Foxp3 and Bcl6 deficiency synergistically induces spontaneous development of atopic dermatitis-like skin disease.

Atopic dermatitis (AD) is a common chronic skin disease caused by immune dysfunction, specifically the hyperactivation of Th2 immunity. AD is a complex disease with multiple factors contributing to its development; however, the interaction between these factors is not fully understood. In this study, we demonstrated that the conditional deletion of both the forkhead box p3 (Foxp3) and B-cell lymphoma 6 (Bcl6) genes induced the spontaneous development of AD-like skin inflammation with hyperactivation of type 2 immunity, skin barrier dysfunction, and pruritus, which were not induced by the single deletion of each gene. Furthermore, the development of AD-like skin inflammation was largely dependent on IL-4/13 signaling but not on immunoglobulin E (IgE). Interestingly, we found that the loss of Bcl6 alone increased the expression of thymic stromal lymphopoietin (TSLP) and interleukin (IL)-33 in the skin, suggesting that Bcl6 controls Th2 responses by suppressing TSLP and IL-33 expression in epithelial cells. Our results suggest that Foxp3 and Bcl6 cooperatively suppress the pathogenesis of AD. Furthermore, these results revealed an unexpected role of Bcl6 in suppressing Th2 responses in the skin.

High expression of PKCλ and ALDH1A3 indicates a poor prognosis, and PKCλ is required for the asymmetric cell division of ALDH1A3-positive cancer stem cells in PDAC.

Pancreatic ductal adenocarcinoma (PDAC) is the cancer with the poorest prognosis. One of the major properties reflecting its poor prognosis is high-grade heterogeneity, which leads to insensitivity to anticancer treatments. Cancer stem cells (CSCs) acquire phenotypic heterogeneity, generating abnormally differentiated cells by asymmetric cell division. However, the detailed mechanism leading to phenotypic heterogeneity is largely unknown. Here, we showed that PDAC patients with co-upregulation of PKCλ and ALDH1A3 had the poorest clinical outcome. PKCλ knockdown by DsiRNA in the ALDH1high population of PDAC MIA-PaCa-2 cells attenuated the asymmetric distribution of the ALDH1A3 protein. To monitor asymmetric cell division of ALDH1A3-positive PDAC CSCs, we established stable Panc-1 PDAC clones expressing ALDH1A3-turboGFP (Panc-1-ALDH1A3-turboGFP cells). In addition to MIA-PaCa-2-ALDH1high cells, turboGFPhigh cells sorted from Panc-1-ALDH1A3-turboGFP cells showed asymmetric cell propagation of ALDH1A3 protein. PKCλ DsiRNA in Panc-1-ALDH1A3-turboGFP cells also attenuated the asymmetric distribution of ALDH1A3 protein. These results suggest that PKCλ regulates the asymmetric cell division of ALDH1A3-positive PDAC CSCs. Furthermore, Panc-1-ALDH1A3-turboGFP cells can be useful for the visualization and monitoring of CSC properties such as asymmetric cell division of ALDH1A3-positive PDAC CSCs in time-lapse imaging.

Aberrant Nuclear Localization of aPKCλ/ι is Associated With Poorer Prognosis in Uterine Cervical Cancer.

We previously reported that aberrant expression of atypical protein kinase C λ/ι (aPKCλ/ι) in low-grade squamous intraepithelial uterine cervix lesions was associated with an increased risk of progression to higher grade. This study aimed to investigate aPKCλ/ι expression patterns in cervical squamous cell carcinoma (SCC) and its association with disease progression. We immunohistochemically assessed aPKCλ/ι expression in 168 SCC samples and 13 normal uterine cervix samples. In 69.0% of SCC cases, aPKCλ/ι was expressed more abundantly than in normal epithelium, but there was no significant association between aPKCλ/ι intensity and disease progression (P=0.087, Cochran-Mantel-Haenszel test). aPKCλ/ι in normal cervical epithelium was confined to the cytoplasm or intercellular junctions. In contrast, aPKCλ/ι was predominantly localized within the nucleus in 36.9% of SCC samples (P<0.001, χ test), and the prevalence was significantly increased relative to advanced tumor stage (P<0.001, Cochran-Mantel-Haenszel test). Moreover, patients with SCC with aPKCλ/ι nuclear localization had worse prognoses than those with cytoplasmic localization (P<0.001, log-rank test). aPKCλ/ι localization differed between the intraepithelial lesion and adjacent invasive cancer in 40% of cases, while the expression pattern was similar between primary and matched metastatic tumors. In conclusion, aPKCλ/ι nuclear localization in cervical cancer is associated with tumor progression and worse prognosis. This is the first report to show aberrant nuclear aPKCλ/ι localization in a subgroup of cervical cancer patients and its association with worse prognosis.

