Tumor Abnormality-Oriented Nanomedicine Design.

Anticancer nanomedicines have been proven effective in mitigating the side effects of chemotherapeutic drugs. However, challenges remain in augmenting their therapeutic efficacy. Nanomedicines responsive to the pathological abnormalities in the tumor microenvironment (TME) are expected to overcome the biological limitations of conventional nanomedicines, enhance the therapeutic efficacies, and further reduce the side effects. This Review aims to quantitate the various pathological abnormalities in the TME, which may serve as unique endogenous stimuli for the design of stimuli-responsive nanomedicines, and to provide a broad and objective perspective on the current understanding of stimuli-responsive nanomedicines for cancer treatment. We dissect the typical transport process and barriers of cancer drug delivery, highlight the key design principles of stimuli-responsive nanomedicines designed to tackle the series of barriers in the typical drug delivery process, and discuss the "all-into-one" and "one-for-all" strategies for integrating the needed properties for nanomedicines. Ultimately, we provide insight into the challenges and future perspectives toward the clinical translation of stimuli-responsive nanomedicines.

Identification of cortical arteries and veins in awake mice using two-photon microscopy.

Distinguishing arteries from veins in the cerebral cortex is critical for studying hemodynamics under pathophysiological conditions, which plays an important role in the diagnosis and treatment of various vessel-related diseases. However, due to the complexity of the cerebral vascular network, it is challenging to identify arteries and veins in vivo. Here, we demonstrate an artery-vein separation method that employs a combination of multiple scanning modes of two-photon microscopy and a custom-designed stereoscopic fixation device for mice. In this process, we propose a novel method for determining the line scanning direction, which allows us to determine the blood flow directions. The vasculature branches have been identified using an optimized z-stack scanning mode, followed by the separation of blood vessel types according to the directions of blood flow and branching patterns. Using this strategy, the penetrating arterioles and penetrating venules in awake mice could be accurately identified and the type of cerebral thrombus has been also successfully isolated without any empirical knowledge or algorithms. Our research presents a new, more accurate, and efficient method for cortical artery-vein separation in awake mice, providing a useful strategy for the application of two-photon microscopy in the study of cerebrovascular pathophysiology.

Ginsenoside Rg3 overcomes tamoxifen resistance through inhibiting glycolysis in breast cancer cells.

Tamoxifen (TAM) resistance poses a significant clinical challenge in human breast cancer and exhibits high heterogeneity among different patients. Rg3, an original ginsenoside known to inhibit tumor growth, has shown potential for enhancing TAM sensitivity in breast cancer cells. However, the specific role and underlying mechanisms of Rg3 in this context remain unclear. Aerobic glycolysis, a metabolic process, has been implicated in chemotherapeutic resistance. In this study, we demonstrate that elevated glycolysis plays a central role in TAM resistance and can be effectively targeted and overcome by Rg3. Mechanistically, we observed upregulation of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a key mediator of glycolysis, in TAM-resistant MCF-7/TamR and T-47D/TamR cells. Crucially, PFKFB3 is indispensable for the synergistic effect of TAM and Rg3 combination therapy, which suppresses cell proliferation and glycolysis in MCF-7/TamR and T-47D/TamR cells, both in vitro and in vivo. Moreover, overexpression of PFKFB3 in MCF-7 cells mimicked the TAM resistance phenotype. Importantly, combination treatment significantly reduced TAM-resistant MCF-7 cell proliferation in an in vivo model. In conclusion, this study highlights the contribution of Rg3 in enhancing the therapeutic efficacy of TAM in breast cancer, and suggests that targeting TAM-resistant PFKFB3 overexpression may represent a promising strategy to improve the response to combination therapy in breast cancer.

Alkylated EDTA potentiates antibacterial photodynamic activity of protoporphyrin.

