Modular Design Platform for Activatable Fluorescence Probes Targeting Carboxypeptidases Based on ProTide Chemistry

Carboxypeptidases (CPs) are a family of hydrolases that cleave one or more amino acids from the C-terminal of peptides or proteins and play indispensable roles in various physiological and pathological processes. However, only a few highly activatable fluorescence probes for CPs have been reported, and there is a need for a flexibly tunable molecular design platform to afford a range of fluorescence probes for CPs for biological and medical research. Here, we focused on the unique activation mechanism of ProTide-based prodrugs and established a modular design platform for CP-targeting florescence probes based on ProTide chemistry. In this design, probe properties such as fluorescence emission wavelength, reactivity/stability, and target CP can be readily tuned and optimized by changing the four probe modules: the fluorophore, the substituent on the phosphorus atom, the linker amino acid at the P1 position, and the substrate amino acid at the P1' position. In particular, switching the linker amino acid at position P1 enabled us to precisely optimize the reactivity for target CPs. As a proof-of-concept, we constructed probes for carboxypeptidase M (CPM) and prostate-specific membrane antigen (also known as glutamate carboxypeptidase II). The developed probes were applicable for the imaging of CP activities in live cells and in clinical specimens from patients. This design strategy should be useful in studying CP-related biological and pathological phenomena.

Dynamic Changes in Peripheral Systemic Immunity Markers During Chemotherapy in HER2-negative Advanced Breast Cancer

BACKGROUND/AIM

The immune system has a pivotal role in modulating the response to chemotherapy in breast cancer (BC). However, the immune status during chemotherapy remains unclear. We evaluated the sequential changes in peripheral systemic immunity markers in BC patients treated with various chemotherapeutic agents.

MATERIALS AND METHODS

We examined the correlation between the peripheral systemic immunity markers, neutrophil-to-lymphocyte ratio (NLR), absolute lymphocyte count (ALC) and the local cytolytic activity (CYT) score obtained by quantitative reverse-transcription polymerase chain reaction of 84 preoperative BC patients. Next, we observed the sequential changes in the peripheral systemic immunity markers during treatment with four anticancer drugs: oral 5-fluorouracil derivative; S-1, epirubicin plus cyclophosphamide; paclitaxel plus the anti-vascular endothelial growth factor antibody bevacizumab, and eribulin in 172 HER2-negative advanced BC patients. Finally, we examined the correlation between the changes in the peripheral systemic immunity markers, time to treatment failure (TTF) and progression-free survival (PFS).

RESULTS

A negative correlation was found between ALC and NLR. ALC-low and NLR-high cases were positively associated with CYT score-low cases. The ratio of ALC-increase and NLR-decrease varies depending on the anticancer drugs used. The responder group (TTF ≥3 months) had a higher NLR-decrease ratio than the nonresponder group (TTF <3 months). Patients with a high NLR-decrease ratio showed higher PFS.

CONCLUSION

The change in ALC or NLR varies according to the anticancer drugs, suggesting differential immunomodulatory effects of the drugs. Furthermore, the change in NLR reflects the therapeutic efficacy of chemotherapy in advanced BC.

[Efficacy and Safety of Scalp Cooling Device RV21-01 for Suppression of Chemotherapy-Induced Alopecia in Breast Cancer Patients]

We evaluated the efficacy and safety of the RV21-01 scalp cooling device in controlling hair loss during chemotherapy in this study. Thirty-nine breast cancer patients who underwent anthracycline- and/or taxane-based chemotherapy were assigned to the scalp cooling group(27 patients)and the hair loss observation group(12 patients). The alopecia rate using the NCI alopecia toxicity criteria and the quantitative alopecia toxicity grade was 51.9%(14/27 patients)and 100%(12/12 patients)in the scalp cooling and hair loss observation groups, respectively. Regarding safety, all subjects in both the scalp cooling and hair loss observation groups experienced adverse events; only 1 subject in each group experienced a severe adverse event due to chemotherapy and majority of the subjects in both groups experienced minor adverse events. RV21-01 scalp cooling therapy was demonstrated to be effective in reducing hair loss in patients undergoing standard chemotherapy for breast cancer. In addition, the adverse events associated with the scalp cooling therapy were minor and mild, and hence, deemed acceptable.

