A small-molecule inhibitor of SMAD3 attenuates resistance to anti-HER2 drugs in HER2-positive breast cancer cells.

PURPOSE: Resistance against anti-HER2 drugs in HER2-positive breast cancer is a major obstacle to the improving prognosis. Transforming growth factor ß (TGFß) is a cytokine involved in the acquisition of more malignant phenotypes through epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. The aim of this study was to investigate the effects of TGFß and its downstream SMAD pathway on resistance to anti-HER2 drugs. METHODS: HER2-positive breast cancer cell lines were stimulated with TGFß for 14 days. Then, the sensitivity to trastuzumab and lapatinib and the expression levels of various EMT and CSC markers were examined. The correlation of nuclear SMAD3 expression in untreated breast tumor tissues with trastuzumab efficacy in neoadjuvant settings was examined. The effect of a small-molecule inhibitor of SMAD3 (SIS3) on resistance to anti-HER2 drugs was explored. RESULTS: We found that continuous activation of the TGFß-SMAD3 pathway induced resistance to anti-HER2 drugs and CSC traits in HER2-positive breast cancer cells. The induction of drug resistance by TGFß required strong activation of SMAD3. In fact, activated SMAD3 regulated multiple genes that harbor SMAD-binding elements and are involved in trastuzumab resistance. Nuclear SMAD3 expression in tumor tissue was inversely correlated with sensitivity to neoadjuvant treatment with trastuzumab. SIS3 not only prevented the acquisition of resistance to anti-HER2 drugs but also restored trastuzumab sensitivity in trastuzumab-resistant cells. CONCLUSIONS: This study indicates that the TGFß-SMAD3 pathway plays an important role in the induction and maintenance of resistance to anti-HER2 drugs. Thus, SMAD3 is a potential therapeutic target that can inhibit resistance and restore sensitivity to anti-HER2 drugs.

[Local Control of Advanced Breast Cancer with Giant Ulcer].

This study reports the treatment and local control of advanced breast cancer with a giant ulcer. A 53-year-old woman presented with a large left breast tumor and an associated giant ulcer, with massive exudates, bleeding, and an offensive odor. Histopathological examination revealed an invasive ductal carcinoma(Luminal B type). Computed tomography(CT) showed multiple metastases to the lymph nodes, lungs, liver and bones. The patient received chemotherapy with a combina- tion of paclitaxel(PTX 90mg/m / 2)and bevacizumab(BEV 10 mg/kg). After 4 courses of chemotherapy, there was a significant reduction in the tumor size, the discharge of exudates and bleeding as well as lumbago and femoral pain. High CEA and CA15-3 levels had been normalized and CT showed a remarkable decrease in metastases. Compared to the tumor itself, the ulcer associated with it had shown a smaller decrease in size, and there was the possibility of perforation in the thin chest wall. Suspecting these outcomes to the adverse events of BEV, its use was discontinued, and starting with course 5 of chemothera- py, we administrated only PTX(90mg/m2). Subsequently, the ulcer showed obvious granulation and was infected. CT of the chest prior to the second course of PTX revealed pleurisy, pneumonia and atelectasis. Following the administration of antibiotics, while infection in the ulcer had subsided, pleurisy and pneumonia continued, with increased right pleural effusion, which finally required drainage. We had to discontinue the administration of PTX. BEV, although effective as first-line therapy, has the adverse effect of slowing wound healing. Therefore, even though the combination therapy of BEV and PTX is markedly effective for systemic therapy, it should be altered for local wound healing as in this case.

Protective effect of naturally occurring anti-HER2 autoantibodies on breast cancer.