Antibiotic resistance has garnered significant attention due to the scarcity of new antibiotics in development. Protoporphyrin IX (PpIX)-mediated photodynamic therapy shows promise as a novel antibacterial strategy, serving as an alternative to antibiotics. However, the poor solubility of PpIX and its tendency to aggregate greatly hinder its photodynamic efficacy. In this study, we demonstrate that alkylated EDTA derivatives (aEDTA), particularly C14-EDTA, can enhance the solubility of PpIX by facilitating its dispersion in aqueous solutions. The combination of C14-EDTA and PpIX exhibits potent antibacterial activity against Staphylococcus aureus (S. aureus) when exposed to LED light irradiation. Furthermore, this combination effectively eradicates S. aureus biofilms, which are known to be strongly resistant to antibiotics, and demonstrates high therapeutic efficacy in an animal model of infected ulcers. Mechanistic studies reveal that C14-EDTA can disrupt PpIX crystallization, increase bacterial membrane permeability and sequester divalent cations, thereby improving the accumulation of PpIX in bacteria. This, in turn, enhances reactive oxygen species (ROS) production and the antibacterial photodynamic activity. Overall, this effective strategy holds great promise in combating antibiotic-resistant strains.

Role of Micelle Size in Cell Transcytosis-Based Tumor Extravasation, Infiltration, and Treatment Efficacy.

Transcytosis-based active transport of cancer nanomedicine has shown great promise for enhancing its tumor extravasation and infiltration and antitumor activity, but how the key nanoproperties of nanomedicine, particularly particle size, influence the transcytosis remains unknown. Herein, we used a transcytosis-inducing polymer, poly[2-(N-oxide-N,N-diethylamino)ethyl methacrylate] (OPDEA), and fabricated stable OPDEA-based micelles with different sizes (30, 70, and 140 nm in diameter) from its amphiphilic block copolymer, OPDEA-block-polystyrene (OPDEA-PS). The study of the micelle size effects on cell transcytosis, tumor extravasation, and infiltration showed that the smallest micelles (30 nm) had the fastest transcytosis and, thus, the most efficient tumor extravasation and infiltration. So, the 7-ethyl-10-hydroxyl camptothecin (SN38)-conjugated OPDEA micelles of 30 nm had much enhanced antitumor activity compared with the 140 nm micelles. These results are instructive for the design of active cancer nanomedicine.

Highly Sensitive Imaging of Tumor Metastasis Based on the Targeting and Polarization of M2-like Macrophages.

Tumor-associated macrophages, especially M2-like macrophages, are extensively involved in tumor growth and metastasis, suppressing the innate immunity to help tumor cells escape and reshaping the microenvironment to help metastatic cells grow. However, in vivo, real-time visualized migration of M2-like macrophages has never been explored to monitor the tumor metastasis process. Herein, we prepared an M2-like macrophage-targeting nitric oxide (NO)-responsive nanoprobe (NRP@M-PHCQ) consisting of an amphiphilic block copolymer with mannose and hydroxychloroquine (HCQ) moieties (denoted as M-PHCQ) and a NO-responsive NIR-II probe (denoted as NRP). The mannose moieties provided M2-like macrophage-targeting capacity, and the HCQ moieties polarized M2-like macrophages to M1-like ones with enhanced NO secretion. Consequently, NRP@M-PHCQ was lit up by the secreted NO to visualize the migration and polarization of M2-like macrophages in real time. In vivo metastasis imaging with NRP@M-PHCQ successfully tracked early tumor metastasis in the lymph nodes and the lungs with high sensitivity, even superior to Luci-labeled bioluminescence imaging, suggesting the extensive distribution and critical role of M2-like macrophages in tumor metastasis. In general, this work provided a new strategy to sensitively image metastatic tumors by tracking the polarization of M2-like macrophages and visually disclosed the critical role of M2-like macrophages in early tumor metastasis.

Active Breathing Coordinator reduces radiation dose to the stomach in patients with left breast cancer.

