The role of TRPV4 in programmed cell deaths.

Programmed cell death is a major life activity of both normal development and disease. Necroptosis is early recognized as a caspase-independent form of programmed cell death followed obviously inflammation. Apoptosis is a gradually recognized mode of cell death that is characterized by a special morphological changes and unique caspase-dependent biological process. Ferroptosis, pyroptosis and autophagy are recently identified non-apoptotic regulated cell death that each has its own characteristics. The transient receptor potential vanilloid 4 (TRPV4) is a kind of nonselective calcium-permeable cation channel, which is received more and more attention in biology studies. It is widely expressed in human tissues and mainly located on the membrane of cells. Several researchers have identified that the influx Ca2+ from TRPV4 acts as a key role in the loss of cells by apoptosis, ferroptosis, necroptosis, pyroptosis and autophagy via mediating endoplasmic reticulum (ER) stress, oxidative stress and inflammation. This effect is bad for the normal function of organs on the one hand, on the other hand, it is benefit for anticancer activities. In this review, we will summarize the current discovery on the role and impact of TRPV4 in these programmed cell death pathological mechanisms to provide a new prospect of gene therapeutic target of related diseases.

Targeted Nanodrugs to Destroy the Tumor Extracellular Matrix Barrier for Improving Drug Delivery and Cancer Therapeutic Efficacy.

One of the main reasons why most cancer patients do not respond well to chemotherapy is that drugs cannot accumulate in tumors at an optimal dose, eventually resulting in failure to prevent cancer cell growth. To improve drug delivery efficiency, we engineered a highly efficient tumor-targeted and stroma-breaking nanocarrier by the modification of iron oxide nanoparticles (IONPs) with a tumor-targeting peptide c(RGDyK) and a hyaluronidase (HAase) on the surface. The yielding nanocomplex, c(RGDyK)-HAase-IONP, targeted the tumor by binding integrin αvß3 and went deeply into the tumors by the degradation of hyaluronic acid (HA), which was highly expressed in the tumor extracellular matrix (ECM). Good biostability and a low pH preferred drug release profile were characterized for c(RGDyK)-HAase-IONP carrying DOX in vitro. c(RGDyK)-HAase-IONP showed an improved tumor-targeting (2.5 times higher) effect after intravenous injection in the MC38 tumor-bearing mice model, as determined by whole-body fluorescence imaging compared to the non-targeted IONPs without HAase. After 5 systemic treatments, c(RGDyK)-HAase-IONP/DOX (5 mg/kg of equivalent dose of DOX) significantly inhibited MC38 tumor growth (22.1 ± 7.4 times relative to the non-treated group). Elevated apoptosis and reduced proliferation in the tumor cell were detected in the c(RGDyK)-HAase-IONP/DOX treated tumors compared to the control groups. Overall, the highly efficient targeted nanocarrier c(RGDyK)-HAase-IONP demonstrated tremendous potency for improving drug delivery and tumor therapy efficacy by targeted degradation of the dense HA barrier in the tumor ECM. We determined that such a tumor stroma-degrading nanosystem was capable of reducing tumor recurrence and drug resistance and could ultimately improve clinical tumor treatment responses.

Three-dimensional imaging for the localization of related anatomical structures during surgery on the internal auditory canal.

BACKGROUND: The Fisch infra-temporal fossa approach (Fisch's method), first proposed in 1970, is commonly used during internal auditory canal (IAC) surgery with an approach that advances through the middle cranial fossa. This study was designed to address the technical difficulties encountered in recognizing and localizing the arcuate eminence with respect to the superior semicircular canal (SSC). METHODS: Forty men and 40 women (18-57 years of age) without space-occupying lesions in the petrous part of the temporal bone were selected for the study. In total, 160 samples were obtained from both sides of the temporal bone. The temporal bone in these 160 samples was scanned using computed tomography, and a three-dimensional coordinate system was established to measure the three-dimensional coordinate values of structures adjacent to the arcuate eminence, the SSC, and the IAC. RESULTS: The results showed that the shape of the arcuate eminence is highly variable. Approximately 23.12% of samples had no obvious arcuate eminence, which prevented the use of Fisch's method to localize the SSC. The arcuate eminence was difficult to identify in 37 samples. CONCLUSIONS: Analysis samples showed that the SSC was located in a fan ring centered at the midpoint of the upper edge of the petrous portion of the temporal bone. The arcuate eminence did not correspond directly with the SSC, as the former was located posterolateral to the latter in 85.83% of samples. The angle between the SSC and the IAC ranged from 0° to 60° degrees, as reported previously by Fisch. However, the angle typically ranged from 10-30° in our study.

