Preclinical evaluation of a novel EGFR&c-Met bispecific near infrared probe for visualization of esophageal cancer and metastatic lymph nodes.

PURPOSE: This study aimed to establish a near infrared fluorescent (NIRF) probe based on an EGFR&c-Met bispecific antibody for visualization of esophageal cancer (EC) and metastatic lymph nodes (mLNs). METHODS: EGFR and c-Met expression were assessed by immunohistochemistry. EGFR&c-Met bispecific antibody EMB01 was labeled with IRDye800cw. The binding of EMB01-IR800 was assessed by enzyme linked immunosorbent assay, flow cytometry, and immunofluorescence. Subcutaneous tumors, orthotopic tumors, and patient-derived xenograft (PDX) were established for in vivo fluorescent imaging. PDX models using lymph nodes with or without metastasis were constructed to assess the performance of EMB01-IR800 in differential diagnosis of lymph nodes. RESULTS: The prevalence of overexpressing EGFR or c-Met was significantly higher than single marker either in EC or corresponding mLNs. The bispecific probe EMB01-IR800 was successfully synthesized, with strong binding affinity. EMB01-IR800 showed strong cellular binding to both Kyse30 (EGFR overexpressing) and OE33 (c-Met overexpressing) cells. In vivo fluorescent imaging showed prominent EMB01-IR800 uptake in either Kyse30 or OE33 subcutaneous tumors. Likewise, EMB01-IR800 exhibited superior tumor enrichment in both thoracic orthotopic esophageal squamous cell carcinoma and abdominal orthotopic esophageal adenocarcinoma models. Moreover, EMB01-IR800 produced significantly higher fluorescence in patient-derived mLNs than in benign lymph nodes. CONCLUSION: This study demonstrated the complementary overexpression of EGFR and c-Met in EC. Compared to single-target probes, the EGFR&c-Met bispecific NIRF probe can efficiently depict heterogeneous esophageal tumors and mLNs, which greatly increased the sensitivity of tumor and mLN identification.

Novel STING-targeted PET radiotracer for alert and therapeutic evaluation of acute lung injury.

Acute lung injury (ALI), as a common clinical emergency, is pulmonary edema and diffuse lung infiltration caused by inflammation. The lack of non-invasive alert strategy, resulting in failure to carry out preventive treatment, means high mortality and poor prognosis. Stimulator of interferon genes (STING) is a key molecular biomarker of innate immunity in response to inflammation, but there is still a lack of STING-targeted strategy. In this study, a novel STING-targeted PET tracer, [18F]FBTA, was labeled with high radiochemical yield (79.7 ± 4.3%) and molar activity (32.5 ± 2.9 GBq/µmol). We confirmed that [18F]FBTA has a strong STING binding affinity (Kd = 26.86 ± 6.79 nmol/L) and can be used for PET imaging in ALI mice to alert early lung inflammation and to assess the efficacy of drug therapy. Our STING-targeted strategy also reveals that [18F]FBTA can trace ALI before reaching the computed tomography (CT) diagnostic criteria, and demonstrates its better specificity and distribution than [18F]fluorodeoxyglucose ([18F]FDG).

Inhibition of JNK/c-Jun-ATF2 Overcomes Cisplatin Resistance in Liver Cancer through down-Regulating Galectin-1.

Due to drug resistance, the clinical response to cisplatin (CDDP) from patients with liver cancer is unsatisfactory. The alleviation or overcoming of CDDP resistance is an urgent problem to be solved in clinics. Tumor cells rapidly change signal pathways to mediate drug resistance under drug exposure. Here, multiple phosphor-kinase assays were performed and c-Jun N-terminal kinase (JNK) was activated in liver cancer cells treated with CDDP. The high activity of the JNK promotes poor progression and mediates cisplatin resistance in liver cancer, leading to a poor prognosis of liver cancer. Mechanistically, the highly activated JNK phosphorylated c-Jun and ATF2 formed a heterodimer to upregulate the expression of Galectin-1, leading to promoting cisplatin resistance in liver cancer. Importantly, we simulated the clinical evolution of drug resistance in liver cancer by continuous CDDP administration in vivo. In vivo bioluminescence imaging showed the activity of JNK gradually increased during this process. Moreover, the inhibition of JNK activity by small molecular or genetic inhibitors enhanced DNA damage and overcame CDDP resistance in vitro and in vivo. Collectively, our results underline that the high activity of JNK/c-Jun-ATF2/Galectin-1 mediates cisplatin resistance in liver cancer and provides an optional scheme for dynamic monitoring of molecular activity in vivo.

Identification of a CEACAM5 targeted nanobody for positron emission tomography imaging and near-infrared fluorescence imaging of colorectal cancer.