Anti-HER2-autoantibodies (HER2-AAbs) are found in breast cancer patients as well as healthy individuals. However, the clinical relevance of the antibodies is unknown. We established an enzyme-linked immunosorbent assay with high sensitivity and quantified serum HER2-AAbs in 100 healthy women, 100 untreated patients with ductal carcinoma in situ (DCIS), and 500 untreated patients with invasive breast carcinoma (IBC). The associations between the levels of HER2-AAbs and breast cancer risk, and recurrence-free survival, were examined. High levels of HER2-AAbs were significantly associated with a reduced risk of DCIS (odds ratio [OR] 0.19, P = 4.6 × 10(-7)) or IBC (OR 0.31, P = 3.7 × 10(-7)). Subgroup analysis of IBC revealed a stronger association of HER2-AAbs with a reduced risk of the hormone receptor (HR)(-)/HER2(+) subtype (OR 0.12) than the other subtypes (HR(+)/HER2(-) [OR = 0.32], HR(+)/HER2(+) [OR 0.38], and HR(-)/HER2(-) [OR 0.29]). When we set the cutoff of HER2-AAbs at 20 ng/mL, recurrence-free survival of HER2-AAb-positive patients (N = 74) was significantly better than that of HER2-AAb-negative patients (N = 426) (P = 0.015). Univariate and multivariate analyses demonstrated that HER2-AAbs, as well as histological grade, were independently and significantly (P = 0.0065 and 0.049, respectively) associated with recurrence-free survival. Our exploratory study suggests a protective effect of naturally occurring HER2-AAbs on the development of primary and recurrent breast cancer. Further studies on HER2-AAbs are warranted.

One-Step Nucleic Acid Amplification Assay for Detection of Axillary Lymph Node Metastases in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy.

BACKGROUND: The accuracy of one-step nucleic acid amplification (OSNA) for the detection of lymph node (LN) metastasis in breast cancer patients has been well established. This study aimed to evaluate its accuracy for patients treated with neoadjuvant chemotherapy (NAC). METHODS: For this study, 300 LNs, 115 sentinel lymph nodes (SLNs), and 185 non-SLNs from 88 breast cancer patients treated with NAC were examined by means of histology (hematoxylin and eosin staining and pancytokeratin immunostaining) and OSNA. RESULTS: The diagnostic accuracy, sensitivity, and specificity of OSNA were respectively 92.3, 88.5, and 93.3 % for all LNs, and the corresponding values were 87.8, 75.0, and 91.2 % for SLNs and 95.1, 97.3, and 94.6 % for non-SLNs. The diagnostic accuracy of OSNA was significantly lower for SLNs than for non-SLNs (P = 0.021), which was attributable to the low sensitivity for detection of micrometastases (micromets) due to lower CK19 mRNA expression detected by in situ hybridization (ISH) in SLN micromets than in non-SLN micromets. For primary breast tumors, CK19 mRNA expression showed a significant reduction after NAC (P = 0.040). CONCLUSIONS: The diagnostic accuracy of OSNA for NAC-treated patients is similar to that for NAC-nontreated patients, but its accuracy is significantly lower for SLNs than for non-SLNs. The findings obtained with CK19 mRNA ISH suggest that most SLN micromets cannot be detected by OSNA due to the reduced expression of CK19 mRNA induced by NAC.

A lower volume culture method for obtaining a larger yield of neuron-like cells from mesenchymal stem cells.

Mesenchymal stem cells (MSCs) represent a promising cell source for stem cell therapy to replace neurons damaged by neurodegenerative diseases. A system designed for in vitro neuronal differentiation of MSCs is an indispensable technique, which provides MSC-derived functional neurons for cell-replacement therapies and valuable information in pre-clinical research. This study investigated the effects of reducing the volume of neural induction medium on cell viability and neural differentiation of MSCs. When MSCs were differentiated in low volumes of neural induction medium, rather than using the conventional method, the cell density on culture dishes significantly increased. The % cell death, including apoptosis and necrosis, was significantly lower in the lower volume method than in the conventional method. There were no significant differences between the lower volume and conventional methods in the expression levels of the neuronal marker genes. In an analysis of immunostaining for a mature neuronal marker, no significant difference was detected between the media volumes. These findings demonstrate that neuronal induction of MSCs in low volumes of differentiation medium promoted survival during differentiation and resulted in larger numbers of MSC-derived neurons, compared to the conventional method. This novel lower volume method offers both financial and cell-yield advantages over the conventional method.