Silencing long non-coding RNA MEG8 inhibits the proliferation and induces the ferroptosis of hemangioma endothelial cells by regulating miR-497-5p/NOTCH2 axis.

Even though long non-coding RNA (lncRNA) MEG8 plays vital roles in carcinogenesis of malignances, its roles and mechanisms in hemangioma remain unknown. Therefore, we evaluate the oncogenic roles of MEG8 in hemangioma. Small interfering RNA (siRNA)-mediated depletion of MEG8 inhibited the proliferation and increased MDA level in human hemangioma endothelial cells (HemECs). The inhibitors of ferroptosis (ferrostatin-1 and liproxstatin-1) abolished the MEG8 silence induced cell viability loss. Knockdown of MEG8 increased the miR-497-5p expression and reduced the mRNA and protein levels of NOTCH2. Using a dual-luciferase assay, we confirmed the binding between MEG8 and miR-497-5p, and between the miR-497-5p and 3'UTR of NOTCH2. We further found that silencing MEG8 significantly decreased the expressions of SLC7A11 and GPX4 both in mRNA and protein level and had no effect on the level of AIFM2. Importantly, blocking miR-497-5p abrogated the effects of MEG8 loss on cell viability, MDA level and expression levels of NOTCH2, SLC7A11 and GPX4 in HemECs. Taken together, our results suggested that knockdown of long non-coding RNA MEG8 inhibited the proliferation and induced the ferroptosis of hemangioma endothelial cells by regulating miR-497-5p/NOTCH2 axis.

An Integrin-αvß6/α5ß1-Bitargeted Probe for the SPECT Imaging of Pancreatic Adenocarcinoma in Preclinical and Primary Clinical Studies.

Pancreatic adenocarcinoma (PA) is one of the deadliest human malignancies. However, early detection, prediction of surgical resectability, and prognosis of PA are challenging with current conventional imaging technologies in the clinic. Molecular imaging technologies combined with novel imaging probes could be useful for early detection and accurate staging of PA. Integrin αvß6 and α5ß1 are found to be overexpressed in PA. In this study, integrin αvß6/α5ß1-bitargeted probes 99mTc-HYNIC-isoDGR (99mTc-isoDGR) and 99mTc-HYNIC-PEG4-PisoDGR2 (99mTc-3PisoDGR2) were prepared and evaluated in the BxPC-3 human pancreatic tumor model. Both subcutaneous and in situ BxPC-3 tumors could be clearly visualized by 99mTc-isoDGR nanoScan SPECT/CT imaging with a high ratio of tumor to background. The blocking study with excess nonradioactive peptide showed a significantly reduced tumor uptake, which confirmed the specificity of 99mTc-isoDGR. Biodistribution results confirmed the imaging results. The dimer tracer 99mTc-3PisoDGR2 significantly enhanced tumor uptake compared with 99mTc-isoDGR, and the spontaneous PA lesion in the mouse model could be clearly visualized by 99mTc-3PisoDGR2. The primary clinical study also verified the ability of 99mTc-3PisoDGR2 for detection of PA. Therefore, SPECT/CT imaging using the integrin αvß6/α5ß1-bitargeted 99mTc-3PisoDGR2 provided a potential approach for the noninvasive detection of PA.

Imaging and monitoring HER2 expression in breast cancer during trastuzumab therapy with a peptide probe 99mTc-HYNIC-H10F.