BACKGROUND/PURPOSE: Gastric dose parameters comparison for deep inspiration breath-hold (DIBH) or free breathing (FB) mode during radiotherapy (RT) for left-sided breast cancer patients (LSBCPs) has not been investigated before. This study aimed to analyze the impact of Active Breath Coordinator (ABC)-DIBH technique on the dose received by the stomach during RT for LSBCPs and to provide organ-specific dosimetric parameters. MATERIALS AND METHODS: The study included 73 LSBCPs. The dosimetric parameters of the stomach were compared between FB and DIBH mode. The correlation between the stomach volume and dosimetric parameters was analyzed. RESULTS: Compared to FB mode, statistically significant reductions were observed in gastric dose parameters in ABC-DIBH mode, including Dmax (46.60 vs 17.25, p < 0.001), D1cc (38.42 vs 9.60, p < 0.001), Dmean (4.10 vs 0.80, p < 0.001), V40Gy (0.50 vs 0.00, p < 0.001), V30Gy (6.30 vs 0.00, p < 0.001), V20Gy (20.80 vs 0.00, p < 0.001), V10Gy (51.10 vs 0.77, p < 0.001), and V5Gy (93.20 vs 9.60, p < 0.001). ABC-DIBH increased the distance between the stomach and the breast PTV when compared to FB, from 1.3 cm to 2.8 cm (p < 0.001). Physiologic decrease in stomach volume was not found from FB to ABC-DIBH (415.54 cm3 vs 411.61 cm3, p = 0.260). The stomach volume showed a positive correlation with V40Gy (r2 = 0.289; p < 0.05), V30Gy (r2 = 0.287; p < 0.05), V20Gy (r2 = 0.343; p < 0.05), V10Gy (r2 = 0.039; p < 0.001), V5Gy (r2 = 0.439; p < 0.001), Dmax (r2 = 0.269; p < 0.05) and D1cc (r2 = 0.278; p < 0.05) in FB mode. While in ABC-DIBH mode, most stomach dosimetric parameters were not correlated with gastric volume. CONCLUSIONS: The implementation of ABC-DIBH in LSBCPs radiotherapy resulted in lower irradiation of the stomach. Larger stomach volume was associated with statistically significantly higher dose irradiation in FB mode. To reduce radiotherapy related side effects in FB mode, patients should be fast for at least 2 hours before the CT simulation and treatment.

Natural Polyphenols-Platinum Nanocomplexes Stimulate Immune System for Combination Cancer Therapy.

Nanocarriers have been employed extensively to enhance drug delivery efficacy and reduce the side effect. However, carrier materials for drug delivery have challenging aspects, including safety concerns, low drug content, complexity in preparation, and low reproducibility. Herein, we propose a facile, universal, and green preparation way to use natural polyphenols to build platinum nanocomplex with stable structure, proper size, and high Pt content. The nanocomplexes are constructed by metal-polyphenol coordination using natural polyphenols and 1,2-diaminocyclohexane-Pt (II), enabling dual-responsive drug release behavior. For proof of concept, we demonstrate the antitumor activity of the Pt nanocomplex using a representative tannic acid-Pt nanocomplex (denoted as PTI). PTI can induce intensive tumor cell apoptosis, trigger immunogenic cell death (ICD), remarkably promote cytotoxic T lymphocytes (CTLs) infiltration in tumors, and significantly reduce immunosuppression of the tumor microenvironments, thus stimulating potent antitumor immune responses and showing effective antitumor activity by synergizing immune checkpoint blockade (ICB) therapy.

Aminopeptidase N-Responsive Conjugates with Tunable Charge-Reversal Properties for Highly Efficient Tumor Accumulation and Penetration.

Tumor enzyme-responsive charge-reversal carriers can induce efficient transcytosis and lead to efficient tumor infiltration and potent anticancer efficacy. However, the correlations of molecular structure with charge-reversal property, tumor penetration, and drug delivery efficiency are unknown. Herein, aminopeptidase N (APN)-responsive conjugates were synthesized to investigate these correlations. We found that the monomeric unit structure and the polymer chain structure determined the enzymatic hydrolysis and charge-reversal rates, and accordingly, the transcytosis and tumor accumulation and penetration of the APN-responsive conjugates. The conjugate with moderate APN responsiveness balanced the in vitro transcytosis and in vivo overall drug delivery process and achieved the best tumor delivery efficiency, giving potent antitumor efficacy. This work provides new insight into the design of tumor enzyme-responsive charge-reversal nanomedicines for efficient cancer drug delivery.

Molecularly Precise, Bright, Photostable, and Biocompatible Cyanine Nanodots as Alternatives to Quantum Dots for Biomedical Applications.

