Impact of media compositions and culture systems on the immunophenotypes of patient-derived breast cancer cells.

BACKGROUND: Heterogeneous tumor cells are thought to be a significant factor in the failure of endocrine therapy in estrogen receptor-positive (ER+) cancers. Culturing patient-derived breast cancer cells (PDBCCs) provides an invaluable tool in pre-clinical and translational research for the heterogeneity of cancer cells. This study aimed to investigate the effects of different media components and culture methods on the BCSC-associated immunophenotypes and gene expression in ER + PDBCCs. METHODS: Ten patients with ER + breast cancer were employed in this study, six of whom had neoadjuvant chemotherapy and four of whom did not. PDBCCs were isolated by enzymatic methods using collagen I and hyaluronidase. PDBCCs were grown as monolayers in mediums with different compositions and as multicellular spheroid in a suspended condition. Collagen I-coated plate and ultralow attachment plate coated with polymer-X were used for monolayer and spheroid culture. Flow cytometry, immunofluorescent staining, RT-PCR, and RNA-sequencing were employed to examine the immunophenotype and genetic profile of PDBCCs. RESULTS: More than 95% of PDBCCs sustain EpCAM high/+/fibroblast marker- phenotypes in monolayer conditions by subculturing 3-4 times. A83-01 removal induced senescent cells with high ß-galactosidase activity. PDBCCs grown as monolayers were characterized by the majority of cells having an EpCAM+/CD49f + phenotype. Compared to full media in monolayer culture, EGF removal increased EpCAM+/CD49f - phenotype (13.8-fold, p = 0.028), whereas R-spondin removal reduced it (0.8-fold, p = 0.02). A83-01 removal increased EpCAM+/CD24 + phenotype (1.82-fold, p = 0.023) and decreased EpCAM low/-/CD44+/CD24- phenotype (0.45-fold, p = 0.026). Compared to monolayer, spheroid resulted in a significant increase in the population with EpCAM-/CD49+ (14.6-fold, p = 0.006) and EpCAM low/-/CD44+/CD24- phenotypes (4.16-fold, p = 0.022) and ALDH high activity (9.66-fold, p = 0.037). ALDH1A and EMT-related genes were upregulated. In RNA-sequencing analysis between spheroids and monolayers, a total of 561 differentially expressed genes (2-fold change, p < 0.05) were enriched in 27 KEGG pathways including signaling pathways regulating pluripotency of stem cells. In a recurrence-free survival analysis based on the Kaplan-Meier Plotter database of the up-and down-regulated genes identified in spheroids, 15 up-, and 14 down-regulated genes were associated with poor prognosis of breast cancer patients. CONCLUSION: The media composition and spheroid culture method change in the BCSCs and EMT markers of PDBCCs, implying the importance of defining the media composition and culture method for studying PDBCCs in vitro.

Racial differences in predictive value of the 21-gene recurrence score assay: a population-based study using the SEER database.

PURPOSE: The 21-gene recurrence score (RS) assay is currently used for predicting chemotherapeutic benefits for hormone receptor-positive (HR +) early-stage breast cancer patients without consideration regarding racial differences in that predictive value. This study aimed at demonstrating racial differences in the predictive values of the 21-gene RS assay. METHODS: The study cohort was selected from the Surveillance, Epidemiology, and End Results (SEER) database. Breast cancer-specific mortality (BCSM) was compared between patients who received chemotherapy (the "CTx group") and those who did not (the "no CTx group") to estimate the predictive value of the assay. This comparison was repeated for each racial group. RESULTS: Among 88,498 T1 - 2N0 HR + breast cancer patients who had results of 21-gene RS, 13,123 patients had RS > 25, which included 10,697 Whites, 1282 Blacks, and 1,144 Asian Americans/Pacific Islanders (AAPIs). Chemotherapy was administered to 8364 patients (63.4%). The adjusted hazard ratio for BCSM in the CTx group (vs. no CTx group) was 0.734 (95% confidence interval [CI] 0.588-0.917) in Whites, 0.748 (95% CI 0.428-1.307) in Blacks, and 1.343 (95% CI 0.558-3.233) in AAPIs. No subgroup within patients with RS > 25 among non-White women showed a significant predictive value of the 21-gene RS assay, except for Black women with grade 3 tumors. CONCLUSION: The predictive value of the 21-gene RS assay for assessing chemotherapy benefit was validated in White women based on the SEER database, although the predictive value was not warranted in non-White women.