Clinical usefulness of a novel fluorescence technique for the intraoperative diagnosis of surgical margins in patients with breast cancer

In both 5- and 15-min data, FI was significantly higher in malignant tissues than in benign tissues. The diagnostic accuracy was similar at 5 and 15 min. Therefore, the 5-min FI was enough applying in the further analyses.

Rapid and Accurate Visualization of Breast Tumors with a Fluorescent Probe Targeting α-Mannosidase 2C1

Accurate detection of breast tumors and discrimination of tumor from normal tissues during breast-conserving surgery are essential to reduce the risk of misdiagnosis or recurrence. However, existing probes show substantial background signals in normal breast tissues. In this study, we focus on glycosidase activities in breast tumors. We synthesized a series of 12 fluorescent probes and performed imaging-based evaluation on surgically resected human breast specimens. Among them, the α-mannosidase-reactive fluorescent probe HMRef-αMan detected breast cancer with 90% sensitivity and 100% specificity. We identified α-mannosidase 2C1 as the target enzyme and confirmed its overexpression in various breast tumors. We found that fibroadenoma, the most common benign breast lesion in young woman, tends to have higher α-mannosidase 2C1 activity than malignant cancer. Combined application of green-emitting HMRef-αMan and a red-emitting γ-glutamyltranspeptidase probe enabled efficient dual-color, dual-target optical discrimination of malignant and benign tumors.

Erratum to immediate breast volume replacement using a free dermal fat graft after breast cancer surgery: multi-institutional joint research of short-term outcomes in 262 Japanese patients

[This corrects the article on p. 179 in vol. 4, PMID: 26005649.].

Long-term outcome of adipose-derived regenerative cell-enriched autologous fat transplantation for reconstruction after breast-conserving surgery for Japanese women with breast cancer

PURPOSE

More effective methods are needed for breast reconstruction after breast-conserving surgery for breast cancer. The aim of this clinical study was to assess the perioperative and long-term outcomes of adipose-derived regenerative cell (ADRC)-enriched autologous fat grafting.

METHODS

Ten female patients who had undergone breast-conserving surgery and adjuvant radiotherapy for breast cancer were enrolled. An ADRC-enriched fat graft prepared from the patient's adipose tissue was implanted at the time of adipose tissue harvest. The perioperative and long-term outcomes of the grafts, which included safety, efficacy, and questionnaire-based patient satisfaction, were investigated.

RESULTS

The mean operation time was 188 ± 30 min, and the mean duration of postoperative hospitalization was 1.2 ± 0.4 days. No serious postoperative complications were associated with the procedure. Neither recurrence nor metastatic disease was observed during the follow-up period (7.8 ± 1.5 years) after transplantation. Of 9 available patients, "more than or equal to average" satisfaction with breast appearance and overall satisfaction were reported by 6 (66.7%) and 5 (55.6%) patients, respectively.

CONCLUSIONS

ADRC-enriched autologous fat transplantation is thus considered to be safe perioperatively, with no long-term recurrence, for patients with breast cancer treated by breast-conserving surgery, and it may be an option for breast reconstruction, even after adjuvant radiotherapy.

Abstract P4-21-25: The importance of hormone receptor status on biomarker expression and the efficacy of lapatinib plus capecitabine therapy after progression on trastuzumab in HER2 positive recurrent and advanced breast cancer

Background: Anti-HER2 treatment using trastuzumab (Tmab) has contributed to improving the clinical outcome of HER2-positive breast cancerpatients. However, some patients do not respond to Tmab therapy and the combination of Lapatinib and capecitabine (LC) is an effective treatment option after progression on Tmab. Hormone receptor status is also an important factor for deciding if the patient should be treated with endocrine therapy as well. The aim of this study was to investigate the clinical significance of hormone receptor status in biomarker expression and to evaluate the efficacy of lapatinib therapy.