Size-Based Differentiation of Cancer and Normal Cells by a Particle Size Analyzer Assisted by a Cell-Recognition PC Software.

Detection of anomalous cells such as cancer cells from normal blood cells has the potential to contribute greatly to cancer diagnosis and therapy. Conventional methods for the detection of cancer cells are usually tedious and cumbersome. Herein, we report on the use of a particle size analyzer for the convenient size-based differentiation of cancer cells from normal cells. Measurements made using a particle size analyzer revealed that size parameters for cancer cells are significantly greater (e.g., inner diameter and width) than the corresponding values for normal cells (white blood cells (WBC), lymphocytes and splenocytes), with no significant difference in shape parameters (e.g., circularity and convexity). The inner diameter of many cancer cell lines is greater than 10 µm, in contrast to normal cells. For the detection of WBC having similar size to that of cancer cells, we developed a PC software "Cancer Cell Finder" that differentiates them from cancer cells based on brightness stationary points on a cell surface. Furthermore, the aforementioned method was validated for cancer cell/clusters detection in spiked mouse blood samples (a B16 melanoma mouse xenograft model) and circulating tumor cell cluster-like particles in the cat and dog (diagnosed with cancer) blood samples. These results provide insights into the possible applicability of the use of a particle size analyzer in conjunction with PC software for the convenient detection of cancer cells in experimental and clinical samples for theranostics.

Regulation of epithelial cell polarity by PAR-3 depends on Girdin transcription and Girdin-Gαi3 signaling.

Epithelial apicobasal polarity has fundamental roles in epithelial physiology and morphogenesis. The PAR complex, comprising PAR-3, PAR-6 and atypical protein kinase C (aPKC), is involved in determining cell polarity in various biological contexts, including in epithelial cells. However, it is not fully understood how the PAR complex induces apicobasal polarity. In this study, we found that PAR-3 regulates the protein expression of Girdin (also known as GIV or CCDC88A), a guanine-nucleotide-exchange factor (GEF) for heterotrimeric Gαi subunits, at the transcriptional level by cooperating with the AP-2 transcription factor. In addition, we confirmed that PAR-3 physically interacts with Girdin, and show that Girdin, together with the Gαi3 (also known as GNAI3), controls tight junction formation, apical domain development and actin organization downstream of PAR-3. Taken together, our findings suggest that transcriptional upregulation of Girdin expression and Girdin-Gαi3 signaling play crucial roles in regulating epithelial apicobasal polarity through the PAR complex.

Regulation of asymmetric division and CD8+ T lymphocyte fate specification by protein kinase Cζ and protein kinase Cλ/ι.

During an immune response against a microbial pathogen, activated naive T lymphocytes give rise to effector cells that provide acute host defense and memory cells that provide long-lived immunity. It has been shown that T lymphocytes can undergo asymmetric division, enabling the daughter cells to inherit unequal amounts of fate-determining proteins and thereby acquire distinct fates from their inception. In this study, we show that the absence of the atypical protein kinase C (PKC) isoforms, PKCζ and PKCλ/ι, disrupts asymmetric CD8(+) T lymphocyte division. These alterations were associated with aberrant acquisition of a pre-effector transcriptional program, detected by single-cell gene expression analyses, in lymphocytes that had undergone their first division in vivo and enhanced differentiation toward effector fates at the expense of memory fates. Together, these results demonstrate a role for atypical PKC in regulating asymmetric division and the specification of divergent CD8(+) T lymphocyte fates early during an immune response.

Aberrant Expression of the Cell Polarity Regulator aPKCλ/ι is Associated With Disease Progression in Cervical Intraepithelial Neoplasia (CIN): A Possible Marker for Predicting CIN Prognosis.