PURPOSE: The novel molecular imaging probe 99mTc-HYNIC-H10F was developed for patient screening and efficacy monitoring of trastuzumab therapy by SPECT imaging of HER2 expression in breast cancer. METHODS: 99mTc-HYNIC-H10F was developed by labeling H10F peptide with 99mTc following an optimized protocol. Biodistribution and SPECT/CT were performed in mouse models bearing HER2-positive SK-BR3 and HER2-negative MDA-MB-231 human breast cancer xenografts, respectively. The treatment response to trastuzumab was monitored and quantified by SPECT/CT in two HER2-positive breast cancer models (SK-BR3 and MDA-MB-361). The preliminary clinical study was performed in two patients with breast cancer. RESULTS: SPECT/CT with 99mTc-HYNIC-H10F showed that the SK-BR3 tumors were clearly visualized, while the signals from MDA-MB-231 tumors were much lower. The tumor uptake of 99mTc-HYNIC-H10F could be blocked by excess unlabeled H10F peptide but not by excess trastuzumab. The growth of two HER2-positive tumors was prominently suppressed at day 11 post-treatment. However, SPECT/CT reflected much earlier therapy response at day 4 post-treatment. The HER2 expression in tumors of breast cancer patients could be detected by 99mTc-HYNIC-H10F SPECT/CT imaging. CONCLUSIONS: 99mTc-HYNIC-H10F specifically accumulates in HER2-positive tumors. Compared with trastuzumab, 99mTc-HYNIC-H10F binds to a different domain of HER2 antigen, providing new opportunities to monitor HER2 expression levels before/during/after trastuzumab treatment for more effective personalized treatment.

Construction and evaluation of hyaluronic acid-based copolymers as a targeted chemotherapy drug carrier for cancer therapy.

Melanoma (MM) is a highly aggressive skin cancer with limited treatment options. Although chemotherapy has been using for advanced melanoma treatment, the lack of targetability, the poor biocompatibility and the severe side effects still hamper the wide applications of chemotherapy agents in MM management. Herein, a biocompatible and biodegradable polymeric hyaluronic acid nanoparticle (HANP) encapsulated with Paclitaxel (PTX) was developed for MM targeted therapy. Our results showed that PTX at 37 ± 2.1% (w/w) was able to be loaded into HANP with over 5 d of stability under physiological conditions. In vitro, HANP/PTX presented hyaluronidase-dependent drug release. Compared to free PTX, HANP/PTX demonstrated a 6-75 times higher growth inhibition in five different cancer cells, while only presenting minimum toxicity to normal cells. After intravenous administration at a 10 mg kg-1 equivalent dose of PTX, HANP/PTX significantly ablated MM tumor growth in a mouse model. As confirmed by 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) imaging, the tumors started to respond to the HANP/PTX as early as 7 d after the initial treatment, which will significantly benefit for personalized treatment. In conclusion, the HANP/PTX nanocomplex demonstrated great promise as a translational nanomedicine for cancer chemotherapy.

Modulation of TRPV4 and BKCa for treatment of brain diseases.

As a member of transient receptor potential family, the transient receptor potential vanilloid 4 (TRPV4) is a kind of nonselective calcium-permeable cation channel, which belongs to non-voltage gated Ca2+ channel. Large-conductance Ca2+-activated K+ channel (BKCa) represents a unique superfamily of Ca2+-activated K+ channel (KCa) that is both voltage and intracellular Ca2+ dependent. Not surprisingly, aberrant function of either TRPV4 or BKCa in neurons has been associated with brain disorders, such as Alzheimer's disease, cerebral ischemia, brain tumor, epilepsy, as well as headache. In these diseases, vascular dysfunction is a common characteristic. Notably, endothelial and smooth muscle TRPV4 can mediate BKCa to regulate cerebral blood flow and pressure. Therefore, in this review, we not only discuss the diverse functions of TRPV4 and BKCa in neurons to integrate relative signaling pathways in the context of cerebral physiological and pathological situations respectively, but also reveal the relationship between TRPV4 and BKCa in regulation of cerebral vascular tone as an etiologic factor. Based on these analyses, this review demonstrates the effective mechanisms of compounds targeting these two channels, which may be potential therapeutic strategies for diseases in the brain.

