual-luciferase assay revealed binding between miR-3121-3p with 3'UTR of Rap1GAP promoter. MiR-3121-3p promoted cell migration, invasion, and proliferation via inhibiting Rap1GAP and thus upregulating MAPK pathway. Overexpression and knockdown of Rap1GAP could counteract the influence on cell migration and invasion carried out by miR-3121-3p mimic and inhibitor, respectively. Rap1GAP partially impaired the effect of miR-3121-3p in cell growth in the CCK-8 assay. CONCLUSIONS: Rap1GAP expression is suppressed in PTC and is a potential diagnostic marker. Its upstream regulator, miR-3121-3p, affects tumor metastasis and proliferation via regulating Rap1GAP expression. MAPK signaling pathway may be involved in this effect.

M2 macrophage-induced lncRNA PCAT6 facilitates tumorigenesis and angiogenesis of triple-negative breast cancer through modulation of VEGFR2.

As a common female malignancy, triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancers (BC). This study further studied the role of long noncoding RNA (lncRNA) prostate cancer-associated transcript 6 (PCAT6) in TNBC. Functional assays, including EdU, wound healing, transwell, and immunofluorescence staining, revealed the effect of PCAT6 on cell proliferation, migration, and EMT process. The tube-formation assay disclosed the function of PCAT6 on angiogenesis. In vivo assays were also established to explore the impact of PCAT6 on tumor growth and microangiogenesis. The results revealed that PCAT6 boosted TNBC cell proliferation, migration, and angiogenesis both in vitro and in vivo. Then, this study unveiled that M2 macrophage secreted VEGF to stimulate the upregulation of PCAT6, thus promoting angiogenesis in TNBC. Next, through bioinformatics analysis and mechanism assays, we identified that PCAT6 positively regulated VEGFR2 expression via ceRNA pattern and then participated in VEGFR/AKT/mTOR signaling pathway to accelerate angiogenesis. Moreover, PCAT6 bound USP14, a deubiquitinase, to induce the deubiquitination of VEGFR2. On the whole, M2 macrophage-induced upregulation of PCAT6 facilitates TNBC tumorigenesis through modulation of VEGFR2 expression via ceRNA and deubiquitination patterns.

CXCR4 Antagonist AMD3100 Reverses the Resistance to Tamoxifen in Breast Cancer via Inhibiting AKT Phosphorylation.

Endocrine therapy is a systemic therapy and has become the main treatment strategy for patients with estrogen receptor (ER)-positive breast cancer. However, tamoxifen resistance has become an insurmountable clinical challenge, and the underlying mechanisms are still poorly understood. In this study, we explored the roles of CXC chemokine receptor type 4 (CXCR4) in tamoxifen-treated breast cancer and tamoxifen resistance. Based on the Gene Expression Omnibus (GEO) database, high expression of CXCR4 was found to be associated with worse overall survival (hazard ratio [HR] = 4.646, p < 0.001) and cancer-specific survival (HR = 4.480, p < 0.001) in tamoxifen-treated breast cancer. CXCR4 was also positively correlated with the level of AKT phosphorylation and the resistance to tamoxifen in breast cancer. AMD3100 is a CXCR4 antagonist and was found to decrease phosphorylated (p)-AKT levels of tamoxifen-resistant cells. The reversal effect of AMD3100 on tamoxifen resistance was also confirmed in vitro and in vivo. Taken together, our study demonstrated that CXCR4 could be a potential prognostic biomarker for tamoxifen-treated breast cancer, and the combination of AMD3100 with tamoxifen could be a more efficacious therapeutic strategy for the treatment of tamoxifen resistance.

SRC Promotes Tamoxifen Resistance in Breast Cancer via Up-Regulating SIRT1.

BACKGROUND: Endocrine therapy plays a key role in estrogen receptor-positive breast cancer patients; but, tamoxifen resistance could be a real difficulty for these patients. Several attempts have been made to explore the mechanism and new therapies for these patients. We intend to clarify the expression change of SRC and SIRT1 in tamoxifen-resistant breast cancer cells and explore their functions on tamoxifen resistance. METHODS: SRC and SIRT1 expressions were analyzed by RNA sequencing, qPCR and Western blotting. Loss and gain of function of SRC and SIRT1 were utilized to indicate their oncogenic roles in tamoxifen resistance in vitro and in vivo. Kaplan-Meier analysis and receiver operating characteristic curve were used to evaluate the survival and the predicted effects of SRC and SIRT1 on patients' prognosis. RESULTS: High expressions of SRC and/or SIRT1 were found in tamoxifen-resistant cells and related to poor overall survival (p<0.05 for SRC, p<0.001 for SIRT1, p<0.001 for SRC and SIRT1) and cancer-specific survival (p<0.05 for SRC, p<0.01 for SIRT1, p<0.01 for SRC and SIRT1) of tamoxifen-treated breast cancer patients. Down-regulation of SRC (p<0.01) or SIRT1 (p<0.05) separately reversed the resistance to tamoxifen and the minimal concentration of SRC inhibitor KX-01 (p<0.05) or SIRT1 inhibitor EX527 (p<0.001) could also suppress cell proliferation. The expression level of SIRT1 was positively correlated with that of SRC. Overexpression of SRC significantly promotes the cell resistance to tamoxifen inhibited by SIRT1 (p<0.01). In vivo experiments confirmed the effects of SRC on tumor growth by over- or down-regulating SRC expression (p<0.001 and p<0.001, respectively). CONCLUSION: SRC and SIRT1 are both up-regulated in tamoxifen-resistant breast cancer cells and related to a poor prognosis in tamoxifen-treated breast cancer. Moreover, SRC could promote tamoxifen resistance by up-regulating SIRT1. SRC and SIRT1 might be novel therapeutic targets in tamoxifen-resistant breast cancer and the interaction between SRC and SIRT1 needs to be further explored.