Materials and Methods: Eighty patients with HER2 positive breast cancer refractory to Tmab were enrolled in this prospective trial (KBC-SG 1107) between December 2011 and March 2014. The following treatment began after enrollment; lapatinib 1250-mg tablets were administered orally once daily and capecitabine (2000 mg/m2 per day) on days 1 to 14 every 21 days until disease progression or until severe adverse events. Total HER2 (H2T), p95HER2 (p95), and total HER3 (H3T) expression levels were quantified in formalin-fixed paraffin embedded samples using VeraTag assays. ER and progesterone receptor (PgR), PTEN and p95 expressions were evaluated using immunohistochemistry (IHC) and PIK3CA mutation using direct sequencing. Statistical analyses were performed using SPSS (ver. 21). A two-sided P&lt;0.05 was considered a statistically significant difference.

Results: The ER- and PgR-positive rates were 55.0% and 33.8%, respectively. The response rate to LC was 30% (CR: 1 case; PR: 23 cases), the clinical benefit rate was 51.3% and the median progression-free survival (PFS) was 174.5 days. Both ER and PgR negativity significantly correlated with higher H2T (cutoff: 13.8), p95HER2 (cutoff: 2.8) and PTEN expression levels (cutoff: H score of 100). Lower H2T expression levels and PIK3CA mutation rates were often observed in the non-responders (both: p=0.087). The ER and PgR status did not correlate with response. A high p95 and PTEN expression significantly correlated with longer PFS in ER and/or PgR positive cases (p=0.02 and 0.03), respectively. The overall survival (OS) after LC significantly correlated with the number of recurrence organs (p=0.0002) but not with the p95 and PTEN expression levels.

Conclusion: LC therapy was effective in Tmab-refractory HER2 positive breast cancer. Moreover, the biomarker expression differed depending on the ER/PgR status and a high p95 and PTEN expression correlated with longer PFS in ER and/or PgR positive cases. Further study is necessary to validate these findings.

Citation Format: Arima N, Nishimura R, Toh U, Tanaka M, Saimura M, Okumura Y, Saito T, Tanaka T, Teraoka M, Shimada K, Koga T, Kurashita K, Todoroki H, Ueo H, Ohi Y, Toyoshima S, Mitsuyama S, Tamura K. The importance of hormone receptor status on biomarker expression and the efficacy of lapatinib plus capecitabine therapy after progression on trastuzumab in HER2 positive recurrent and advanced breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-25.

Abstract P5-13-05: The relationship between the expression of FOXA1 and GATA3 and the efficacy of neoadjuvant endocrine therapy

Background.

The estrogen receptor (ER)/ GATA3/ Forkhead box A1 (FOXA1) network is necessary for the ERα functional signature specific to luminal type breast cancers. High expression of FOXA1 indicates a good prognosis in ER-positive breast cancer. However, little is known about the association between the expression of FOXA1 and GATA3, and the efficacy of neoadjuvant endocrine therapy (NAE). This study investigated their predictive potential for NAE and the changes of their expression after NAE.

Methods.

The expression of ER, progesterone receptor (PgR), Ki67, FOXA1, and GATA3 were analyzed by immunohistochemistry in 66 patients with hormone receptor-positive/ human epidermal growth factor receptor 2 (HER2)-negative breast cancer who had been treated with NAE between March 2003 and December 2012 at Kyushu University Hospital, National Kyushu Cancer Center, and Sagara Hospital. The association between the expression of biological marker and the efficacy of NAE, and their expression changes after NAE were evaluated.

Results.

The median age of the patients was 60 years (range, 30–84 years). Pre- and post-menopausal patients were 24 (36.4%) and 42 (63.6%). Endocrine agents that were administered are as follows: aromatase inhibitors (AIs) for 42 patients (63.6%), luteinizing hormone-releasing hormone (LHRH) agonist plus AI for 10 patients (15.2%), LHRH agonist plus tamoxifen for 13 patients (19.7%). NAE yielded a partial response (PR) in 21 patients (31.8%) and stable disease (SD) in 45 patients (68.2%). Breast conserving surgery was performed in 56 patients (84.8%) and mastectomy was performed in 10 patients (15.2%). Preoperative Endocrine Prognostic Index (PEPI) score was 0 in 10 patients (15.2%) and 1 or greater (score 1 ≤) in 56 patients (84.8%).