Ultrathin gold nanowires to enhance radiation therapy.

BACKGROUND: Radiation therapy is a main treatment option for cancer. Due to normal tissue toxicity, radiosensitizers are commonly used to enhance RT. In particular, heavy metal or high-Z materials, such as gold nanoparticles, have been investigated as radiosensitizers. So far, however, the related studies have been focused on spherical gold nanoparticles. In this study, we assessed the potential of ultra-thin gold nanowires as a radiosensitizer, which is the first time. METHODS: Gold nanowires were synthesized by the reduction of HAuCl4 in hexane. The as-synthesized gold nanowires were then coated with a layer of PEGylated phospholipid to be rendered soluble in water. Spherical gold nanoparticles coated with the same phospholipid were also synthesized as a comparison. Gold nanowires and gold nanospheres were first tested in solutions for their ability to enhance radical production under irradiation. They were then incubated with 4T1 cells to assess whether they could elevate cell oxidative stress under irradiation. Lastly, gold nanowires and gold nanoparticles were intratumorally injected into a 4T1 xenograft model, followed by irradiation applied to tumors (3 Gy/per day for three days). Tumor growth was monitored and compared. RESULTS: Our studies showed that gold nanowires are superior to gold nanospheres in enhancing radical production under X-ray radiation. In vitro analysis found that the presence of gold nanowires caused elevated lipid peroxidation and intracellular oxidative stress under radiation. When tested in vivo, gold nanowires plus irradiation led to better tumor suppression than gold nanospheres plus radiation. Moreover, gold nanowires were found to be gradually reduced to shorter nanowires by glutathione, which may benefit fractionated radiation. CONCLUSION: Our studies suggest that gold nanowires are a promising type of radiosensitizer that can be safely injected into tumors to enhance radiotherapy. While the current study was conducted in a breast cancer model, the approach can be extended to the treatment of other cancer types.

Barium tungstate nanoparticles to enhance radiation therapy against cancer.

High-Z nanoparticles have emerged as a novel type of radiosensitizers due to their relatively large X-ray cross-section and ability to enhance radical production under irradiation. Recently, CaWO4 nanoparticles have been prepared and their potential as a radiosensitizer has been demonstrated. Herein, we investigated BaWO4 nanoparticles as a novel type of alkaline-earth metal tungstate radiosensitizer for radiotherapy (RT). We synthesized BaWO4 nanoparticles using hydrothermal reaction and coated them with polyvinylpyrrolidone (PVP). We found that BaWO4 nanoparticles could more efficiently enhance hydroxyl radical production under irradiation than CaWO4 nanoparticles. When tested in vitro, BaWO4 nanoparticles showed lower toxicity than CaWO4 nanoparticles in the absence of irradiation, but induced more significant oxidative stress under irradiation. When tested in vivo, BaWO4 nanoparticles led to more efficient tumor inhibition without causing systemic toxicity. Overall, our results suggest that BaWO4 nanoparticles can efficiently enhance RT and hold great potential as a novel type of radiosensitizing agent.

High-Dose RAI Therapy Justified by Pathological N1a Disease Revealed by Prophylactic Central Neck Dissection for cN0 Papillary Thyroid Cancer Patients: Is it Superior to Low-Dose RAI Therapy?