Atypical protein kinase C λ/ι (aPKCλ/ι) is a regulator of epithelial cellular polarity. It is also overexpressed in several cancers and functions in cell proliferation and invasion. Therefore, we hypothesized that aPKCλ/ι may be involved in development and progression of cervical intraepithelial neoplasia (CIN), the precancerous disease of cervical cancer induced by human papillomavirus. To do this, we investigated the relationship between aPKCλ/ι expression and CIN. aPKCλ/ι expression level and subcellular localization were assessed in 192 CIN biopsy samples and 13 normal epithelial samples using immunohistochemistry. aPKCλ/ι overexpression (normal epithelium, 7.7%; CIN1, 41.7%; CIN2/3, 76.4%) and aPKCλ/ι nuclear localization (normal epithelium, 0.0%; CIN1, 36.9%; CIN2/3, 78.7%) were higher in CIN samples than normal samples (P<0.05), suggesting that CIN grade is related to aPKCλ/ι overexpression and nuclear localization. Then, 140 CIN cases were retrospectively analyzed for 4-yr cumulative disease progression and regression rates using the Cox proportional hazards model. CIN1 cases with aPKCλ/ι overexpression or aPKCλ/ι nuclear localization had a higher progression rate than CIN1 cases with normal aPKCλ/ι expression levels or cytoplasmic localization (62.5% vs. 9.7% and 63.1% vs. 9.4%, respectively; P<0.001). Multivariate analysis indicated that human papillomavirus types 16 and 18, aPKCλ/ι overexpression (hazard ratio=4.26; 95% confidence interval, 1.50-12.1; P=0.007), and aPKCλ/ι nuclear localization (hazard ratio=3.59; 95% confidence interval, 1.24-10.4; P=0.019) were independent risk factors for CIN1 progression. In conclusion, aPKCλ/ι could be useful for the therapeutic management of patients with CIN, particularly those with non-human papillomavirus 16/18 types.

Proteomic analysis of proteins related to prognosis of lung adenocarcinoma.

We attempted to identify prognosis-related proteins expressed in early resection lung adenocarcinomas that had higher metastatic potential. Early resection of lung adenocarcinoma tissues were collected from patients who experienced recurrence within 5 years after surgery; these patients are defined here as the poor prognosis group. From these samples, we prepared frozen tissue sections and then isolated cancerous areas by laser capture microdissection to allow extraction of cancer tissue-derived soluble proteins. Shotgun LC-MS/MS analysis detected and identified a total of 875 proteins in these cancer tissues. Relative quantitative analysis revealed that 17 proteins were preferentially expressed in the poor prognosis group relative to the good prognosis group, which consisted of patients who did not exhibit recurrence. Among them, 14-3-3 beta/alpha and calnexin were reported to be potentially involved in tumor recurrence and the malignant properties of lung cancer. Here immunological analyses confirmed disease-associated expression of these proteins. In a cell-culture model using A549, targeted depletion of either 14-3-3 beta/alpha or calnexin reduced proliferation, invasion, and migration, suggesting that both proteins are involved in determining the malignant properties of lung cancer that contribute to poor prognosis.

Identification of a Gene Expression Signature to Predict the Risk of Early Recurrence and the Degree of Immune Cell Infiltration in Triple-negative Breast Cancer.

BACKGROUND/AIM: Patients with triple-negative breast cancer (TNBC) have a high rate of recurrence within 3 years of diagnosis and a high rate of death within 5 years compared to other subtypes. The number of clinical trials investigating various new agents and combination therapies has recently increased; however, current strategies benefit only a minority of patients. This study aimed to identify specific genes that predict patients at high risk of recurrence and the immune status of the tumor microenvironment at an early stage, thereby providing insight into potential therapeutic targets to improve clinical outcomes in TNBC patients. MATERIALS AND METHODS: We evaluated the prognostic significance of microarray mRNA expression of 20,603 genes in 233 TNBC patients from the METABRIC dataset and further validated the results using RNA-seq mRNA expression data in 143 TNBC patients from the GSE96058 dataset. RESULTS: Eighteen differentially expressed genes (AKNA, ARHGAP30, CA9, CD3D, CD3G, CD6, CXCR6, CYSLTR1, DOCK10, ENO1, FLT3LG, IFNG, IL2RB, LPXN, PRKCB, PVRIG, RASSF5, and STAT4) identified in both datasets were found to be reliable biomarkers for predicting TNBC recurrence and progression. Notably, the genes whose low expression was associated with increased risk of recurrence and death were immune-related genes, with significant differences in levels of immune cell infiltration in the tumor microenvironment between high- and low- expression groups. CONCLUSION: Genes reported herein may be effective biomarkers to identify TNBC patients who will and will not benefit from immunotherapy and may be particularly important genes for developing future treatment strategies, including immunotherapy.