Mutational analysis of MED12 in fibroadenomas and phyllodes tumors of the breast by means of targeted next-generation sequencing.

We aimed to analyze MED12 mutation in fibroadenomas (FAs) and phyllodes tumors (PTs) of the breast, which are closely related and consist of epithelial and stromal components. Targeted deep-sequencing using next-generation sequencing was performed in FAs (n = 58) and PTs (n = 27). The frequency of MED12 mutant tumors was significantly higher (P = 0.016) in PTs (74.1 %) than in FAs. (46.6 %). As for FAs, this frequency was significantly higher (P = 0.001) for intracanalicular type (69.0 %) than for other histological subtypes such as pericanalicular, organoid, and mastopathic types (24.1 %). Laser microdissection study revealed that stromal cells, but not epithelial cells, harbored MED12 mutations in both FAs and PTs. MED12 mutation is implicated in the pathogenesis of both FAs and PTs. The similarly high frequency of MED12 mutation in intracanalicular type FAs suggests that they are most closely related to PTs. It is thus speculated that FAs with MED12 mutation are more likely to progress to PTs.

PIK3CA mutations in serum DNA are predictive of recurrence in primary breast cancer patients.

We attempted to develop a highly sensitive and specific method for the detection of circulating tumor DNA (ctDNA) using a digital PCR (dPCR) assay for PIK3CA mutations (i.e., H1047R, E545K, and E542K) in primary breast cancer patients. The sensitivity of the dPCR assay for the mutant alleles was examined using cell lines with PIK3CA mutations and proved to be 0.01 %. Serum samples were collected pre-operatively from 313 stage I-III breast cancer patients, of whom 110 were found to have PIK3CA mutant tumors. The serum samples from these patients with PIK3CA mutant tumors were subjected to the dPCR assay, and 25 (22.7 %) were found to be positive. No PIK3CA mutant ctDNA was detected in the serum samples of 50 healthy women and 30 breast cancer patients with PIK3CA non-mutant tumors. The patients with PIK3CA mutant ctDNA were dichotomized into mutant ctDNA-high (ctDNA(high)) and ctDNA-low (ctDNA(low)) groups based on the median. The ctDNA(high) patients exhibited significantly shorter recurrence-free survival (RFS; P = 0.0002) and overall survival rates (OS; P = 0.0048) compared to those exhibited by the combined ctDNA(low) patient and ctDNA-free patient group. Multivariate analysis revealed that ctDNA(high) status significantly predicted poor RFS and OS and did so independently of conventional histological parameters. These results suggest that dPCR is a highly sensitive and specific method for the detection of PIK3CA mutant ctDNA and that ctDNA(high) but not ctDNA(low) status is a significant and independent prognostic factor for primary breast cancer patients.

Comparison of efficacy of 95-gene and 21-gene classifier (Oncotype DX) for prediction of recurrence in ER-positive and node-negative breast cancer patients.

We recently developed a 95-gene classifier (95(GC)) for the prognostic prediction for ER-positive and node-negative breast cancer patients treated with only adjuvant hormonal therapy. The aim of this study was to validate the efficacy of 95(GC) and compare it with that of 21(GC) (Oncotype DX) as well as to evaluate the combination of 95(GC) and 21(GC). DNA microarray data (gene expression) of ER-positive and node-negative breast cancer patients (n = 459) treated with adjuvant hormone therapy alone as well as those of ER-positive breast cancer patients treated with neoadjuvant chemotherapy (n = 359) were classified with 95(GC) and 21(GC) (Recurrence Online at http://www.recurrenceonline.com/ ). 95(GC) classified the 459 patients into low-risk (n = 285; 10 year relapse-free survival: 88.8 %) and high-risk groups (n = 174; 70.6 %) (P = 5.5e-10), and 21(GC) into low-risk group (n = 286; 89.3 %), intermediate-risk (n = 81; 75.7 %), and high-risk (n = 92; 64.7 %) groups (P = 2.9e-10). The combination of 95(GC) and 21(GC) classified them into low-risk (n = 324; 88.9 %) and high-risk (n = 135; 65.0 %) groups (P = 5.9e-14), and also showed that pathological complete response rates were significantly (P = 2.5e-6) higher for the high-risk (17.9 %) than the low-risk group (3.6 %). In addition, we demonstrated that 95(GC) was calculated on a single-sample basis if the reference robust multi-array average workflow was used for normalization. The prognostic prediction capability of 95(GC) appears to be comparable to that of 21(GC). Moreover, their combination seems to result in the identification of more low-risk patients who do not need chemotherapy than either classification alone. The patients in the high-risk group were found to be more chemo-sensitive so that they can benefit more from adjuvant chemotherapy.