Fluorescent imaging with fluorophores has become a powerful way to explore complex biological systems and visualize nanoparticles for drug delivery. However, it is challenging to develop fluorophores with ideal physical and optical properties. We report a method to synthesize cyanine nanodots with a single-molecule structure, well-defined particle size, customizable fluorescent spectrum, and bright and stable fluorescence. These cyanine nanodots are acquired by the divergent synthesis of cyanine-dye-cored polylysine (PLL) dendrimers. We demonstrated the feasibility of the method by synthesizing cyanine 3 (Cy3), cyanine 5 (Cy5), or cyanine 7 (Cy7) cored single-molecule nanodots up to eight generations with a size of around 11 nm. We show that these cyanine nanodots are capable of multiple biomedical applications, including multicolor cellular tracing and cancer imaging. These cyanine nanodots possess many merits of organic dots and quantum dots that are promising for future application.

Drug-binding albumins forming stabilized nanoparticles for efficient anticancer therapy.

Albumin is a serum transport protein, which has been utilized as a carrier for a variety of drugs to improve their delivery efficiency and to obtain favorable pharmacokinetic profiles. However, natural albumin possesses only a few high-affinity binding sites for a limited number of drugs. This results in deficiencies in drug-loading and serum stability, and consequently, in impaired therapeutic efficacy. Herein, BSA was modified with different isothiocyanate conjugates (BSA-ITCs), which self-assembled with paclitaxel (PTX) to produce BSA-ITCs/PTX nanoparticles. Among these BSA-ITCs, phenethyl isothiocyanate (PEITC)-modified BSA (BSA-PEITC35) conjugates effectively loaded PTX and formed highly stable BSA-PEITC35/PTX nanoparticles. Molecular modeling studies suggested that PEITC groups in BSA-PEITC35 can significantly lower the PTX binding free energy. BSA-PEITC35/PTX showed enhanced stability, prolonged blood circulation and increased tumor accumulation than unmodified BSA/PTX, and exerted more potent antitumor activity than both BSA/PTX and Abraxane in subcutaneous mouse tumor models after intravenous administration.

Glycyrrhizin Acid and Glycyrrhetinic Acid Modified Polyethyleneimine for Targeted DNA Delivery to Hepatocellular Carcinoma.

In the last 2-3 decades, gene therapy represented a promising option for hepatocellular carcinoma (HCC) treatment. However, the design of safe and efficient gene delivery systems is still one of the major challenges that require solutions. In this study, we demonstrate a versatile method for covalent conjugation of glycyrrhizin acid (GL) or glycyrrhetinic acid (GA) to increase the transfection efficiency of Polyethyleneimine (PEI, Mw 1.8K) and improve their targeting abilities of hepatoma carcinoma cells. GA and GL targeting ligands were grafted to PEI via N-acylation, and we systematically investigated their biophysical properties, cytotoxicity, liver targeting and transfection efficiency, and endocytosis pathway trafficking. PEI-GA0.75, PEI-GL10.62 and PEI-GL20.65 conjugates caused significant increases in gene transfection efficiency and superior selectivity for HepG2 cells, with all three conjugates showing specific recognition of HepG2 cells by the free GA competition assay. The endocytosis inhibition and intracellular trafficking results indicated that PEI-GA0.75 and GL10.62 conjugates behaved similarly to SV40 virus, by proceeding via the caveolae- and clathrin-independent mediated endocytosis pathway and bypassing entry into lysosomes, with an energy independent manner, achieving their high transfection efficiencies. In the HepG2 intraperitoneal tumor model, PEI-GA0.75 and PEI-GL10.62 carrying the luciferase reporter gene gained high gene expression, suggesting potential use for in vivo application.

Clinical features and dysfunctions of iron metabolism in Parkinson disease patients with hyper echogenicity in substantia nigra: a cross-sectional study.