Luminal B Breast Cancer Coexpressing p62 and ALDH1A3 Is Less Susceptible to Radiotherapy.

BACKGROUND/AIM: We have reported that p62 (also known as sequestosome 1) is needed for survival/proliferation and tumor formation by aldehyde dehydrogenase 1 (ALDH1) -positive cancer stem cells (CSCs) and that p62high ALDH1A3high expression is associated with a poor prognosis in luminal B breast cancer. However, the association between p62high ALDH1A3high and the benefit from radiotherapy in patients with luminal B breast cancer remains unclear. MATERIALS AND METHODS: Datasets from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and The Cancer Genome Atlas (TCGA) were downloaded, and data from p62high ALDH1A3high luminal B patients treated without or with radiotherapy were analyzed by Kaplan-Meier and multivariate Cox regression analyses. We also performed an in vitro tumor sphere formation assay after X-ray irradiation using p62-knockdown ALDH1high luminal B BT-474 cells. RESULTS: p62high ALDH1A3high patients had poorer clinical outcomes than other luminal B breast cancer patients treated with radiotherapy. The combination of p62 DsiRNA KD and X-ray irradiation suppressed in vitro tumor sphere formation by ALDH1high BT-474 cells. These results suggest that p62 is involved in the reduced effect of X-ray irradiation on ALDH1-positive luminal B breast CSCs. CONCLUSION: p62 and ALDH1A3 may serve as prognostic biomarkers for luminal B breast cancer patients treated with radiotherapy. Additionally, the combination of p62 inhibition and radiotherapy could be useful for targeted strategies against ALDH1-positive luminal B breast CSCs.

High expression of KIBRA in low atypical protein kinase C-expressing gastric cancer correlates with lymphatic invasion and poor prognosis.

Overexpression of atypical protein kinase Cλ/ι (aPKCλ/ι), a regulator of cell polarity, is frequently associated with the poor prognoses of several cancers, including gastric cancer. Recent studies revealed a molecular link between aPKC and KIBRA, an upstream regulator of tumor suppressor Hippo pathway that regulates cell proliferation and apoptosis. Further, KIBRA directly inhibits the kinase activity of aPKC to regulate epithelial cell polarity. These observations suggest that the KIBRA-aPKC connection plays a role in cancer progression; however, clinical significance of the correlation between these factors remains unclear. Here we examined the correlation between KIBRA/aPKCλ/ι expression, as detected by immunohistochemistry, and clinicopathological outcomes in 164 gastric cancer patients using Fisher's exact test and Kaplan-Meier log-rank test. We found an intimate correlation between the expression level of KIBRA and aPKCλ/ι (P = 0.012). Furthermore, high expression of KIBRA is correlated with lymphatic (P = 0.046) and venous invasion (P = 0.039). The expression level of KIBRA by itself did not correlate with the prognosis; however, high expression of KIBRA in low aPKCλ/ι-expressing gastric cancer correlated with disease-specific (P = 0.037) and relapse-free survival (P = 0.041) by Kaplan-Meier with log-rank test and higher lymphatic invasion cases by Fisher's exact test (P = 0.042). Furthermore, overexpression of the aPKC-binding region of KIBRA disrupted tight junctions in epithelial cells. These results suggest that high expression of KIBRA in low aPKC-expressing cells causes massive loss of aPKC activity, leading to loss of polarity and invasiveness of gastric cancer cells.

Cleavage of the interchain disulfide bonds in rituximab increases its affinity for FcγRIIIA.