Clinicopathological analysis of breast ductal carcinoma in situ with ALDH1-positive cancer stem cells.

OBJECTIVE: The aim of this study was to elucidate the clinicopathological characteristics of breast ductal carcinomas in situ (DCIS) with aldehyde dehydrogenase 1 (ALDH1)-positive cancer stem cells (CSCs). METHODS: DCIS (n = 194) were subjected to immunohistochemical staining and results were examined for associations with various clinicopathological parameters. The ALDEFLUOR assay for breast cancer cell lines was also performed to determine the proportion of CSCs according to intrinsic subtype. RESULTS: DCIS with ALDH1-positive CSCs were significantly (p < 0.05) more likely to be estrogen receptor-α (ER)-negative, progesterone receptor (PgR)-negative, Ki67-positive and HER2-positive tumors. Luminal A subtype (8.6%) showed a significantly (p < 0.001) lower ALDH1 positivity than the other subtypes [luminal B (50.0%), luminal HER2 (36.8%), HER2 (35.3%) and triple-negative subtype (26.7%)]. Double immunostaining revealed that ALDH1-positive CSCs did not overlap with ER-, PgR- or Ki67-positive tumor cells but did overlap with HER2-positive tumor cells. The percentage of ALDEFLUOR-positive CSCs was lower in the luminal A cell lines (0.02% for T-47D and 0.4% for MCF7) than in the luminal HER2 (9.1% for BT-474 and 9.5% for MDA-MB-361), HER2 (13.9% for AU565 and 33.2% for SK-BR-3) and triple-negative cell lines (28.4% for MDA-MB-231 and 30.7% for MDA-MB-468). CONCLUSIONS: Our results suggest that most CSCs in DCIS are in the G0 phase (Ki67 negative) and do not express ER or PgR, but they do express HER2 in HER2-positive tumors.

Identification of DNA-dependent protein kinase catalytic subunit as a novel interaction partner of lymphocyte enhancer factor 1.

Lymphocyte enhancer factor 1 (LEF1), a member of the LEF/T-cell-specific factor (TCF) family of the high mobility group domain transcription factors, acts downstream in canonical Wnt signaling. Aberrant transactivation of LEF1 contributes to the tumorigenesis of colonic neoplasms, sebaceous skin tumors, and lymphoblastic leukemia. LEF1-associated proteins are crucial for regulating its transcriptional activity. In this study, glutathione-S-transferase pull-down assay and mass spectrometry enabled identification of the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) as a novel interaction partner for LEF1. The interaction between LEF1 and DNA-PKcs was confirmed using in vivo co-immunoprecipitation. Furthermore, double immunofluorescence observations showed that LEF1 and DNA-PKcs colocalized in the nuclei of colon adenocarcinoma cell lines. Identification of the interaction between LEF1 and DNA-PKcs may provide clues for a novel therapy for cancer treatment as well as for understanding LEF1-mediated transcriptional regulation.

GSTP1 expression predicts poor pathological complete response to neoadjuvant chemotherapy in ER-negative breast cancer.