OBJECTIVE: One of the presumed advantages of prophylactic central neck dissection (pCND) is offering staging basis for more aggressive radioactive iodine (RAI) therapy, which postulates the necessity of high dose for treatment efficacy. The present study aims to compare the effectiveness between low-dose and high-dose RAI in a select cohort of cN0 papillary thyroid cancer (PTC) patients with pathological N1a (pN1a) disease revealed by pCND in terms of ablation rate and response to therapy. The frequency of short-term adverse effects between the two groups was also compared. PATIENTS AND METHODS: From January 2014 to April 2016, cN0 PTC patients with pN1a disease revealed by pCND in our hospital were retrospectively reviewed. Patients with other indications for high-dose RAI, such as the presence of extrathyroidal extension, vascular invasion or suspicions of distant metastasis, were excluded. For the included patients, high dose (3700 MBq) was administered between January 2014 and August 2015 and low dose (1110 MBq) between August 2015 and April 2016. Ablation assessment was performed 6 months after RAI therapy. Response evaluation after RAI therapy was performed after 46.3 ± 9.5 months for high-dose group and 29.1 ± 2.6 months for low-dose group. All patients were also evaluated for short-term adverse effects 24 and 72 hours after RAI administration. RESULTS: A total of 84 patients were enrolled. Among them, 42 were in the high-dose group and the other 42 in the low-dose group. There was no significant difference in ablation rate (P = 0.7707) and response to RAI therapy (P = 0.6454) between the two groups. Twenty-four hours after RAI administration, neck pain and swelling (33.3% VS. 11.9%; P = 0.0372) and gastrointestinal discomfort (45.2% vs. 21.4%; P = 0.0373) were significantly more frequent in the high-dose group. CONCLUSION: High-dose RAI therapy, with higher frequency of short-term adverse effects, appears to be not superior to low-dose RAI therapy for cN0 PTC patients with pN1a disease revealed by pCND to achieve better response to therapy. Further randomized studies with larger series of patients and longer follow-up duration, especially with the low-dose group, are needed to validate our results.

The CXCL12-CXCR4 axis promotes migration, invasiveness, and EMT in human papillary thyroid carcinoma B-CPAP cells via NF-κB signaling.

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy involving local and distant metastasis. It is known that CXC chemokine ligand 12 (CXCL12) interacts specifically with CXC chemokine receptor 4 (CXCR4) to guide the migration of PTC cells. However, the signaling pathway downstream of the CXCL12-CXCR4 axis in PTC is not fully understood. In the present study, high expression of CXCR4 was detected in 38 out of 82 specimens of PTC, and the expression level of CXCR4 significantly correlated with the stage of PTC. Additionally, the roles of the CXCL12-CXCR4 axis in the migration, invasion, and epithelial-mesenchymal transition (EMT) of B-CPAP cells were investigated in vitro. The motility and invasiveness were significantly enhanced in CXCR4-overexpressing B-CPAP cells with CXCL12 treatment. Moreover, the CXCL12-CXCR4 axis promoted the EMT process, as evidenced by a decreased level of E-cadherin and increased expressions of N-cadherin and vimentin. Furthermore, the CXCL12-CXCR4 axis activated the nuclear factor kappa-B (NF-κB) signaling pathway, whereas BAY11-7082, an IκB phosphorylation inhibitor, counteracted CXCL12-CXCR4-induced migration, invasion, and EMT processes in B-CPAP cells. In conclusion, the CXCL12-CXCR4 axis promotes the migration, invasion, and EMT processes in B-CPAP cells, at least partly, by activating the NF-κB signaling pathway.

Photosensitizer-Encapsulated Ferritins Mediate Photodynamic Therapy against Cancer-Associated Fibroblasts and Improve Tumor Accumulation of Nanoparticles.

Nanoparticles have been widely tested as drug delivery carriers or imaging agents, largely because of their ability to selectively accumulate in tumors through the enhanced permeability and retention (EPR) effect. However, studies show that many tumors afford a less efficient EPR effect and that many nanoparticles are trapped in the perivascular region after extravasation and barely migrate into tumor centers. This is to a large degree attributed to the dense tumor extracellular matrix (ECM), which functions as a physical barrier to prevent efficient nanoparticle extravasation and diffusion. In this study, we report a photodynamic therapy (PDT) approach to enhance tumor uptake of nanoparticles. Briefly, we encapsulate ZnF16Pc, a photosensitizer, into ferritin nanocages, and then conjugate to the surface of the ferritin a single chain viable fragment (scFv) sequence specific to fibroblast activation protein (FAP). FAP is a plasma surface protein widely upregulated in cancer-associated fibroblasts (CAFs), which is a major source of the ECM fiber components. We found that the scFv-conjugated and ZnF16Pc-loaded ferritin nanoparticles (scFv-Z@FRT) can mediate efficient and selective PDT, leading to eradication of CAFs in tumors. When tested in bilateral 4T1 tumor models, we found that the tumor accumulation of serum albumin (BSA), 10 nm quantum dots (QDs), and 50 nm QDs was increased by 2-, 3.5-, and 18-fold after scFv-Z@FRT mediated PDT. Our studies suggest a novel and safe method to enhance the delivery of nanoparticles to tumors.