The Fc region of human IgG1 mediates effector function via binding to Fcγ receptors and complement activation. The H and L chains of IgG1 antibodies are joined by four interchain disulfide bonds. In this study, these bonds within the therapeutic IgG1 rituximab (RTX) were cleaved either by mild reduction followed by alkylation or by mild S-sulfonation; consequently, two modified RTXs - A-RTX (alkylated) and S-RTX (S-sulfonated) - were formed, and both were almost as potent as unmodified RTX when binding CD20 antigen. Unexpectedly, each modified RTX had a higher binding affinity for FcγRIIIA (CD16A) than did unmodified RTX. However, S-RTX and A-RTX were each less potent than RTX in an assay of antibody-dependent cellular cytotoxicity (ADCC). In this ADCC assay, each modified RTX showed decreased secretion of granzyme B, but no change in perforin secretion, from effector cells. These results provide significant information on the structures within IgG1 that are involved in binding FcγRIIIA, and they may be useful in the development of therapeutic antagonists for FcγRIIIA.

aPKCλ/ι is a beneficial prognostic marker for pancreatic neoplasms.

Pancreatic cancer is a lethal disease. Overall survival is typically 6 months from diagnosis. Determination of prognostic factors in pancreatic cancer that would allow identification of patients who could potentially benefit from aggressive treatment is important. However, until date, there are no established reliable prognostic factors for pancreatic cancer patients. Herein, we propose a beneficial biomarker which is significantly correlated with the prognosis in pancreatic cancer patients. Atypical protein kinase C λ/ι (aPKCλ/ι) is overexpressed and has been implicated in the progression of several cancers. We tested the expression levels of aPKCλ/ι in two types of pancreatic neoplasm, pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasms (IPMNs), by immunohistochemistry. Examination of the aPKCλ/ι expression levels in surgically resected specimens of PDCA (n = 115) demonstrated that the expression levels of aPKCλ/ιin PDAC had prognostic implications, independent of the Tumor-Node-Metastasis classification and World Health Organization tumor grade. In the case of IPMNs (n = 46) also, the expression levels of aPKCλ/ιin IPMN were found to be of prognostic importance, independent of the World Health Organization histological grade or morphological type. Interestingly, high expression levels of aPKCλ/ι were significantly correlated with a worse histological grade (p = 0.010) and advanced stage of the tumor (p = 0.0050) in IPMN patients. These findings suggest that high expression levels of aPKCλ/ι could be involved in the malignant transformation of IPMNs. Based on these observations, we propose the expression level of aPKCλ/ι as a prognostic marker common to different types of pancreatic neoplasms.

Association of PSA variability with prostate cancer development using large-scale medical information data: a retrospective cohort study.

BACKGROUND: Prostate cancer is one of the most common cancers among men worldwide and the fourth most common cause of death. The number of prostate cancer cases and deaths is increasing every year because of population aging. This study aimed to clarify the risk of developing prostate cancer due to fluctuations in Prostate Specific Antigen (PSA) levels in patients without a history of prostate cancer using large medical information data. RESULTS: This retrospective cohort included 1707 male patients aged 60 years or older who had a PSA level measurement date (2-PSA) within 3 months or more and 2 years from the first PSA level measurement date (1-PSA) in the database between 2008 and 2019. We subtracted 1-PSA from 2-PSA and designated patients with a higher 2-PSA than 1-PSA to the "up" group (n = 967) and patients with a lower 2-PSA than 1-PSA to the "down" group (n = 740). By using Cox proportional hazards model, a significant increase in prostate cancer risk was observed in the up group compared with the down group (adjusted hazard ratio [HR] = 1.82, 95% confidence interval [CI] = 1.21-2.72; adjusted for patient background factors). Subgroup analysis showed that patients with PSA levels < 4 ng/mL had a significantly increased risk of developing prostate cancer if the next PSA level increases by approximately 20% (adjusted HR = 2.94, 95% CI = 1.14-7.58), and patients with PSA levels of 4 ng/mL or higher if the next PSA level is decreased by approximately 20% had a significantly reduced risk of developing prostate cancer (adjusted HR = 0.36, 95% CI = 0.18-0.74), compared to that with no change. CONCLUSIONS: This is the first study to clarify the association between PSA variability and risk of developing prostate cancer in patients without a history of prostate cancer. These results suggest that the suppression of elevated PSA levels may lead to the prevention of prostate cancer and that it would be better to perform a biopsy because the risk of developing prostate cancer may increase in the future if the PSA value increases above a certain level.

Angiotensin II Receptor Blockers Cause Changes in Prostate-specific Antigen Levels: A Retrospective Cohort Study.