The purpose of the present study was to investigate the association of glutathione S-transferase P1 (GSTP1) expression with resistance to neoadjuvant paclitaxel followed by 5-fluorouracil/epirubicin/cyclophosphamide (P-FEC) in human breast cancers. The relationship of GSTP1 expression and GSTP1 promoter hypermethylation with intrinsic subtypes was also investigated. In this study, primary breast cancer patients (n = 123, stage II-III) treated with neoadjuvant P-FEC were analyzed. Tumor samples were obtained by vacuum-assisted core biopsy before P-FEC. GSTP1 expression was determined using immunohistochemistry, GSTP1 promoter methylation index (MI) using bisulfite methylation assay and intrinsic subtypes using DNA microarray. The pathological complete response (pCR) rate was significantly higher in GSTP1-negative tumors (80.0%) than GSTP1-positive tumors (30.6%) (P = 0.009) among estrogen receptor (ER)-negative tumors but not among ER-positive tumors (P = 0.267). Multivariate analysis showed that GSTP1 was the only predictive factor for pCR (P = 0.013) among ER-negative tumors. Luminal A, luminal B and HER2-enriched tumors showed a significantly lower GSTP1 positivity than basal-like tumors (P = 0.002, P < 0.001 and P = 0.009, respectively), while luminal A, luminal B and HER2-enriched tumors showed a higher GSTP1 MI than basal-like tumors (P = 0.076, P < 0.001 and P < 0.001, respectively). In conclusion, these results suggest the possibility that GSTP1 expression can predict pathological response to P-FEC in ER-negative tumors but not in ER-positive tumors. Additionally, GSTP1 promoter hypermethylation might be implicated more importantly in the pathogenesis of luminal A, luminal B and HER2-enriched tumors than basal-like tumors.

MDM2 SNP309 and TP53 R72P associated with severe and febrile neutropenia in breast cancer patients treated with 5-FU/epirubicin/cyclophosphamide.

The aim of this study was to investigate the association of two genetic polymorphisms, MDM2 SNP309 and TP53 R72P, with incidence of neutropenia in breast cancer patients treated with 5-FU/epirubicin/cyclophosphamide (FEC). Primary breast cancer patients (n = 216) treated with adjuvant FEC (60, 75 or 100 mg/m(2)) were included in this study. The association of genotypes of MDM2 SNP309 and TP53 R72P, determined by TaqMan SNP Genotyping Assays, with febrile neutropenia (FN) was investigated. In the patients treated with FEC100, G/G genotype for MDM2 SNP309 (G/G genotype( MDM2 )) was significantly (P < 0.01) associated with a lower incidence (5.3 vs. 39.2%) of severe neutropenia (<100/mm(3)) than with T/T + T/G genotypes( MDM2 ), and C/C genotype for TP53 R72P (C/C genotype( TP53 )) was significantly (P = 0.03) associated with a higher incidence (58.3 vs. 27.3%) of FN than with G/G + G/C genotypes( TP53 ). The combination of C/C genotype( TP53 ) and T/T + T/G genotype( MDM2 ) showed the highest risk for developing severe neutropenia (83.3%) and FN (62.5%) than any other combinations. In the patients treated with FEC60 or FEC75, there was no significant association of MDM2 SNP309 and TP53 R72P with severe neutropenia and FN. MDM2 SNP309 and TP53 R72P are significantly associated with severe neutropenia and FN, respectively, in breast cancer patients treated with FEC100, and especially their combination may be a useful predictor of severe neutropenia and FN.

Intratumoral regulatory T cells as an independent predictive factor for pathological complete response to neoadjuvant paclitaxel followed by 5-FU/epirubicin/cyclophosphamide in breast cancer patients.