BACKGROUND: Transcranial ultrasound is a useful tool for providing the evidences for the early diagnosis and differential diagnosis of Parkinson disease (PD). However, the relationship between hyper echogenicity in substantia nigra (SN) and clinical symptoms of PD patients remains unknown, and the role of dysfunction of iron metabolism on the pathogenesis of SN hyper echogenicity is unclear. METHODS: PD patients was detected by transcranial sonography and divided into with no hyper echogenicity (PDSN-) group and with hyper echogenicity (PDSN+) group. Motor symptoms (MS) and non-motor symptoms (NMS) were evaluated, and the levels of iron and related proteins in serum and cerebrospinal fluid (CSF) were detected for PD patients. Data comparison between the two groups and correlation analyses were performed. RESULTS: PDSN+ group was significantly older, and had significantly older age of onset, more advanced Hohen-Yahr stage, higher SCOPA-AUT score and lower MoCA score than PDSN- group (P < 0.05). Compared with PDSN- group, the levels of transferrin and light-ferritin in serum and iron level in CSF were significantly elevated (P < 0.05), but ferroportin level in CSF was significantly decreased in PDSN+ group (P < 0.05). CONCLUSIONS: PD patients with hyper echogenicity in SN are older, at more advanced disease stage, have severer motor symptoms, and non-motor symptoms of cognitive impairment and autonomic dysfunction. Hyper echogenicity of SN in PD patients is related to dysfunction of iron metabolism, involving increased iron transport from peripheral system to central nervous system, reduction of intracellular iron release and excessive iron deposition in brain.

Correlates of Immune Response in Trichinella spiralis Infection.

Trichinella spiralis infection induces Trichinella-specific IgG antibody and high level of blood eosinophil. However, the kinetics induced by different parasite burdens during infectious periods remains unclear. In this study, rats were infected with 100, 1000, or 3000 larvae of T. spiralis (100 TS, 1000 TS, or 3000 TS). Correlates of eosinophils, antibody responses, and Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES) with worm burdens were evaluated at 1 week, 2 weeks, 1 month, and 2 months postinfection. Heavy infections (1000 TS and 3000 TS) showed significantly higher levels of eosinophil, IgG, and IgG1 antibody responses at 2 weeks postinfection compared to light infection (100 TS). The highest RANTES mRNA expression was also found in the heavy infection group (3000 TS). The results indicate, at early stage of infection (week 2), heavy infection induced higher levels of IgG, IgG1, eosinophil, and RANTES responses. However, at late stage of infection (month 2), there were no correlates of immunity with parasite burdens. Higher levels of IgG and IgG1 antibody responses are critical in heavy T. spiralis infection. These results provide important information in evaluating immune responses by T. spiralis infective stage during the T. spiralis infection.

The aflatoxin-detoxifizyme specific expression in the parotid gland of transgenic pigs.

Producing aflatoxin-detoxifizyme (ADTZ) in pigs to control the AFT contamination of pig feed is a new research strategy by transgenic technology. In this study, transgenic pigs specifically expressing ADTZ gene in the parotid gland were successfully produced by somatic cell nuclear transfer technology. The ADTZ activity in saliva of 6 transgenic pigs was found to be 7.11 ± 2.63 U/mL. The feeding trial with aflatoxin (AFT) results showed that there were significant difference about the serum biochemical index such as total protein (TP), albumin (ALB), globulin (GLB) contents and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity and AFT residues in serum and liver between the pigs in the test treatment (transgenic pigs) producing ADTZ and those in the positive control (P < 0.05). In order to investigate the inheritance of the transgene, 11 G1 transgenic pigs were successfully obtained. The ADTZ activity in saliva of 11 G1 transgenic pigs was found to be 5.82 ± 1.53 U/mL. The feeding trial with AFT results showed that the serum biochemical index containing TP, ALB and GLB contents and ALT and AST activity and AFB1 residues in serum and liver of the pigs in the test treatment (transgenic pigs) producing ADTZ were significantly different than those in the positive control (P < 0.05). The above results demonstrated that ADTZ produced in transgenic pigs could improve the effect of the AFT contamination of feed on pigs.

Influenza M1 Virus-Like Particles Consisting of Toxoplasma gondii Rhoptry Protein 4.