BACKGROUND/AIM: We previously reported a decrease in prostate-specific antigen (PSA) levels in patients with castration-resistant prostate cancer treated with angiotensin II receptor blockers (ARBs). However, no studies have reported the effect of ARBs on PSA variability in patients without a history of prostate cancer. Therefore, we conducted a population-based, retrospective study to determine whether ARBs have an inhibitory effect on elevated PSA levels in Japanese patients without a history of prostate cancer. PATIENTS AND METHODS: This study was conducted using a large-scale Japanese claim database, including male patients aged ≥60 years who had two or more PSA measurements with an interval between measurements of 3 months to 2 years between April 2008 and June 2019. Patients who had been prescribed ARBs were grouped into the ARB group, and those who were prescribed antihypertensive drugs other than ARBs were grouped into the non-ARB group. We compared the proportions of patients with second PSA levels greater than the first. The numbers of eligible patients in the ARB and non-ARB groups were 777 and 527, respectively. RESULTS: Multivariate logistic regression analysis revealed that the proportion of patients with elevated PSA levels was significantly lower in the ARB group than in the non-ARB group (adjusted odds ratio=0.80, 95% confidence interval=0.64-0.99, p=0.047). CONCLUSION: ARBs may suppress elevated PSA levels in patients without a history of prostate cancer. This contributes to the prevention of prostate cancer.

High SLC20A1 Expression Indicates Poor Prognosis in Prostate Cancer.

BACKGROUND/AIM: High expression of solute carrier family 20 member 1 (SLC20A1) indicates poor clinical outcomes for patients with breast cancer subtypes treated with endocrine therapy and radiotherapy. However, the association between SLC20A1 expression and clinical outcomes in prostate cancer remains to be determined. MATERIALS AND METHODS: Open-source datasets (The Cancer Genome Atlas prostate, Stand Up to Cancer-Prostate Cancer Foundation Dream Team, and The Cancer Genome Atlas PanCancer Atlas) were downloaded and analyzed. SLC20A1 expression was analyzed in prostate cancer and normal prostate tissue. Survival analysis using Kaplan-Meier curves and Cox regression analysis were performed to examine patient prognosis, as well as the effects of endocrine therapy and radiotherapy on high SLC20A1 expression in patients with prostate cancer. RESULTS: SLC20A1 was higher in prostate cancer than in normal prostate tissues. High SLC20A1 expression predicted poor disease-free and progression-free survival. Following endocrine therapy, no significant difference in prognosis was observed between patients with high SLC20A1 and those with low SLC20A1 expression. However, following radiotherapy, high SLC20A1 expression tended to be associated with a poor clinical outcome. CONCLUSION: SLC20A1 may serve as a prognostic biomarker for prostate cancer, and the recommended treatment for patients with high SLC20A1 expression is endocrine therapy.

aPKClambda/iota promotes growth of prostate cancer cells in an autocrine manner through transcriptional activation of interleukin-6.

Understanding the mechanism by which hormone refractory prostate cancer (HRPC) develops remains a major issue. Alterations in HRPC include androgen receptor (AR) changes. In addition, the AR is activated by cytokines such as interleukin-6 (IL-6). Atypical protein kinase C (aPKClambda/iota) has been implicated in the progression of several cancers. Herein, we provide evidence that aPKClambda/iota expression correlates with prostate cancer recurrence. Experiments in vitro and in vivo revealed aPKClambda/iota to be involved in prostate cancer cell growth through secretion of IL-6. Further, aPKClambda/iota activates transcription of the IL-6 gene through NFkappaB and AP-1. We conclude that aPKClambda/iota promotes the growth of hormone independent prostate cancer cells by stimulating IL-6 production in an autocrine manner. Our findings not only explain the link between aPKClambda/iota and IL-6, implicated in the progression a variety of cancers, but also establish a molecular change involved in the development of HRPC. Further, aPKClambda/iota expression might be a biomarker for prostate cancer progression.

High expression of SLC20A1 is less effective for endocrine therapy and predicts late recurrence in ER-positive breast cancer.