Anti-tumor immunity is thought to play a significant role in chemotherapeutic response of breast tumors. In the present study, we investigated whether tumor infiltrating FOXP3+ regulatory T cells, CD8+ cytotoxic T cells, and IL17F+ helper T cells were associated with a pathological complete response (pCR) to neoadjuvant chemotherapy (NAC). Breast cancer patients (stages II and III, n = 180) who were treated with NAC consisting of sequential weekly paclitaxel followed by 5-FU/epirubicin/cyclophosphamide were included for this study. Core needle tumor specimens obtained before NAC were immunohistochemically examined for FOXP3, CD8, and IL17F. Intratumoral infiltration of FOXP3+, CD8+, and IL17F+ T cells was observed in 62.2, 80.0, and 62.2 % of tumors, respectively. FOXP3 and CD8 infiltrates, but not IL17F infiltrate, were significantly (P < 0.001 and P = 0.007, respectively) associated with a high-pCR rate (31.3 and 25.7 %, respectively), and breast tumors with both FOXP3 and CD8 infiltrates showed the highest pCR rate (33.0 %). Multivariate analysis indicated that only FOXP3 infiltrates (P = 0.014) and the conventional predictive factor Ki67 (P = 0.031) were statistically significant and independent predictors of pCR. Breast tumors with FOXP3 and CD8 infiltrates were more likely to achieve pCR. FOXP3 infiltrate, in combination with Ki67, could thus be used as a clinically useful predictor of response to NAC. The possible indirect mechanism through which chemotherapy exerts its anti-tumor activity, i.e., enhancing anti-tumor immunity by inhibiting FOXP3, was also suggested.

14-3-3σ expression is associated with poor pathological complete response to neoadjuvant chemotherapy in human breast cancers.

14-3-3σ is a tumor suppressor gene induced by p53 in response to DNA damage and reportedly associated with resistance to chemotherapy. The aim of this study was to investigate whether 14-3-3σ expression is also associated with resistance to neoadjuvant chemotherapy consisting of paclitaxel followed by 5-FU/epirubicin/cyclophosphamide (P-FEC) in human breast cancer patients. A total of 123 primary breast cancer patients treated with neoadjuvant chemotherapy (P-FEC) were included in this study. Immunohistochemistry of 14-3-3σ and p53 as well as direct sequencing of TP53 were performed using the tumor biopsy samples obtained prior to neoadjuvant chemotherapy. Thirty-eight of the tumors (31%) were positive for 14-3-3σ. There was no significant association between 14-3-3σ expression and TP53 mutation or p53 expression. However, 14-3-3σ expression showed a significantly (P=0.009) negative association with pathological complete response (pCR) to P-FEC, and multivariate analysis demonstrated that only 14-3-3σ (P=0.015) and estrogen receptor (P=0.021) were significantly and independently associated with pCR. The combination of 14-3-3σ expression and TP53 mutation status had an additive negative effect on pCR, i.e., pCR rates were 45.5% for 14-3-3σ negative/TP53 mutant tumors, 24.6% for 14-3-3σ negative/TP53 wild tumors, 23.1% for 14-3-3σ positive/TP53 mutant tumors, and 0% for 14-3-3σ positive/TP53 wild tumors. These results demonstrate that 14-3-3σ expression is significantly associated with resistance to P-FEC and this association is independent of other biological markers. The combination of 14-3-3σ expression and TP53 mutation status has an additively negative effect on the response to P-FEC.

Wnt signaling promotes neuronal differentiation from mesenchymal stem cells through activation of Tlx3.

Wnt/ß-catenin signaling promotes neural differentiation by activation of the neuron-specific transcription factors, Neurogenin1 (Ngn1), NeuroD, and Brn3a, in the nervous system. As neurons in cranial sensory ganglia and dorsal root ganglia transiently express Ngn1, NeuroD, and Brn3a during embryonic development, we hypothesized that Wnt proteins could instructively promote a sensory neuronal fate from mesenchymal stem cells (MSCs) directed to differentiate into neurons. Consistent with our hypothesis, Wnt1 induced expression of sensory neuron markers including Ngn1, NeuroD, and Brn3a, as well as glutamatergic markers in neurally induced MSCs in vitro and promoted engraftment of transplanted MSCs in the inner ear bearing selective loss of sensory neurons in vivo. Given the consensus function of T-cell leukemia 3 (Tlx3), as a glutamatergic selector gene, we postulated that the effects of canonical Wnt signaling on sensory neuron and glutamatergic marker gene expression in MSCs may be mediated by Tlx3. We first confirmed that Wnt1 indeed upregulates Tlx3 expression, which can be suppressed by canonical Wnt inhibitors. Next, our chromatin immunoprecipitation assays revealed that T-cell factor 3/4, Wnt-activated DNA binding proteins, interact with a regulatory region of Tlx3 in MSCs after neural induction. Furthermore, we demonstrated that forced expression of Tlx3 in MSCs induced sensory and glutamatergic neuron markers after neural induction. Together, these results identify Tlx3 as a novel target for canonical Wnt signaling that confers somatic stem cells with a sensory neuron phenotype upon neural induction.