Pre-treatment FOXA1 expression was positively correlated with GATA3 (P = 0.0003) and PgR (P = 0.0138). Post-treatment Ki67 expression was significantly lower in tumors, which achieved PR compared with those with SD (P = 0.0007). The expression of PgR, Ki67, and FOXA1 was significantly lower in post-treatment tumors compared with those in pre-treatment samples (p &lt; 0.0001, p &lt; 0.0001 and p &lt; 0.0001, respectively). The expression of PgR, Ki67, and FOXA1 was significantly reduced in both tumors with PR and those with SD (PR: P = 0.0004, P &lt; 0.0001, and P = 0.0417, respectively; SD: P &lt; 0.0001, P = 0.0001, and P &lt; 0.0001, respectively). The expression of PgR, Ki67, and FOXA1 was significantly decreased in post-treatment tumors in both patients with the PEPI score 0 and those with score 1 ≤ (score 0: P = 0.0078, P = 0.0059, and P = 0.0098, respectively; score 1 ≤: P &lt; 0.0001, P &lt; 0.0001, and P = 0.0002, respectively). In tumors with PgR &gt; 20%, the expression of Ki67 and FOXA1 were significantly lower in post-treatment tumors (P &lt; 0.0001 and P &lt; 0.0001, respectively).

Conclusions.

FOXA1 expression correlated with PgR expression, and was reduced significantly after NAE. These results suggest that blocking the effect of estrogen might reduce FOXA1 expression.

Citation Format: Tanaka K, Tokunaga E, Inoue Y, Ueo H, Yamashita N, Sagara Y, Ohi Y, Taguchi K, Ohno S, Okano S, Kitao H, Oki E, Oda Y, Maehara Y. The relationship between the expression of FOXA1 and GATA3 and the efficacy of neoadjuvant endocrine therapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-13-05.

Exosomal microRNA in serum is a novel biomarker of recurrence in human colorectal cancer

Background:

Functional microRNAs (miRNAs) in exosomes have been recognised as potential stable biomarkers in cancers. The aim of this study is to identify specific miRNAs in exosome as serum biomarkers for the early detection of recurrence in human colorectal cancer (CRC).

Methods:

Serum samples were sequentially obtained from six patients with and without recurrent CRC. The miRNAs were purified from exosomes, and miRNA microarray analysis was performed. The miRNA expression profiles and copy number aberrations were explored using microarray and array CGH analyses in 124 CRC tissues. Then, we validated exosomal miRNAs in 2 serum sample sets (90 and 209 CRC patients) by quantitative real-time RT–PCR.

Results:

Exosomal miR-17-92a cluster expression level in serum was correlated with the recurrence of CRC. Exosomal miR-19a expression levels in serum were significantly increased in patients with CRC as compared with healthy individuals with gene amplification. The CRC patients with high exosomal miR-19a expression showed poorer prognoses than the low expression group (P<0.001).

Conclusions:

Abundant expression of exosomal miR-19a in serum was identified as a prognostic biomarker for recurrence in CRC patients.

Immediate breast volume replacement using a free dermal fat graft after breast cancer surgery: multi-institutional joint research of short-term outcomes in 262 Japanese patients

BACKGROUND

Immediate volume replacement using a free dermal fat graft (FDFG) has been proven safe with early postoperative benefits. The aims of the present study were to clarify adequate indications and risk factors associated with operative morbidity.

PATIENTS AND METHODS

A multi-institutional analysis of partial mastectomy with immediate volume replacement with FDFG was undertaken in 14 hospitals specializing in breast cancer treatment. Clinical and oncological variables were analyzed to identify factors associated with postoperative complications.