Comparative characterization of 3D chromatin organization in triple-negative breast cancers.

Triple-negative breast cancer (TNBC) is a malignant cancer subtype with a high risk of recurrence and an aggressive phenotype compared to other breast cancer subtypes. Although many breast cancer studies conducted to date have investigated genetic variations and differential target gene expression, how 3D chromatin architectures are reorganized in TNBC has been poorly elucidated. Here, using in situ Hi-C technology, we characterized the 3D chromatin organization in cells representing five distinct subtypes of breast cancer (including TNBC) compared to that in normal cells. We found that the global and local 3D architectures were severely disrupted in breast cancer. TNBC cell lines (especially BT549 cells) showed the most dramatic changes relative to normal cells. Importantly, we detected CTCF-dependent TNBC-susceptible losses/gains of 3D chromatin organization and found that these changes were strongly associated with perturbed chromatin accessibility and transcriptional dysregulation. In TNBC tissue, 3D chromatin disorganization was also observed relative to the 3D chromatin organization in normal tissues. We observed that the perturbed local 3D architectures found in TNBC cells were partially conserved in TNBC tissues. Finally, we discovered distinct tissue-specific chromatin loops by comparing normal and TNBC tissues. In this study, we elucidated the characteristics of the 3D chromatin organization in breast cancer relative to normal cells/tissues at multiple scales and identified associations between disrupted structures and various epigenetic features and transcriptomes. Collectively, our findings reveal important 3D chromatin structural features for future diagnostic and therapeutic studies of TNBC.

Targeting CLK4 inhibits the metastasis and progression of breast cancer by inactivating TGF-ß pathway.

Triple-negative breast cancer (TNBC) represents the most aggressive subtype of breast cancer that is highly resistant to current therapeutic options. According to the public databases Oncomine and KM plotter, the CLK4 expression is correlated with poor patient survival in TNBC, especially in mesenchymal-like TNBC (MES-TNBC) that has strong metastatic potential. Therefore, we investigated the potential involvement of CLK4 in the metastasis and progression of MES-TNBC. In the MES-TNBC cell lines, the CLK4 expression was elevated. Notably, the RNAi-mediated silencing of CLK4 reduced the expression of multiple epithelial-mesenchymal transition (EMT) genes that mediate metastasis. Furthermore, CLK4 silencing reduced both the invasive behaviors of the cultured cells and tumor metastasis in the mouse xenograft model. It is also noteworthy that CLK4 silencing repressed the invasive and cancer stem cell (CSC) properties that are induced by the TGF-ß signaling. Importantly, the pharmacological inhibition of CLK4 potently repressed the invasion and proliferation of MES-TNBC cell lines and patient-derived cells, which demonstrates its clinical applicability. Collectively, our results suggest that CLK4 plays a crucial role in invasion and proliferation of MES-TNBC, especially in the processes that are induced by TGF-ß. Also, this study characterizes CLK4 as a novel therapeutic target in breast cancer.

The Emotional Status, Attitudes in Decision-Making Process, and Their Impact on Surgical Choices in Korean Breast Cancer Patients.

