Triple negative breast cancer (TNBC) is very aggressive and currently has no specific therapeutic targets, such as hormone receptors or human epidermal growth factor receptor type 2 (HER2); therefore, prognosis is poor. Bortezomib, a proteasome inhibitor, may exert efficacy in TNBC through its multiple cellular effects. Here, we tested the efficacy of bortezomib and examined the drug mechanism in breast cancer cells.Five breast cancer cell lines: TNBC HCC-1937, MDA-MB-231, and MDA-MB-468; HER2-overexpressing MDA-MB-453; and estrogen receptor positive MCF-7 were used for in vitro studies. Apoptosis was examined by both flow cytometry and Western Blot. Signal transduction pathways in cells were assessed by Western Blot. Gene silencing was done by small interfering RNA (siRNA). In vivo efficacy of bortezomib was tested in nude mice with breast cancer xenografts. Immunohistochemical study was performed on tumor tissues from patients with TNBC.Bortezomib induced significant apoptosis, which was independent of its proteasome inhibition, in the three TNBC cell lines, but not in MDA-MB-453 or MCF-7 cells. Furthermore, cancerous inhibitor of protein phosphatase 2A (CIP2A), a cellular inhibitor of protein phosphatase 2A (PP2A), mediated the apoptotic effect of bortezomib. We showed that bortezomib inhibited CIP2A in association with p-Akt downregulation in a dose- and time-dependent manner in all sensitive TNBC cells, whereas no alterations in CIP2A expression and p-Akt were noted in bortezomib-resistant cells. Overexpression of CIP2A upregulated p-Akt and protected MDA-MB-231 and MDA-MB-468 cells from bortezomib-induced apoptosis, whereas silencing CIP2A by siRNA overcame the resistance to bortezomib-induced apoptosis in MCF-7 cells. In addition, bortezomib downregulated CIP2A mRNA but did not affect the degradation of CIP2A protein. Furthermore, bortezomib exerted in vivo antitumor activity in HCC-1937 xenografted tumors, but not in MCF-7 tumors. Bortezomib downregulated CIP2A expression in the HCC-1937 tumors but not in the MCF-7 tumors. Importantly, CIP2A expression is readily detectable in tumor samples from TNBC patients.CIP2A is a major determinant mediating bortezomib-induced apoptosis in TNBC cells. CIP2A may thus be a potential therapeutic target in TNBC.
Abstract Background: Interfering the oncogenic STAT3 signaling is considered as promising anti-cancer strategy. Previously, we have reported an obatoclax analogue, SC-2001, as a novel STAT3 inhibitor in hepatocellular carcinoma cells (Cancer Letter 2012). Here, we examined the efficacy and drug mechanism of SC-2001 in breast cancer cells. Methods: Human breast cancer cell lines were used for in vitro studies. Cell viability was examined by MTT assay. Apoptosis was examined by both flow cytometry and western blot. Signal transduction pathways in cells were assessed by western blot. Small interference RNA was used to knockdown SHP-1. Quantitative RT-PCR was used for assessing gene transcription. In vivo efficacy of SC-2001 was tested in xenografted nude mice. Results: SC-2001 inhibited cell growth and induced apoptosis in breast cancer cell lines (MDA-MB-468, MDA-MB-231, MDA-MB-453, MCF-7 and HCC 1937). SC-2001 downregulated the phosphorylation of STAT3 (Tyr 705) and subsequently inhibited its transcriptional activities in a dose-dependent manner. STAT3-regulated proteins, including Mcl-1, survivin and cyclin D1, were also repressed by SC-2001. Over-expression of STAT3 in MDA-MB-468 cells protected cells from SC-2001-induced apoptosis. Moreover, SC-2001 enhanced the expression of SHP-1, a negative regulator of STAT3, in a time-dependent manner. The enhanced SHP-1 expression, in conjunction with increased SHP-1 phosphatase activity, was mediated by upregulated transcription. Furthermore, co-immunoprecipitation experiment showed that SC-2001 upregulated SHP-1 expression through enhanced transcription by RFX-1 transcription factor. Importantly, SC-2001 showed efficacious antitumor activity and p-STAT3 downregulation in MDA-MB-468 xenograft tumors. Conclusion: Our results suggest that SC-2001 induced apoptosis in breast cancer cells, and that this effect is mediated through RFX-1 upregulated SHP-1 expression and SHP-1-dependent STAT3 inactivation. (Supported by Yen Tjing Ling Medical Foundation; NSC 101-2325-B-075-006, NSC-102-2325-B-075-006 and NSC 100-2325-B-010-007; and V100-D-005-4) Citation Format: Chun-Yu Liu, Jung-Chen Su, Ling-Ming Tseng, Pei-Yi Chu, Wei-Tien Tai, Chung-Wai Shiau, Kuen-Feng Chen. Obatoclax analogue SC-2001 inhibits STAT3 phosphorylation by enhancing protein tyrosine phosphatase SHP-1 expression and induces apoptosis in human breast cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3803. doi:10.1158/1538-7445.AM2014-3803
Spindle cell squamous cell carcinoma (SpCC) is a poorly differentiated subtype of squamous cell carcinoma (SqCC). We report a case with second primary oropharyngeal SpCC after seven years of complete treatment of SqCC. The patient underwent surgery and adjuvant chemoradiotherapy. Relevant literature about SpCC was reviewed.