RESULTS

A total of 262 cases were analyzed. Considering the observation period and overlap of patients, 13 (5.4%) out of 242 patients had complications within 1 month of surgery while 7 (4.6%) out of 151 patients developed complications 1-12 months after surgery. Two hundred and eleven out of 242 patients were statistically examined using a multivariate analysis, which revealed that the weight of resected breast tissue, size of implanted FDFG (cranio-caudal length), and weight of implanted FDFG were associated with a higher likelihood of postoperative complications.

CONCLUSIONS

Immediate breast volume replacement using a FDFG after breast cancer surgery should be done for selected patients with breast cancer to avoid postoperative complications. The prospective and larger investigations are warranted for the establishment of appropriate guidelines.

Abstract P3-10-01: Randomized phase III trial of taxanes versus S-1 as first-line chemotherapy for metastatic breast cancer (SELECT BC: CSPOR- MBC01)

Background: Treatment goals of metastatic breast cancer (MBC) are to prolong survival and improve health-related quality of life (HRQOL). Current standard first-line chemotherapy for MBC are the taxanes or anthracyclines; however treatment-related adverse events greatly reduce HRQOL. S-1 is an oral 5-fluorouracil derivative, and phase II trials showed good clinical efficacy and tolerability. We conducted a phase III randomized controlled trial to establish non-inferiority of S-1 in overall survival (OS) and superiority in HRQOL to taxanes, when given as first-line chemotherapy for MBC.

Methods: Patients with HER2-negative non-life-threatening MBC, naïve to chemotherapy for metastatic disease, were randomly assigned to the taxane or S-1 groups. In the taxane group, patients received docetaxel 60-75mg/m2 q3w, paclitaxel 80-100mg/m2 q1w, or paclitaxel 175 mg/m2 q3w according to institutional policy. In the S-1 group, patients received S-1 40–60 mg twice daily based on body surface area using a 28 days on;14 days off regimen. Treatment was repeated until tumor progression or for at least 6 cycles (taxane) or 4 cycles (S-1). After failure of the first-line protocol therapy, another cytotoxic agent was administered, based on the investigator’s discretion. HRQOL was assessed with the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, the Patient Neurotoxicity Questionnaire (PNQ) and the EQ-5D at baseline and 3, 6, 12 months after the start of the treatment. The primary endpoint was OS. Secondary endpoints were time to treatment failure (TTF), adverse events, and HRQOL.

Results: A total of 618 women were enrolled. After a median follow-up of 34.6 months, median OS was 37.2 months in the taxane group (n=309) and 35.0 months in the S-1 group (n=309) (hazard ratio [HR] 1.05, 95% confidence interval [CI] 0.86–1.27, non-inferiority test p=0.015). Median TTF was 8.9 months in the taxane group and 8.0 months in the S-1 group (HR 1.10, 95% CI 0.93–1.30, p=0.022). The incidence of the following grade 3-4 adverse events, allergic reaction, edema and sensory neuropathy, were statistically significantly more frequent in the taxane group (p=0.038, 0.0013 and 0.0077, respectively). Hematologic and non hematologic toxicities except above did not differ significantly between the two groups. The results of the EORTC QLQ-C30 under study treatment indicated that the S-1 was better than the taxanes in global health status/QOL (p=0.044), physical functioning (p=0.002), role functioning (p=0.002), emotional functioning (p=0.004), cognitive functioning (p=0.026), social functioning (p&lt;0.0001), pain (p=0.042) and financial difficulties (p=0.003). EQ-5D utility scores were significantly higher in the S-1 group (p=0.033) during the first year. PNQ sensory and motor scores were significantly better in the S-1 group (p&lt;0.0001 and p=0.0002, respectively).

Conclusions: This study clearly demonstrated that S-1 was superior to taxanes in terms of HRQOL and toxicity, without compromising the prolonged OS. S-1 should be considered as a new standard for first-line chemotherapy for MBC. We are conducting another similar trial (UMIN000005449) that compares first-line anthracycline with S-1 in terms of OS and HRQOL.