PURPOSE: We examined the incidence of emotional distress in women with newly diagnosed breast cancer to determine whether the degree of emotional distress affected their choice of breast-conserving surgery (BCS) or mastectomy and evaluated how the patient's preferred role in decision-making influenced her choice of surgical method. METHODS: This prospective study included 85 patients newly diagnosed with in situ or invasive breast cancer eligible for BCS. Their degree of depression/anxiety and attitude toward the decision-making process were measured using the Hospital Anxiety and Depression Scale (HADS) and Control Preference Scale (CPS), respectively. After receiving information on both surgical methods, the patients indicated their preferred surgical method and completed the CPS at their initial and second visits before surgery. RESULTS: After the diagnosis of breast cancer, 75.3% of patients showed abnormal or borderline HADS scores for depression and 41.2% for anxiety. Patients with borderline or abnormal degrees of depression were more likely to have coexisting abnormal degrees of anxiety (p < 0.001). However, the presence of depression or anxiety was not associated with patients' surgical choices (p=0.394 and 0.530, respectively). Patients who preferred a more active role in the decision-making process were more likely to choose mastectomy over BCS, while those who were passive or collaborative chose BCS more frequently (p=0.001). CONCLUSION: Although many patients with newly diagnosed breast cancer experience depression and anxiety before surgery, these do not affect the choice of surgical method; however, their attitudes toward the decision-making process do.

Resident Learning Curve for Laparoscopic Appendectomy According to Seniority.

PURPOSE: To delineate the learning curve (LC) for laparoscopic appendectomy (LA) performed by residents according to seniority in training. METHODS: Between October 2015 and November 2016, 150 patients underwent LA by three residents (in their first, second, and third year of training) under supervision. The patients were non-randomly assigned to each resident. The data were reviewed and analyzed retrospectively from prospectively collected database. The perioperative outcomes were compared between the three residents including operation time, complication, conversion, and so on. The LCs were evaluated by the moving average method and cumulative sum control chart (CUSUM) for operation time and surgical completion. RESULTS: Baseline characteristics and perioperative outcomes were similar except for age and location of the appendix among the three groups. Operation time was not different among the three residents (43.9, 45.3, and 48.4 min for A, B, and C, respectively). The moving average method for operation time showed a decreasing tendency for all residents. CUSUM for operation time showed that the peak points occurred at the 24th, 18th, and 31st cases for resident A, B, and C, respectively. In terms of surgical failure, residents A, B, and C reached steady states after the 35th, 11th, and 16th cases, respectively. Perforation of the appendix base was the only risk factor for surgical failure. CONCLUSION: The LC for LA by residents was 11-35 cases according to multidimensional statistical analyses. The accumulation of surgical experience of residents might affect the LC, especially for surgical completion rather than for operation time.

Long-term prognostic effect of hormone receptor subtype on breast cancer.

PURPOSE: To determine the long-term prognostic role of hormone receptor subtype in breast cancer using surveillance, epidemiology, and end results (SEER) database. METHODS: Data of 810,587 female operable invasive breast cancer patients from SEER database with a mean follow-up period of 94.2 months (range, 0-311 months) were analyzed. Hormone receptor subtype was classified into four groups based on estrogen receptor (ER) and progesterone receptor (PR) statuses: ER(+)/PR(+), ER(+)/PR(-), ER(-)/PR(+), and ER(-)/PR(-). RESULTS: Numbers of subjects with ER(+)/PR(+), ER(+)/PR(-), ER(-)/PR(+), ER(-)/PR(-), and unknown were 496,279 (61.2%), 86,858 (10.7%), 11,545 (1.4%), 135,441 (16.7%), and 80,464 (9.9%), respectively. The ER(+)/PR(+) subtype showed the best breast-cancer-specific survival, followed by ER(+)/PR(-), ER(-)/PR(+), and ER(-)/PR(-) subtypes in the respective order (all p < 0.001). Survival difference among hormone receptor subtypes was maintained in subgroup analysis according to anatomic stage, race, age group, and year of diagnosis. Hormone receptor subtype was a significant independent prognostic factor in multivariable analyses (p < 0.001). Hazard ratios of ER(+)/PR(-), ER(-)/PR(+), and ER(-)/PR(-) for breast-cancer-specific mortality risk were 1.419 (95% confidence interval [CI] 1.383-1.456), 1.630 (95% CI 1.537-1.729), and 1.811 (95% CI 1.773-1.848), respectively, with ER(+)/PR(+) as reference. CONCLUSION: Hormone receptor subtype is a significant independent prognostic factor in female operable invasive breast cancer patients with long-term effect. The ER(+)/PR(+) subtype shows the most favorable prognosis, followed by ER(+)/PR(-), ER(-)/PR(+), and ER(-)/PR(-) subtypes in the respective order. Prognostic impacts of hormone receptor subtypes are also maintained in subgroup analysis according to anatomic stage, race, age, and year of diagnosis.