Immune and Stroma Related Genes in Breast Cancer: A Comprehensive Analysis of Tumor Microenvironment Based on the Cancer Genome Atlas (TCGA) Database.

Background: Tumor microenvironment is essential for breast cancer progression and metastasis. Our study sets out to examine the genes affecting stromal and immune infiltration in breast cancer progression and prognosis. Materials and Methods: This work provides an approach for quantifying stromal and immune scores by using ESTIMATE algorithm based on gene expression matrix of breast cancer patients in TCGA database. We found differentially expressed genes (DEGs) through limma R package. Functional enrichments were accessed through Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Besides, we constructed a protein-protein network, identified several hub genes in Cytoscape, and discovered functionally similar genes in GeneMANIA. Hub genes were validated with prognostic data by Kaplan-Meier analysis both in The Cancer Genome Atlas (TCGA) database and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) database and a meta-analysis of hub genes prognosis data was utilized in multiple databases. Furthermore, their relationship with infiltrating immune cells was evaluated by Tumor IMmune Estimation Resource (TIMER) web tool. Cox regression was utilized for overall survival (OS) and recurrence-free survival (RFS) in TCGA database and OS in METABRIC database in order to evaluate the impact of stromal and immune scores on patients prognosis. Results: One thousand and eighty-five breast cancer patients were investigated and 480 differentiated expressed genes (DEGs) were found based on the analysis of mRNA expression profiles. Functional analysis of DEGs revealed their potential functions in immune response and extracellular interaction. Protein-protein interaction network gave evidence of 10 hub genes. Some of the hub genes could be used as predictive markers for patients prognosis. In this study, we found that tumor purity and specific immune cells infiltration varied in response to hub genes expression. The multivariate cox regression highlighted the fact that immune score played a detrimental role in overall survival (HR = 0.45, 95% CI: 0.27-0.74, p = 0.002) and recurrence-free survival (HR = 0.41, 95% CI: 0.22-0.77, p = 0.006) in TCGA database. These result was confirmed in METABRIC database that immune score was a protector of OS (HR = 0.88, 95% CI: 0.77-0.99, p = 0.039). Conclusions: Our findings promote a better understanding of the potential genes behind the regulation of tumor microenvironment and cells infiltration. Immune score should be considered as a prognostic factor for patients' survival.

Comprehensive analysis of the association between tumor glycolysis and immune/inflammation function in breast cancer.

BACKGROUND: Metabolic reprogramming, immune evasion and tumor-promoting inflammation are three hallmarks of cancer that provide new perspectives for understanding the biology of cancer. We aimed to figure out the relationship of tumor glycolysis and immune/inflammation function in the context of breast cancer, which is significant for deeper understanding of the biology, treatment and prognosis of breast cancer. METHODS: Using mRNA transcriptome data, tumor-infiltrating lymphocytes (TILs) maps based on digitized H&E-stained images and clinical information of breast cancer from The Cancer Genome Atlas projects (TCGA), we explored the expression and prognostic implications of glycolysis-related genes, as well as the enrichment scores and dual role of different immune/inflammation cells in the tumor microenvironment. The relationship between glycolysis activity and immune/inflammation function was studied by using the differential genes expression analysis, gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, gene set enrichment analyses (GSEA) and correlation analysis. RESULTS: Most glycolysis-related genes had higher expression in breast cancer compared to normal tissue. Higher phosphoglycerate kinase 1 (PGK1) expression was associated with poor prognosis. High glycolysis group had upregulated immune/inflammation-related genes expression, upregulated immune/inflammation pathways especially IL-17 signaling pathway, higher enrichment of multiple immune/inflammation cells such as Th2 cells and macrophages. However, high glycolysis group was associated with lower infiltration of tumor-killing immune cells such as NKT cells and higher immune checkpoints expression such as PD-L1, CTLA4, FOXP3 and IDO1. CONCLUSIONS: In conclusion, the enhanced glycolysis activity of breast cancer was associated with pro-tumor immunity. The interaction between tumor glycolysis and immune/inflammation function may be mediated through IL-17 signaling pathway.

The potential of Diosgenin in treating psoriasis: Studies from HaCaT keratinocytes and imiquimod-induced murine model.