Citation Format: Takanori Watanabe, Kojiro Shimozuma, Kentaro Imi, Hiroyoshi Doihara, Hiromitsu Akabane, Hiroaki Ueo, Shinji Ohno, Masahiro Kashiwaba, Atsushi Fukuuchi, Kenichi Watanabe, Michiko Tsuneizumi, Hirotsugu Isaka, Yukari Uemura, Yasuo Ohashi, Hirofumi Mukai. Randomized phase III trial of taxanes versus S-1 as first-line chemotherapy for metastatic breast cancer (SELECT BC: CSPOR- MBC01) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-10-01.

Circulating tumour cell-derived plastin3 is a novel marker for predicting long-term prognosis in patients with breast cancer

BACKGROUND

Identification of promising biomarkers that predict the prognosis of patients with breast cancer is needed. In this study, we hypothesised that the expression of the epithelial-mesenchymal transition-related biomarker plastin3 (PLS3) in peripheral blood could be a prognostic factor in breast cancer.

METHODS

We examined PLS3 expression in breast cancer cell lines with epithelial and mesenchymal traits and in circulating tumour cells (CTCs) obtained from the peripheral blood of breast cancer patients. We investigated PLS3 expression in the peripheral blood of 594 patients with breast cancer to evaluate the clinical significance of PLS3 expression.

RESULTS

Robust PLS3 expression was observed in different breast cancer cell lines (Hs578t, MCF-7, MDA-MB-468, and MDA-MB-231) as well as in a bone marrow derived cancer cell line (BC-M1). In both the training (n=298) and validation (n=296) sets, PLS3 expression was observed in CTCs of patients with breast cancer. PLS3-positive patients showed significantly poorer overall and disease-free survival than PLS3-negative patients (P=0.0001 and 0.003, respectively). Subset analysis revealed that this prognostic biomarker was relevant in patients with stage I-III cancer, particularly in patients with luminal-type and triple-negative-type tumours.

CONCLUSIONS

These data demonstrated that PLS3 was expressed in CTCs undergoing the epithelial-mesenchymal transition in patients with breast cancer. Furthermore, PLS3 may be an excellent biomarker for identifying groups at risk of recurrence or with a poor prognosis.

Identification of a bona fide microRNA biomarker in serum exosomes that predicts hepatocellular carcinoma recurrence after liver transplantation

Background

Predictive biomarkers for the recurrence of hepatocellular carcinoma (HCC) have great benefit in the selection of treatment options, including liver transplantation (LT), for HCC. The purpose of this study was to identify specific microRNAs (miRs) in exosomes from the serum of patients with recurrent HCC and to validate these molecules as novel biomarkers for HCC recurrence.

Methods

We employed microarray-based expression profiling of miRs derived from exosomes in the serum of HCC patients to identify a biomarker that distinguishes between patients with and without HCC recurrence after LT. This was followed by the validation in a separate cohort of 59 HCC patients who underwent living related LT. The functions and potential gene targets of the recurrence-specific miRs were analysed using a database, clinical samples and HCC cell lines.

Results

We found that miR-718 showed significantly different expression in the serum exosomes of HCC cases with recurrence after LT compared with those without recurrence. Decreased expression of miR-718 was associated with HCC tumour aggressiveness in the validated cohort series. We identified HOXB8 as a potential target gene of miR-718, and its upregulation was associated with poor prognosis.

Conclusion

Circulating miRs in serum exosomes have potential as novel biomarkers for predicting HCC recurrence.