Methylated DNA and total DNA in serum detected by one-step methylation-specific PCR is predictive of poor prognosis for breast cancer patients.

PURPOSE: We recently developed the one-step methylation-specific PCR (OS-MSP) assay which can detect methylated DNA (met-DNA) in serum with high sensitivity. To examine its prognostic value, we applied this new assay to the detection of met-DNA in serum of breast cancer patients. METHODS: Serum samples taken before surgery from 336 primary invasive breast cancer patients were subjected to the OS-MSP assay for the promoter regions of GSTP1, RASSF1A, and RARß2. The assay outcome was considered positive when methylation was detected in at least one of these three genes. Total DNA content in serum was also determined. RESULTS: Of the 336 stage I/II patients, 33 (10%) were positive for met-DNA in serum and showed a significantly worse overall survival (OS) rate at 100 months (78 vs. 95%; p = 0.002) than those with negative findings (n = 303). Patients with high total DNA in serum (n = 112) also showed a significantly worse OS rate at 100 months (86 vs. 97%; p = 0.001) than those with low total DNA in serum (n = 224). Moreover, patients both positive for met-DNA and with high total DNA in serum (n = 18) showed a much worse OS rate at 100 months (65 vs. 94%; p < 0.001) than the others (n = 318). CONCLUSIONS: Met-DNA in serum detected with the OS-MSP assay constitutes a significant and independent prognostic factor, and its combination with total DNA in serum seems to be even more effective for prediction of prognosis for breast cancer patients.

Some fine-structural findings on the thyroid gland in Apc1638T/1638T mice that express a C-terminus lacking truncated Apc.

Adenomatous polyposis coli (Apc) is a multifunctional protein as well as a tumor suppressor. To determine the functions of the C-terminal domain of Apc, we examined Apc(1638T/1638T) mice that express a truncated Apc lacking the C-terminal domain. The Apc(1638T/1638T) mice were tumor free and exhibited growth retardation. We recently reported abnormalities in thyroid morphology and functions of Apc(1638T/1638T) mice, although the mechanisms underlying these abnormalities are not known. In the present study, we further compared thyroid gland morphology in Apc(1638T/1638T) and Apc(+/+) mice. The diameters of thyroid follicles in the left and right lobes of the same thyroid gland of Apc(1638T/1638T) mice were significantly different whereas the Apc(+/+) mice showed no significant differences in thyroid follicle diameter between these lobes. To assess the secretory activities of thyroid follicular cells, we performed double-immunostaining of thyroglobulin, a major secretory protein of these cells, and the rough endoplasmic reticulum (rER) marker calreticulin. In the Apc(1638T/1638T) follicular epithelial cells, thyroglobulin was mostly colocalized with calreticulin whereas in the Apc(+/+) follicular epithelial cells, a significant amount of the cytoplasmic thyroglobulin did not colocalize with calreticulin. In addition, in thyroid-stimulating hormone (TSH)-treated Apc(1638T/1638T) mice, electron microscopic analysis indicated less frequent pseudopod formation at the apical surface of the thyroid follicular cells than in Apc(+/+) mice, indicating that reuptake of colloid droplets containing iodized thyroglobulin is less active. These results imply defects in intracellular thyroglobulin transport and in pseudopod formation in the follicular epithelial cells of Apc(1638T/1638T) mice and suggest suppressed secretory activities of these cells.

The C-terminal domain of the adenomatous polyposis coli (Apc) protein is involved in thyroid morphogenesis and function.