Prognostic Role of KRAS mRNA Expression in Breast Cancer.

PURPOSE: We investigated the prognostic role of KRAS mRNA expression in breast cancer using The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) databases. METHODS: Clinical and biological data of 1,093 breast cancers from TCGA database and 1,904 breast cancers from METABRIC database were analyzed. Overall survival (OS) and breast cancer-specific survival (BCSS) were determined. RESULTS: The group with high KRAS mRNA expression showed worse survival than the group with low KRAS mRNA expression regarding both OS (p = 0.012 in TCGA, p < 0.001 in METABRIC) and BCSS (p = 0.001 in METABRIC). According to multivariate analysis, the level of KRAS mRNA expression was an independent prognostic factor in both TCGA (hazard ratio [HR], 1.570; 95% confidence interval [CI], 1.026-2.403; p = 0.038) and METABRIC (HR, 1.254; 95% CI, 1.087-1.446; p = 0.002) databases. The prognostic impact of mRNA expression was effective only for luminal A subtype (p < 0.001 in METABRIC). Positive correlation was observed between mRNA expression and copy number alteration (CNA) (r = 0.577, p < 0.001 in TCGA; ρ = 0.343, p < 0.001 in METABRIC). Methylation showed negative correlations with both mRNA expression and CNA (r = -0.272, p < 0.001 in TCGA). The expression of mRNA had little association with the mutation status in breast cancers, having a mutation frequency of approximately 0.6%. CONCLUSION: KRAS mRNA expression was significantly associated with breast cancer prognosis. It was found to be an independent prognostic factor for breast cancer. Prognostic role of KRAS mRNA expression was effective only in luminal A subtype. Further studies are needed to validate the prognostic role of KRAS mRNA expression in breast cancer, thus paving a way for clinical application of KRAS in practice.

Clinical Outcomes of Radiofrequency Ablation for Unilateral and Bilateral Varicose Veins.

BACKGROUND: Approximately 20% of varicose vein are bilateral. Patients prefer a simultaneous bilateral procedure instead of 2 separate unilateral procedures. There is currently little evidence comparing bilateral and unilateral varicose vein surgeries. OBJECTIVE: To report the clinical outcomes of unilateral and bilateral radiofrequency ablation (RFA) for varicose veins. MATERIALS AND METHODS: The authors retrospectively collected data on clinical outcomes of patients who underwent RFA. They investigated clinical, etiologic, anatomic, and pathophysiologic (CEAP) score, venous clinical severity score (VCSS), and quality of life (QoL) score. RESULTS: Radiofrequency ablation was performed in 546 limbs in 385 patients. Women comprised 60.4% of the patients. The mean age was 52.3 ± 11.6 years (range, 19-84). The occlusion rate after 2 years was 94.5%. Clinical outcomes of CEAP score, VCSS, and QoL scores improved significantly from 2.15 ± 0.45, 2.70 ± 2.04, and 6.91 ± 6.69 at baseline to 2.10 ± 0.32, 0.63 ± 0.04, and 3.38 ± 4.74 at the study end, respectively. The preoperative and postoperative differences in CEAP score for unilateral and bilateral RFA were 0.02 ± 0.21 and 0.13 ± 0.49, respectively (p = .073). Those of VCSS for unilateral and bilateral RFA were 1.87 ± 1.50 and 4.01 ± 2.93, respectively (p < .001). CONCLUSION: Good clinical outcomes were shown after RFA with respect to CEAP, VCSS, and QoL scores. The simultaneous bilateral RFA can be performed with effectiveness.