F-box protein FBXW7 inhibits cancer metastasis in a non-cell-autonomous manner

The gene encoding F-box protein FBXW7 is frequently mutated in many human cancers. Although most previous studies have focused on the tumor-suppressive capacity of FBXW7 in tumor cells themselves, we determined that FBXW7 in the host microenvironment also suppresses cancer metastasis. Deletion of Fbxw7 in murine BM-derived stromal cells induced accumulation of NOTCH and consequent transcriptional activation of Ccl2. FBXW7-deficient mice exhibited increased serum levels of the chemokine CCL2, which resulted in the recruitment of both monocytic myeloid-derived suppressor cells and macrophages, thereby promoting metastatic tumor growth. Administration of a CCL2 receptor antagonist blocked the enhancement of metastasis in FBXW7-deficient mice. Furthermore, in human breast cancer patients, FBXW7 expression in peripheral blood was associated with serum CCL2 concentration and disease prognosis. Together, these results suggest that FBXW7 antagonizes cancer development in not only a cell-autonomous manner, but also a non-cell-autonomous manner, and that modulation of the FBXW7/NOTCH/CCL2 axis may provide a potential approach to suppression of cancer metastasis.

Diminished expression of MiR-15a is an independent prognostic marker for breast cancer cases

BACKGROUND/AIM

MiR-15a targets Cyclin E1 (CCNE1), which regulates the cell cycle and promotes cell proliferation and progression. Herein, we investigated the clinicopathological significance of miR-15a as a prognostic marker in breast cancer (BC) cases.

MATERIALS AND METHODS

We collected primary tumor samples of 230 BC cases, including 68 triple-negative cases. The expression levels of miR-15a in primary tumors were measured by qRT-PCR assay.

RESULTS

Low expression of miR-15a in primary tumors was significantly correlated with shorter disease-free survival (p=0.0012) and overall survival (p=0.005) compared to the high miR-15a expression in triple-negative BC cases. Multivariate analysis indicated that low miR-15a expression was an independent prognostic factor for overall survival [RR=2.56(1.03-7.18), p=0.04].

CONCLUSION

MiR-15a expression levels could be a promising biological and prognostic marker for overall survival especially in triple-negative BC cases.

Amplification of PVT-1 is involved in poor prognosis via apoptosis inhibition in colorectal cancers

Background:

We previously conducted gene expression microarray analyses to identify novel indicators for colorectal cancer (CRC) metastasis and prognosis from which we identified PVT-1 as a candidate gene. PVT-1, which encodes a long noncoding RNA, mapped to chromosome 8q24 whose copy-number amplification is one of the most frequent events in a wide variety of malignant diseases. However, PVT-1 molecular mechanism of action remains unclear.

Methods:

We conducted cell proliferation and invasion assays using colorectal cancer cell lines transfected with PVT-1siRNA or negative control siRNA. Gene expression microarray analyses on these cell lines were also carried out to investigate the molecular function of PVT-1. Further, we investigated the impact of PVT-1 expression on the prognosis of 164 colorectal cancer patients by qRT–PCR.

Results:

CRC cells transfected with PVT-1 siRNA exhibited significant loss of their proliferation and invasion capabilities. In these cells, the TGF-β signalling pathway and apoptotic signals were significantly activated. In addition, univariate and multivariate analysis revealed that PVT-1 expression level was an independent risk factor for overall survival of colorectal cancer patients.

Conclusion:

PVT-1, which maps to 8q24, generates antiapoptotic activity in CRC, and abnormal expression of PVT-1 was a prognostic indicator for CRC patients.

Vascular endothelial growth factor receptor-1 mRNA overexpression in peripheral blood as a useful prognostic marker in breast cancer

INTRODUCTION

Identification of useful markers associated with poor prognosis in breast cancer patients is critically needed. We previously showed that expression of vascular endothelial growth factor receptor-1 mRNA in peripheral blood may be useful to predict distant metastasis in gastric cancer patients. However, expression of vascular endothelial growth factor receptor-1 mRNA in peripheral blood of breast cancer patients has not yet been studied.

METHODS

Real-time reverse transcriptase-PCR was used to analyze vascular endothelial growth factor receptor-1 mRNA expression status with respect to various clinical parameters in 515 patients with breast cancer and 25 controls.

RESULTS

Expression of vascular endothelial growth factor receptor-1 mRNA in peripheral blood was higher in breast cancer patients than in controls. Increased vascular endothelial growth factor receptor-1 mRNA expression was associated with large tumor size, lymph node metastasis and clinical stage. Patients with high vascular endothelial growth factor receptor-1 mRNA expression also experienced a poorer survival rate than those with low expression levels, including those patients with triple-negative type and luminal-HER2(-) type disease.