Estrogen receptor-positive (ER+) breast cancer intrinsically confers satisfactory clinical outcomes in response to endocrine therapy. However, a significant proportion of patients with ER+ breast cancer do not respond well to this treatment. Therefore, to evaluate the effects of endocrine therapy, there is a need for identification of novel markers that can be used at the time of diagnosis for predicting clinical outcomes, especially for early-stage and late recurrence. Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter that has been proposed to be a viable prognostic marker for the luminal A and luminal B types of ER+ breast cancer. In the present study, we examined the possible association of SLC20A1 expression with tumor staging, endocrine therapy and chemotherapy in the luminal A and luminal B subtypes of breast cancer. In addition, we analyzed the relationship between SLC20A1 expression and late recurrence in patients with luminal A and luminal B breast cancer following endocrine therapy. We showed that patients with higher levels of SLC20A1 expression (SLC20A1high) exhibited poorer clinical outcomes in those with tumor stage I luminal A breast cancer. In addition, this SLC20A1high subgroup of patients exhibited less responses to endocrine therapy, specifically in those with the luminal A and luminal B subtypes of breast cancer. However, patients with SLC20A1high showed good clinical outcomes following chemotherapy. Patients tested to be in the SLC20A1high group at the time of diagnosis also showed a higher incidence of recurrence compared with those with lower expression levels of SLC20A1, at >15 years for luminal A breast cancer and at 10-15 years for luminal B breast cancer. Therefore, we conclude that SLC20A1high can be used as a prognostic biomarker for predicting the efficacy of endocrine therapy and late recurrence for ER+ breast cancer.

High SLC20A1 Expression Is Associated With Poor Prognosis for Radiotherapy of Estrogen Receptor-positive Breast Cancer.

BACKGROUND/AIM: Radiotherapy is one of the main treatments for estrogen receptor-positive (ER+) breast cancer. However, in some ER+ breast cancer cases, radiotherapy is insufficient to inhibit progression and there is a lack of markers to predict radiotherapy insensitivity. Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter, which has been proposed to be a viable prognostic marker for luminal A and B types of ER+ breast cancer. The present study examined the possibility of SLC20A1 as a novel biomarker for the prediction of radiotherapy efficiency. PATIENTS AND METHODS: The Molecular Taxonomy of Breast Cancer International Consortium dataset was downloaded from cBioportal and the prognosis of patients with high SLC20A1 expression (SLC20A1 high ) was compared with that of patients with low SLC20A1 expression, without or with radiotherapy and tumor stages I, II, and III, using the Kaplan-Meier method and multivariate Cox regression analyses of disease-specific and relapse-free survival. RESULTS: Patients in the SLC20A1 high group with radiotherapy showed poor clinical outcomes in both luminal A and luminal B breast cancers. Furthermore, in luminal A breast cancer at tumor stage I, patients in the SLC20A1 high  group with radiotherapy also showed poor clinical outcomes. Therefore, these results suggest that radiotherapy is insufficient for patients in the SLC20A1 high group for both luminal A and B types, and especially for the luminal A type at tumor stage I. CONCLUSION: SLC20A1 can be used as a prognostic marker for the prediction of the efficacy of radiotherapy for luminal A and luminal B breast cancers.

High Expression of CD58 and ALDH1A3 Predicts a Poor Prognosis in Basal-like Breast Cancer.

BACKGROUND/AIM: CD58 is an immune adhesion molecule on the cellular surface. It was previously found that a high expression of CD58 predicted a poor prognosis of patients with lower-grade gliomas. Therefore, the aim of this paper was to investigate the association between CD58 and breast cancer. MATERIALS AND METHODS: CD58 gene expression data downloaded from cBioPortal was compared between the different subtypes of breast cancer. Clinical prognosis was examined using Kaplan-Meier analysis and multivariable Cox regression analysis. The association between CD58 expression and immune cell infiltration was estimated using the TIMER 2.0 web platform. Finally, the tumour sphere formation of aldehyde dehydrogenase 1 (ALDH1)high basal-like breast cancer stem cells in which CD58 was knocked down using siRNA was measured. RESULTS: CD58 mRNA was mainly enriched in claudin-low and basal-like subtypes. The high expression of CD58 predicted a good prognosis in patients with luminal A and luminal B breast cancer. This prediction may be due to the association of immune cell infiltration with CD58. Notably, patients with luminal A breast cancer with a high expression of CD58 in association with ALDH1A3 exhibited a good prognosis; however, this did not apply to patients with basal-like breast cancer. The in vitro experiments revealed that knockdown of CD58 inhibited the tumour sphere formation ability of ALDH1high basal-like cancer cells. CONCLUSION: CD58 may function as a potential prognostic biomarker and therapeutic target in ALDH-positive basal-like cancer stem cells.