Roche's AVENIO ctDNA analysis kits and bioinformatics analysis (the AVENIO system) are accessible to all NGS laboratories. We have developed an approach, namely the Sec-Seq system, and compared the accuracy, sensitivity, repeatability and economic cost between the AVENIO system and the Sec-Seq system. Both methods share the comparable accuracy and sensitivity in detecting the variant allele frequency of 0.0005, while the Sec-Seq system shows better accuracy in detecting the variant allele frequency of 0.001. Furthermore, the Sec-Seq system displays a much better detection sensitivity than the AVENIO system. The Sec-Seq system has satisfactory performance in detecting the rare genetic variants in ctDNA with lower economic cost compared with the AVENIO system.
To investigate the role of peritoneal macrophage (PM) polarization in the therapeutic effect of abdominal paracentesis drainage (APD) on severe acute pancreatitis (SAP).SAP was induced by 5% Na-taurocholate retrograde injection in Sprague-Dawley rats. APD was performed by inserting a drainage tube with a vacuum ball into the lower right abdomen of the rats immediately after the induction of SAP. To verify the effect of APD on macrophages, PMs were isolated and cultured in an environment, with the peritoneal inflammatory environment simulated by the addition of peritoneal lavage in complete RPMI 1640 medium. Hematoxylin and eosin staining was performed. The levels of pancreatitis biomarkers amylase and lipase as well as the levels of inflammatory mediators in the blood and peritoneal lavage were determined. The polarization phenotypes of the PMs were identified by detecting the marker expression of M1/M2 macrophages via flow cytometry, qPCR and immunohistochemical staining. The protein expression in macrophages that had infiltrated the pancreas was determined by Western blot.APD treatment significantly reduced the histopathological scores and levels of amylase, lipase, tumor necrosis factor-α and interleukin (IL)-1β, indicating that APD ameliorates the severity of SAP. Importantly, we found that APD treatment polarized PMs towards the M2 phenotype, as evidenced by the reduced number of M1 macrophages and the reduced levels of pro-inflammatory mediators, such as IL-1β and L-selectin, as well as the increased number of M2 macrophages and increased levels of anti-inflammatory mediators, such as IL-4 and IL-10. Furthermore, in an in vitro study wherein peritoneal lavage from the APD group was added to the cultured PMs to simulate the peritoneal inflammatory environment, PMs also exhibited a dominant M2 phenotype, resulting in a significantly lower level of inflammation. Finally, APD treatment increased the proportion of M2 macrophages and upregulated the expression of the anti-inflammatory protein Arg-1 in the pancreas of SAP model rats.These findings suggest that APD treatment exerts anti-inflammatory effects by regulating the M2 polarization of PMs, providing novel insights into the mechanism underlying its therapeutic effect.
Background: Radiation dosimetry plays the crucial role for estimating the process of diagnosis as well as for the comparison of various diagnostic methods. PET/SPECT scanning is time-consuming if sufficient data are needed to derive the biodistribution. In this study, we propose using TLDs (thermoluminescent dosimeters) measurements to estimate the dosimetry of each interested organ for 18F-FDG administration. MIRD method used in this study will serve as a golden standard. Methods: All studies were done with a whole-body PET Scanner (EXACT PET scanner HR(superscript +), Siemens). The source organs selected to scan are brain, thyroid, heart, lungs, liver, kidneys, spleen and bladder. Accumulated activities were estimated from the activity distribution of 4 time-points (including time zero) using the trapezoidal rule and physical decay fitting. One or two TLDs (CaSO4: Tm; Li2B4O: Cu) were attached to the surface of each of the eight sources organ. PET scanning with ROI selecting, MIRD method has been used to estimate dosimetry, simultaneously TLD dosimetry was measured and modified. Results: Residence times of 18F-FDG for each organ of the subjects have been calculated. Dose estimated both from PET scanning with MIRD method as well as modified TLD measured dose were performed. Dose calculated by MIRD was always larger than that of TLD. The ratios (MIRD/TLD) for brain and bladder were significantly larger than those for other organs. Conclusions: The anatomy and the pathological condition of a patient affected the dose assessment from TLD measurement. Dose calculated by MIRD was always larger than that of TLD, because the dose measured by TLD was attenuated by the tissues/organs which were between the real organ and TLD. Both MIRD and TLD methods can be used to assess the internal dosimetry of 18F-FDG. However, if we want to roughly derive the accumulated activity as well as the dose of each specified organ, TLDs method should be a more convenient approach if the MIRD/TLD ratios derived in this study are used.
This work presents the use of a short time Fourier transform to determine the natural frequencies, damping ratios, and mode shapes of a structure from its free vibration or earthquake response data. The short time Fourier transform is applied to the measured acceleration responses of a structural system, and to reconstruct the autoregressive with exogenous input (ARX) model in time-frequency domain. The accuracy of this procedure is numerically confirmed; the effects of the length of frequency band and noise on the ability to accurately estimate the dynamic characteristics are also investigated. The feasibility of the present procedure to elucidate real structures is demonstrated through processing the measured responses of steel frames in shaking table tests.
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