Toxoplasma gondii infections occur throughout the world, and efforts are needed to develop various vaccine candidates expressing recombinant protein antigens. In this study, influenza matrix protein (M1) virus-like particles (VLPs) consisting of T. gondii rhoptry antigen 4 (ROP4 protein) were generated using baculovirus (rBV) expression system. Recombinant ROP4 protein with influenza M1 were cloned and expressed in rBV. SF9 insect cells were coinfected with recombinant rBVs expressing T. gondii ROP4 and influenza M1. As the results, influenza M1 VLPs showed spherical shapes, and T. gondii ROP4 protein exhibited as spikes on VLP surface under transmission electron microscopy (TEM). The M1 VLPs resemble virions in morphology and size. We found that M1 VLPs reacted with antibody from T. gondii-infected mice by western blot and ELISA. This study demonstrated that T. gondii ROP4 protein can be expressed on the surface of influenza M1 VLPs and the M1 VLPs containing T. gondii ROP4 reacted with T. gondii-infected sera, indicating the possibility that M1 VLPs could be used as a coating antigen for diagnostic and/or vaccine candidate against T. gondii infection.

Excessive Iron and α-Synuclein Oligomer in Brain are Relevant to Pure Apathy in Parkinson Disease.

OBJECTIVES: To investigate the demographic features, clinical features, and potential mechanism in patients with Parkinson disease (PD) with pure apathy. METHOD: A total of 145 patients with PD without depression and dementia and 30 age-matched controls were consecutively recruited. Patients with PD were evaluated by Apathy Scale (AS), scales for motor symptoms and quality of life. The levels of iron, oxidative and neuroinflammatory factors, α-synuclein oligomer, and dopamine in cerebrospinal fluid (CSF) from patients with PD and controls were detected by enzyme-linked immunosorbent assay, chemical colorimetric method, and high-performance liquid chromatography. Comparisons between PD with pure apathy and with no pure apathy groups and correlation between AS score and the levels of above factors were analyzed. RESULTS: There were 64 (44.14%) cases in PD-apathy group. The PD-apathy group had older age, (97.81 ± 10.82) years versus (61.86 ± 10.80) years, and severer quality of life (P < .05). The PD-apathy and PD without apathy groups presented no remarkable differences in motor symptoms (P > .05). The levels of iron, hydroxyl radical (·OH), hydrogen peroxide (H2O2), and α-synuclein oligomer in CSF in PD-apathy group were significantly higher than that in PD without the apathy group (P < .05). In patients with PD, the AS score was positively correlated with the levels of iron, ·OH, H2O2 and α-synuclein oligomer in CSF (r = 19.838, .063, 1.046, and 0.498, respectively, P < .05). In PD-apathy group, iron level was positively correlated with ·OH level (r = .011, P < .05), and H2O2 level was positively correlated with α-synuclein oligomer level in CSF (r = .045, P < .05). CONCLUSION: Patients with PD had high prevalence of pure apathy. Patients with PD having pure apathy had older age. Pure apathy reduced quality of life for patients without worsening motor function. Excessive iron and α-synuclein oligomer in brain commonly contributed to pure apathy of PD through potential mechanism of oxidative stress.

Methylone-induced hyperthermia and lethal toxicity: role of the dopamine and serotonin transporters.

Methylone (2-methylamino-1-[3,4-methylenedioxy-phenyl]propan-1-one), an amphetamine analog, has emerged as a popular drug of abuse worldwide. Methylone induces hyperthermia, which is thought to contribute toward the lethal consequences of methylone overdose. Methylone has been assumed to induce hyperthermic effects through inhibition of serotonin and/or dopamine transporters (SERT and DAT, respectively). To examine the roles of each of these proteins in methylone-induced toxic effects, we used SERT and DAT knockout (KO) mice and assessed the hyperthermic and lethal effects caused by a single administration of methylone. Methylone produced higher rates of lethal toxicity compared with other amphetamine analogs in wild-type mice. Compared with wild-type mice, lethality was significantly lower in DAT KO mice, but not in SERT KO mice. By contrast, only a slight diminution in the hyperthermic effects of methylone was observed in DAT KO mice, whereas a slight enhancement of these effects was observed in SERT KO mice. Administration of the selective D1 receptor antagonist SCH 23390 and the D2 receptor antagonist raclopride reduced methylone-induced hyperthermia, but these drugs also had hypothermic effects in saline-treated mice, albeit to a smaller extent than the effects observed in methylone-treated mice. In contradistinction to 3,4-methylenedioxymethamphetamine, which induces its toxicity through SERT and DAT, these data indicate that DAT, but not SERT, is strongly associated with the lethal toxicity produced by methylone, which did not seem to be dependent on the hyperthermic effects of methylone. DAT is therefore a strong candidate molecule for interventions aimed at preventing acute neurotoxic and lethal effects of methylone.