CONCLUSIONS

Expression of vascular endothelial growth factor receptor-1 mRNA in peripheral blood may be useful for prediction of poor prognosis in breast cancer, especially in patients with triple-negative type and luminal-HER2(-) type disease.

Expression of prothymosin-alpha and c-myc mRNA in human gastric cancer

Prothymosin-alpha (PT-alpha) is a nuclear protein involved in cell proliferation. c-myc is implicated in the carcinogenesis of many human cancers. PT-alpha gene transcription is reported to be regulated by the c-myc gene in vitro. However, little has been reported on the PT-alpha and c-myc mRNA expressions in gastric cancer. We semi-quantitatively determined the PT-alpha and c-myc mRNA expressions in 60 pairs of gastric cancer tissue (T) and corresponding normal tissue (N) using the reverse transcriptase-polymerase chain reaction method. The average of T/N ratio was 1.20 for PT-alpha and 1.30 for c-myc. Cases demonstrating a T/N ratio of more than 1.0 were seen in 33 (55%) and 30 (50%) cases for PT-alpha and c-myc, respectively. No significant correlation was observed between either of these two mRNA expressions and any of the examined clinicopathologic factors for gastric cancer. However, a significant correlation was seen between the expressions of both genes (p<0.0001). The findings support the hypothesis that, regarding human gastric cancer, the transcription of PT-alpha is considered to be under the control of c-myc gene, however, the value of these gene expressions do not reflect biological behavior.

Microsatellite instability in Japanese colorectal carcinoma

Recent studies have shown that microsatellite instability (MSI) play an important role in the development of various types of cancer. To clarify the clinicopathologic significance of MSI in colorectal carcinoma (CRC), the presence of MSI was examined in 54 Japanese cases of CRC using the polymerase chain reaction-based method. The incidence of MSI in CRC cases was 13 out of 54 cases (24%). CRC with MSI also showed a significant tendency not to have lymph node metastasis (P<0.05), although neither the survival nor the prognosis of the cases examined in this study were available due to the short period of follow-up. The present study showed that the incidence of MSI in Japanese CRC was 24% and suggests that CRC with MSI may behave in a less malignant manner.

Clinical significance of miR-144-ZFX axis in disseminated tumour cells in bone marrow in gastric cancer cases

BACKGROUND

We previously reported that bone marrow (BM) was a homing site for gastric cancer (GC) cells leading to haematogenous metastases. There has been little study that microRNAs regulated pathways in malignant cells or host cells in BM, and thereby regulated the progression of GC.

METHODS

Both microRNA microarray and gene expression microarray analyses of total RNA from BM were conducted, comparing five early and five advanced GC patients. We focused on miR-144-ZFX axis as a candidate BM regulator of GC progression and validated the origin of the microRNA expression in diverse cell fractions (EpCAM(+)CD45(-), EpCAM(-)CD45(+), and CD14(+)) by magnetic-activated cell sorting (MACS).

RESULTS

Quantitative reverse-transcriptase (RT)-PCR analysis validated diminished miR-144 expression in stage IV GC patients with respect to stage I GC patients (t-test, P=0.02), with an inverse correlation to ZFX (ANOVA, P<0.01). Luciferase reporter assays in five GC cell lines indicated their direct binding and validated by western blotting. Pre-miR144 treatment and the resultant repression of ZFX in GC cell lines moderately upregulated their susceptibility to 5-fluorouracil chemotherapy. In MACS-purified BM fractions, the level of miR-144 expression was significantly diminished in disseminated tumour cell fraction (P=0.0005). Diminished miR-144 expression in 93 cases of primary GC indicated poor prognosis.

CONCLUSION

We speculate that disseminated cancer cells could survive in BM when low expression of miR-144 permits upregulation of ZFX. The regulation of the miR-144-ZFX axis in cancer cells has a key role in the indicator of the progression of GC cases.