Multifunctional Molecular Beacon Micelles for Intracellular mRNA Imaging and Synergistic Therapy in Multidrug-Resistant Cancer Cells.

Multidrug resistance (MDR) resulting from overexpression of P-glycoprotein (Pgp) transporters increases the drug efflux and thereby limits the chemotherapeutic efficacy. It is desirable to administer both an MDR1 gene silencer and a chemotherapeutic agent in a sequential way to generate a synergistic therapeutic effect in multidrug-resistant cancer cells. Herein, we rationally designed an anti-MDR1 molecular beacon (MB)-based micelle (a-MBM) nanosystem, which is composed of a diacyllipid core densely packed with an MB corona. One of Pgp-transportable agents, doxorubicin (DOX), was encapsulated in the hydrophobic core of the micelle and in the stem sequence of MB. The a-MBM-DOX nanosystem showed an efficient self-delivery, enhanced enzymatic stability, excellent target selectivity, and high drug-loading capacity. With its relatively high enzymatic stability, a-MBM-DOX initially facilitated intracellular MDR1 mRNA imaging to distinguish multidrug-resistant and non-multidrug-resistant cells and subsequently downregulated the MDR1 gene expression owing to an antisense effect. After that, the MB corona was degraded, destroying the micellar nanostructure and releasing DOX, which resulted in a high accumulation of DOX in OVCAR8/ADR cells and a high chemotherapeutic efficacy owing to successful restoration of drug sensitivity. This micelle approach has the potential for both visualizing MDR1 mRNA and overcoming MDR in a sequential and synergistic way.

Stable Evans Blue Derived Exendin-4 Peptide for Type 2 Diabetes Treatment.

In the treatment of type 2 diabetes mellitus, it is very important to develop therapeutics with prolonged circulation half-life. Exendin-4 is a glucagon like peptide-1 receptor (GLP-1R) agonist that has been modified in different ways for imaging insulinoma and for treating type-2 diabetes. In this work, we synthesized a maleimide derivative of truncated Evans blue dye (MEB-C3-Mal) to conjugate with (Cys(40))exendin-4 to obtain a highly stable MEB-C3-(Cys(40))exendin-4 (denoted as Abextide II). Through in situ binding with endogenous albumin, Abextide II lowers blood glucose level and prolongs the hypoglycemic effect in a type 2 diabetes mouse model more than the FDA approved Albiglutide.

99mTc-3PRGD2 SPECT to monitor early response to neoadjuvant chemotherapy in stage II and III breast cancer.

PURPOSE: Monitoring of response to neoadjuvant chemotherapy (NCT) is important for optimal management of patients with breast cancer. (99m)Tc-3PRGD2 SPECT is a newly developed imaging modality for evaluating tumor vascular status. In this study, we investigated the application of (99m)Tc-3PRGD2 SPECT in evaluating therapy response to NCT in patients with stage II or III breast cancer. METHODS: Thirty-three patients were scheduled to undergo (99m)Tc-3PRGD2 SPECT at baseline, after the first and second cycle of NCT. Four patients had extremely low (99m)Tc-3PRGD2 uptake at baseline, and were not included in the subsequent studies. Changes in tumor to nontumor (T/N) ratio were compared with pathological tumor responses classified using the residual cancer burden system. Receiver operator characteristic analysis was used to compare the power to identify responders between the end of the first and the end of the second cycle of NCT. The impact of breast cancer subtype on (99m)Tc-3PRGD2 uptake was evaluated. The correlation between (99m)Tc-3PRGD2 uptake and pathological tumor response was also evaluated in each breast cancer subtype. RESULTS: Surgery was performed after four cycles of NCT and pathological analysis revealed 18 responders and 15 nonresponders. In patients with clearly visible (99m)Tc-3PRGD2 uptake at baseline, the sensitivity, specificity, and negative predictive value of (99m)Tc-3PRGD2 SPECT were 86.7 %, 85.7 % and 86.7 % after the first cycle of NCT, and 92.9 %, 93.3 % and 93.3 % after the second cycle, respectively. Among these patients, the HER-2-positive group demonstrated both higher T/N ratios and a greater change in T/N ratio than patients with other breast cancer subtypes (P < 0.05). A strong correlation was found between changes in T/N ratio and pathological tumor response in the HER-2-positive group (P < 0.03). CONCLUSION: (99m)Tc-3PRGD2 SPECT seems to be useful for determining the pathological tumor response in patients with stage II or III breast cancer undergoing NCT, especially those with the HER-2-positive subtype.