Adenomatous polyposis coli (APC) is a multifunctional protein as well as a tumor suppressor. To determine the functions of the C-terminal domain of Apc, we have investigated Apc ( 1638T/1638T ) mice, which express a truncated Apc that lacks the C-terminal domain. Apc ( 1638T/1638T ) mice are tumor free and exhibit growth retardation. In the present study, we analyzed the morphology and functions of the thyroid gland in Apc ( 1638T/1638T ) mice. There was no significant difference in the basal concentration of serum thyroid hormones between Apc ( 1638T/1638T ) and Apc (+/+) mice. Thyroid follicle size was significantly larger in Apc ( 1638T/1638T ) mice than in Apc (+/+) mice. The extent of serum T4 elevation following exogenous thyroid-stimulating hormone (TSH) injection was lower in Apc ( 1638T/1638T ) mice than in Apc (+/+) mice. TSH also induced a greater reduction in thyroid follicle size in Apc ( 1638T/1638T ) mice than in Apc (+/+) mice. Analyses using immunohistochemistry and electron microscopy indicated that follicular epithelial cells in Apc ( 1638T/1638T ) mice had an enlarged rough endoplasmic reticulum of irregular shape. These results suggest that the C-terminal domain of Apc is involved in thyroid morphology and function.

The histone demethylase LSD1 regulates inner ear progenitor differentiation through interactions with Pax2 and the NuRD repressor complex.

The histone demethylase LSD1 plays a pivotal role in cellular differentiation, particularly in silencing lineage-specific genes. However, little is known about how LSD1 regulates neurosensory differentiation in the inner ear. Here we show that LSD1 interacts directly with the transcription factor Pax2 to form the NuRD co-repressor complex at the Pax2 target gene loci in a mouse otic neuronal progenitor cell line (VOT-N33). VOT-N33 cells expressing a Pax2-response element reporter were GFP-negative when untreated, but became GFP positive after forced differentiation or treatment with a potent LSD inhibitor. Pharmacological inhibition of LSD1 activity resulted in the enrichment of mono- and di-methylation of H3K4, upregulation of sensory neuronal genes and an increase in the number of sensory neurons in mouse inner ear organoids. Together, these results identify the LSD1/NuRD complex as a previously unrecognized modulator for Pax2-mediated neuronal differentiation in the inner ear.

LATS2 promoter hypermethylation and its effect on gene expression in human breast cancer.

Tumor-specific promoter hypermethylation of large tumor suppressor, homolog 2 (LATS2), a tumor suppressor gene, has been investigated using methylation-specific polymerase chain reaction (MSP) assays in different types of human cancer producing conflicting results. The aim of the present study was to evaluate the methylation status of the LATS2 promoter region using bisulfite sequencing with a next generation sequencer for breast cancer. In the 11 patients enrolled in the present study, the LATS2 promoter methylation index (MI) was uniformly high in tumor and normal tissues of the breast (median, 84.0 and 87.4%, respectively). The presence of LATS2 promoter hypermethylation was confirmed in isolated tumor cells and normal epithelial cells using the magnetic-activated cell sorting method. In situ hybridization for LATS2 messenger RNA (mRNA) revealed that the mRNA expression of LATS2 was higher in normal epithelial cells, compared with tumor cells, however, it was not significantly associated with LATS2 MI. In 12 breast cancer cell (BCC) lines and two normal breast cell lines, the LATS2 promoter was uniformly hypermethylated with no correlation between the mRNA expression of LATS2 and the LATS2 MI. In addition, treatment of the BCC lines with a demethylating reagent had minimal effect on the mRNA expression of LATS2 in any of these cell lines. These results demonstrated that LATS2 hypermethylation was not involved in silencing the mRNA expression of LATS2 mRNA. The lower mRNA expression level of LATS2 in tumor cells, compared with normal epithelial cells, suggested the possible involvement of downregulation in the mRNA expression of LATS2 in the pathogenesis of breast cancer. Therefore, the conflicting results previously reported for LATS2 promoter methylation in different types of cancer, detected using MSP assays may be attributable to the low fidelity of the MSP assay.