AIMS: Psoriasis is a cutaneous disease mainly characterized by keratinocyte hyperproliferation, abnormal epidermal differentiation, inflammation and angiogenesis. In this study, we aimed to report the therapeutic potential of Diosgenin on psoriasis-like models and explore the underlying mechanisms. MAIN METHODS: For in vitro studies, we initially evaluated the bioeffects of Diosgenin on keratinocytes by detecting the cell viability, cell cycle and apoptosis in HaCaT cells. To mimic psoriatic conditions, we established hyperproliferative model by stimulating HaCaT cells with LPS/IL-22 and inflammatory model by LPS/TNF-α stimulation. Meanwhile, differentiation in HaCaT cells and angiogenesis in HUVECs/HMEC-1 were observed. The influence of Diosgenin on above-mentioned conditions was examined. For in vivo studies, we dosed imiquimod (IMQ) -induced mice with Diosgenin and conducted hematoxylin-eosin (HE), TUNEL assay and immunohistochemistry (IHC) to evaluate histological changes, apoptosis and the status of keratinocyte proliferation, epidermal differentiation, vascularity and cutaneous inflammatory cell infiltration respectively. KEY FINDINGS: Results showed that Diosgenin inhibited HaCaT cell growth through cell cycle arrest and NFκB inhibition while induced apoptosis by regulating Caspase3, Bax and Bcl-2 protein expression. After Diosgenin treatment, NFκB nuclear translocation and IL-22 receptor dependent pathways were suppressed in LPS/IL-22 induced HaCaT cells respectively. Furthermore, Diosgenin downregulated proinflammatory cytokines through TLR4/Myd88 inhibition and upregulated several differentiation markers' expression in HaCaT cells. Additionally, Diosgenin inhibited vascular formation partially by reducing the VEGF-α expression in keratinocytes. In animal studies, Diosgenin attenuated psoriatic lesions on mice accordingly. SIGNIFICANCE: This study suggests that Diosgenin might be a promising candidate for developing anti-psoriatic agents.

Gene and lncRNA co-expression network analysis reveals novel ceRNA network for triple-negative breast cancer.

Breast cancer is the most frequently diagnosed malignancy among women, and triple-negative breast cancer (TNBC) is a highly aggressive subtype. Increasing evidence has shown that lncRNAs are involved in tumor growth, cell-cycle, and apoptosis through interactions with miRNAs or mRNAs. However, there is still limited data on ceRNAs involved in the molecular mechanisms underlying TNBC. In this study, we applied the weighted gene co-expression network analysis to the existing microarray mRNA and lncRNA expression data obtained from the breast tissues of TNBC patients to find the hub genes and lncRNAs involved in TNBC. Functional enrichment was performed on the module that correlated with Ki-67 status the most (Turquoise module). The hub genes in the Turquoise module were found to be associated with DNA repair, cell proliferation, and the p53 signaling pathway. We performed co-expression analysis of the protein-coding and lncRNA hub genes in the Turquoise module. Analysis of the RNA-seq data obtained from The Cancer Genome Atlas database revealed that the protein-coding genes and lncRNAs that were co-expressed were also differentially expressed in the TNBC tissues compared with the normal mammary tissues. On the basis of establishing the ceRNA network, two mRNAs (RAD51AP1 and TYMS) were found to be correlated with overall survival in TNBC. These results suggest that TNBC-specific mRNA and lncRNAs may participate in a complex ceRNA network, which represents a potential therapeutic target for the treatment of TNBC.

Combined MEK inhibition and tumor-associated macrophages depletion suppresses tumor growth in a triple-negative breast cancer mouse model.

Tumor-associated macrophages (TAMs) are closely related to poor prognosis in triple-negative breast cancer (TNBC). Thus, gaining insight into how TAMs support cancer progression could contribute to effective therapies. We utilized the 4 T1 murine TNBC cell line and murine bone marrow-derived macrophages to assess TAM-mediated pro-proliferative effects in vivo and in vitro. Further, Transcriptional analysis was performed to identify pathways activated in TAM-stimulated 4 T1 cells. We also explored the therapeutic efficacy of combining a mitogen-activated protein kinase kinase (MEK) inhibitor with TAM-targeted therapy using a TNBC mouse model. We found that the presence of TAMs was significantly associated with proliferating cancer cells in a TNBC mouse model. Moreover, RNA sequencing analysis showed that TAMs could enhance mitogen-activated protein kinase (MAPK) pathway activation in 4 T1 cells compared to that in control cells. Further, the depletion of TAMs by clodronate liposomes significantly reduced MAPK pathway activation in vivo. In addition, the blockade of MAPK signaling by a MEK inhibitor repressed TAM-mediated cancer cell proliferation. Most importantly, MEK inhibition combined with macrophage depletion significantly suppressed tumor growth and increased T lymphocyte infiltration in a TNBC model. Our study suggests the possibility that TAM-induced MAPK pathway activation promotes cancer cell proliferation. Thus, MEK inhibition combined with macrophage depletion might represent an effective treatment for TNBC.