The diagnostic role of 99mTc-dual receptor targeted probe and targeted peptide bombesin (RGD-BBN) SPET/CT in the detection of malignant and benign breast tumors and axillary lymph nodes compared to ultrasound.

OBJECTIVE: This study aimed to explore the diagnostic role of a new dual receptor-targeted probe, integrin ανß3 and gastrin releasing peptide receptor (GRPR) targeted peptide Glu-c(RGDyK)-bombesin (RGD-BBN) labeled with technetium-99m ((99m)Tc-RGD-BBN), using single photon emission tomography/computed tomography (SPET/CT) in the detection of breast tumor in comparison to ultrasound (US). SUBJECTS AND METHODS: One hundred and twenty six female patients with suspicious breast lesions who had already been scheduled for biopsy or surgery were enrolled in this study. All patients had previously underwent breast US and (99m)Tc-RGD-BBN SPET/CT. The US findings were evaluated according to the breast imaging report and the data system (BI-RADS). Technetium-99m-RGD-BBN SPET/CT images were interpreted independently by two experienced nuclear medicine physicians. A final diagnosis was made by histopathology of the specimens. A total of 130 lesions, 77 malignant and 53 benign lesions were ascertained. One hundred and twelve breast lesions, 69 malignant and 43 benign lesions were above 10mm in diameter and 18 breast lesions (8 malignant lesions and 10 benign lesions) were below 10mm. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of (99m)Tc-RGD-BBN SPET/CT and US for breast lesions were 93.5% vs. 81.8% (P<0.05), 79.2% vs. 75.5% (P>0.05), 86.7% vs. 82.9% (P>0.05), 89.4% vs. 74.1% (P<0.05) and 87.7% vs. 79.2% (P>0.05). Technetium-99m-RGD-BBN SPET/CT detected all lesions ≥10mm and US only detected 57 (P<0.05). In malignant lesions <10mm, US was superior than (99m)Tc-RGD-BBN SPET/CT (75.0% vs. 37.5%, P<0.05). There was no significant difference between the two methods no matter the size of the benign lesions. The overall sensitivity and specificity of (99m)Tc-RGD-BBN SPET/CT and US for axillae lymph nodes were 87.5% vs. 71.9% (P<0.05) and 77.6% vs. 68.9% (P>0.05), respectively. For the metastatic lymph nodes of <10mm, the sensitivity of (99m)Tc-RGD-BBN SPET/CT and of US was 88.5% and 72.1% respectively (P<0.05). Statistical analysis was not performed due to the small number of metastatic lesions of <10mm. The specificity of (99m)Tc-RGD-BBN SPET/CT and of US was not different, no matter the size of the axilla lymph nodes that had no metastases (P>0.05). Technetium-99m-RGD-BBN SPET/CT had higher sensitivity and NPV than US in detecting primary breast tumors and axilla lymph nodes and it also showed an advantage in distance metastatic lesions detection. On the contrary, specificity and PPV of the two methods were not different. CONCLUSION: Technetium-99m-RGD-BBN SPET/CT cannot totally replace US in the detection of primary breast cancer and axillary lymph nodes metastases. It can be used as an additional imaging tool of eliminating the necessity of surgical biopsy and histopathologic examination because of its high NPV.

Diagnostic value of (99m)Tc-3PRGD2 scintimammography for differentiation of malignant from benign breast lesions: Comparison of visual and semi-quantitative analysis.