[Expression and clinical significance of MTDH and VEGF in triple-negative breast cancer].

OBJECTIVE: To study the expression and clinical significance of MTDH and VEGF in triple-negative breast cancer (TNBC). METHODS: Tissue samples of 168 breast cancers (including 112 TNBC tissue and 56 non-TNBC tissue), 10 breast fibroadenomas and 15 normal breast tissues were collected. Postoperative specimens were examined by immunohistochemistry for MTDH and VEGF expression. The correlation between the expression of MTDH and VEGF and clinicopathological features was analyzed. RESULTS: MTDH and VEGF were expressed in 57.1% and 49.4% of breast cancer patients, 64.3% and 56.3% in TNBC patients, respectively, significantly higher than that in the non-TNBC tissues, breast fibroadenomas and normal breast tissues (P<0.05 for all). Statistically significant correlation was found between the MTDH and VEGF expressions (r=0.356, P<0.001). Moreover, MTDH expression was correlated with tumor size, BMI index, lymph node metastasis, pathological stage, recurrence and metastasis, and the expression of p53 and Ki-67 proteins (P<0.05 for all). The VEGF protein expression was correlated with lymph node metastasis, pathological staging, recurrence and metastasis, and the expression of Ki-67 protein (P<0.05 for all). The patients with high expression of MTDH and VEGF showed a lower DFS and OS (P<0.05 for both). CONCLUSIONS: MTDH and VEGF expression may be correlated with tumor angiogenesis and progression and has the potential to be valuable prognostic factors in patients with TNBC.

MTDH mediates trastuzumab resistance in HER2 positive breast cancer by decreasing PTEN expression through an NFκB-dependent pathway.

BACKGROUND: Trastuzumab resistance is almost inevitable in the management of human epidermal growth factor receptor (HER) 2 positive breast cancer, in which phosphatase and tensin homolog deleted from chromosome 10 (PTEN) loss is implicated. Since metadherin (MTDH) promotes malignant phenotype of breast cancer, we sought to define whether MTDH promotes trastuzumab resistance by decreasing PTEN expression through an NFκB-dependent pathway. METHODS: The correlations between MTDH and PTEN expressions were analyzed both in HER2 positive breast cancer tissues and trastuzumab resistant SK-BR-3 (SK-BR-3/R) cells. Gene manipulations of MTDH and PTEN levels by knockdown or overexpression were utilized to elucidate molecular mechanisms of MTDH and PTEN implication in trastuzumab resistance. For in vivo studies, SK-BR-3 and SK-BR-3/R cells and modified derivatives were inoculated into nude mice alone or under trastuzumab exposure. Tumor volumes, histological examinations as well as Ki67 and PTEN expressions were revealed. RESULTS: Elevated MTDH expression indicated poor clinical benefit, shortened progression free survival time, and was negatively correlated with PTEN level both in HER2 positive breast cancer patients and SK-BR-3/R cells. MTDH knockdown restored PTEN expression and trastuzumab sensitivity in SK-BR-3/R cells, while MTDH overexpression prevented SK-BR-3 cell death under trastuzumab exposure, probably through IκBα inhibition and nuclear translocation of p65 which subsequently decreased PTEN expression. Synergized effect of PTEN regulation were observed upon MTDH and p65 co-transfection. Forced PTEN expression in SK-BR-3/R cells restored trastuzumab sensitivity. Furthermore, decreased tumor volume and Ki67 level as well as increased PTEN expression were observed after MTDH knockdown in subcutaneous breast cancer xenografts from SK-BR-3/R cells, while the opposite effect were found in grafts from MTDH overexpressing SK-BR-3 cells. CONCLUSIONS: MTDH overexpression confers trastuzumab resistance in HER2 positive breast cancer. MTDH mediates trastuzumab resistance, at least in part, by PTEN inhibition through an NFκB-dependent pathway, which may be utilized as a promising therapeutic target for HER2 positive breast cancer.