OBJECTIVE: To compare the diagnostic value of visual and semi-quantitative analysis of technetium-99m-poly-ethylene glycol, 4-arginine-glycine-aspartic acid ((99m)Tc-3PRGD2) scintimammography (SMG) for better differentiation of benign from malignant breast masses, and also investigate the incremental role of semi-quantitative index of SMG. SUBJECTS AND METHODS: A total of 72 patients with breast lesions were included in the study. Technetium-99m-3PRGD2 SMG was performed with single photon emission computed tomography (SPET) at 60 min after intravenous injection of 749 ± 86MBq of the radiotracer. Images were evaluated by visual interpretation and semi-quantitative indices of tumor to non-tumor (T/N) ratios, which were compared with pathology results. Receiver operating characteristics (ROC) curve analyses were performed to determine the optimal visual grade, to calculate cut-off values of semi-quantitative indices, and to compare visual and semi-quantitative diagnostic values. RESULTS: Among the 72 patients, 89 lesions were confirmed by histopathology after fine needle aspiration biopsy or surgery, 48 malignant and 41 benign lesions. The mean T/N ratio of (99m)Tc-3PRGD2 SMG in malignant lesions was significantly higher than that in benign lesions (P<0.05). When grade 2 of the disease was used as cut-off value for the detection of primary breast cancer, the sensitivity, specificity and accuracy were 81.3%, 70.7%, and 76.4%, respectively. When a T/N ratio of 2.01 was used as cut-off value, the sensitivity, specificity and accuracy were 79.2%, 75.6%, and 77.5%, respectively. According to ROC analysis, the area under the curve for semi-quantitative analysis was higher than that for visual analysis, but the statistical difference was not significant (P=0.372). Compared with visual analysis or semi-quantitative analysis alone, the sensitivity, specificity and accuracy of visual analysis combined with semi-quantitative analysis in diagnosing primary breast cancer were higher, being: 87.5%, 82.9%, and 85.4%, respectively. The area under the curve was 0.891. CONCLUSION: Results of the present study suggest that the semi-quantitative and visual analysis statistically showed similar results. The semi-quantitative analysis provided incremental value additive to visual analysis of (99m)Tc-3PRGD2 SMG for the detection of breast cancer. It seems from our results that, when the tumor was located in the medial part of the breast, the semi-quantitative analysis gave better diagnostic results.

(99)mTc-3PRGD2 scintimammography in palpable and nonpalpable breast lesions.

The aim of this study was to explore the diagnostic performance of 99mTc-3(poly-(ethylene glycol),PEG)4-RGD2 (99mTc-3PRGD2) scintimammography (SMM) in patients with either palpable or nonpalpable breast lesions and compare SMM to mammography to assess the possible incremental value of SMM in breast cancer detection. We also investigated the αvß3 expression in malignant and benign breast lesions. Ninety-four patients with 110 lesions were included in this study. Mammograms were evaluated according to the Breast Imaging Reporting and Data System (BI-RADS) by a specialized imaging radiologist. Prone SMM was performed 1 hour after injection of 99mTc-3PRGD2. Scintigraphic images were interpreted independently by two experienced nuclear medicine physicians using a three-point system, and the kappa value was calculated to determine the interreader agreement. The McNemar test was used to compare SMM and mammography with respect to sensitivity, specificity, and accuracy. Diagnostic values for breast cancer detection were evaluated for each lesion. Immunohistochemistry was performed to evaluate integrin αvß3 expression. Histopathology revealed 46 malignant lesions and 64 benign lesions. The overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SMM were 83%, 73%, 77%, 69%, and 85%, respectively. The kappa value between the two reviewers was 0.63. The diagnostic values of SMM were higher than those of mammography in evaluating overall breast lesions. A sensitivity of 91% was achieved when SMM and mammography results were combined with 60% of all false-negative mammography findings classified as true-positive results by SMM. Integrin αvß3 expression was positively identified using SMM imaging. SMM is a promising tool to avoid unnecessary biopsies when used in addition to mammography and can be used to image αvß3 expression in breast cancer with good image quality.