PURPOSE: Here, we aim to identify a CEACAM5-targeted nanobody and demonstrate its application in positron emission tomography (PET) imaging and near-infrared (NIR) fluorescence imaging in colorectal cancer (CRC). METHODS: Immunohistochemistry was applied to verify CEACAM5 expression in CRC and metastatic lymph nodes (mLNs). CEACAM5-targeted nanobodies were obtained by immunization of human CEACAM5 protein in a dromedary, followed by several rounds of phage screenings. Immunofluorescence staining and flow cytometry was carried out to determine the binding affinity of the nanobodies. The nanobodies were radiolabeled by coupling 18F-SFB for PET imaging of CRC subcutaneous xenografts and lymph node metastasis (LNM). IRDye800CW (IR800) were conjugated to form NIR probes for NIR imaging in CRC subcutaneous models. RESULTS: CEACAM5 was overexpressed in either human CRC tissues or mLNs. A CEACAM5 targeted nanobody, Nb41 was successfully generated, with excellent in vitro binding properties. Incorporation of albumin binding domain (ABD) did not affect the affinity of Nb41. In vivo imaging showed that both 18F-FB-Nb41 and 18F-FB-Nb41-ABD showed obvious accumulation in the tumor. Due to the longer retention in the blood, 18F-FB-Nb41-ABD enrichment in tumors was significantly delayed but higher compared to 18F-FB-Nb41. Both 18F-FB-Nb41 and 18F-FB-Nb41-ABD showed prominent LNM enrichment. Similarly, the IR800-conjugated nanobodies Nb41-IR800 and Nb41-ABD-IR800 exhibited superior imaging effects in subcutaneous models, while Nb41-ABD-IR800 exhibited higher fluorescence intensity in the tumor accompanied with a remarkedly delay compared to Nb41-IR800. CONCLUSION: Collectively, we presented the identification and in vivo validation of a CEACAM5-targeted nanobody and a fused nanobody with an ABD, which enabled to the non-invasive visualization of malignancy of CRC using PET imaging and NIR imaging in subcutaneous models as well as LNM models.

pH-sensitive molybdenum (Mo)-based polyoxometalate nanoclusters have therapeutic efficacy in inflammatory bowel disease by counteracting ferroptosis.

Current therapeutic drugs for ulcerative colitis (UC) remained inadequate due to drug dependence and unacceptable adverse events. Reactive oxygen species (ROS) played a critical role in the occurrence and development of UC, which most likely benefited from treatment in scavenging ROS. In this study, we developed a pH-sensitive molybdenum-based polyoxometalate (POM) nanocluster, which might contribute to site specific colonic delivery and enhance systemic efficacy of UC treatment. Our results demonstrated that POM displayed robust ROS scavenging ability in vitro. POM could significantly alleviate the enteric symptoms and inflammatory indicators in DSS-induced UC mouse models. Flow cytometry showed an effective diminishment of macrophages, neutrophils and T cells infiltration after POM administration in UC models. Also, for the first time, we demonstrated that POM interfered with metabolic pathway associated to oxidative stress and partially improved the abnormal production of intestinal metabolites in UC to some extent. Benefiting from the ROS scavenging ability, POM attenuated ferroptosis in DSS induced UC, as evidenced by increase of GSH, down-expression of GPX4 and improvement in mitochondrial morphological changes. Meanwhile, there were no side effects on normal tissues. Thus, our powerful therapeutic effects pioneered the application of POM for safer and more effective POM-based UC therapy.

Arsenic-Loaded Biomimetic Iron Oxide Nanoparticles for Enhanced Ferroptosis-Inducing Therapy of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) has a poor response to most available systemic therapies due to intrinsic or acquired resistance to apoptosis. Ferroptosis-based therapy is expected to circumvent those limitations. Therefore, the rational design of ferroptosis-based therapies with targeted delivery of ferroptosis inducers for HCC is in need. In this study, we found that arsenic trioxide (ATO) can efficiently induce ferroptosis in HCC cells, and this effect could be reversed by the iron chelator deferoxamine. On this basis, a drug delivery system was constructed to enhance the therapeutic efficacy of ATO by camouflaging ATO-loaded magnetic nanoparticles (Fe3O4) with HCC cell membranes, termed AFN@CM. After AFN@CM treatment, glutathione peroxidase 4 was strongly inhibited and intracellular lipid peroxide species were significantly increased in HCC cells. In addition, enhanced ferroptosis and tumor suppression were observed both in vitro and in vivo. The bio-safety of AFN@CM was also demonstrated by the in vivo toxicity evaluation. In addition, benefiting from the cell membrane coating, AFN@CM showed enhanced accumulation at tumor sites and achieved continuous tumor elimination in the mouse model. In conclusion, AFN@CM exhibited satisfactory therapeutic efficacy in the treatment of HCC and provided a desirable ferroptosis-based strategy for safe and reliable HCC therapeutics.

Exploration and validation of a combined immune and metabolism gene signature for prognosis prediction of colorectal cancer.

Background: Colorectal cancer (CRC) is still one of the most frequently diagnosed malignancy around the world. The complex etiology and high heterogeneity of CRC necessitates the identification of new reliable signature to identify different tumor prognosis, which may help more precise understanding of the molecular properties of CRC and identify the appropriate treatment for CRC patients. In this study, we aimed to identify a combined immune and metabolism gene signature for prognosis prediction of CRC from large volume of CRC transcriptional data. Methods: Gene expression profiling and clinical data of HCC samples was retrieved from the from public datasets. IRGs and MRGs were identified from differential expression analysis. Univariate and multivariate Cox regression analysis were applied to establish the prognostic metabolism-immune status-related signature. Kaplan-Meier survival and receiver operating characteristic (ROC) curves were generated for diagnostic efficacy estimation. Real-time polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry (IHC) was conducted to verified the expression of key genes in CRC cells and tissues. Results: A gene signature comprising four genes (including two IRGs and two MRGs) were identified and verified, with superior predictive performance in discriminating the overall survival (OS) of high-risk and low-risk compared to existing signatures. A prognostic nomogram based on the four-gene signature exhibited a best predictive performance, which enabled the prognosis prediction of CRC patients. The hub gene ESM1 related to CRC were selected via the machine learning and prognostic analysis. RT-PCR, Western blot and IHC indicated that ESM1 was high expressed in tumor than normal with superior predictive performance of CRC survival. Conclusions: A novel combined MRGs and IRGs-related prognostic signature that could stratify CRC patients into low-and high- risk groups of unfavorable outcomes for survival, was identified and verified. This might help, to some extent, to individualized treatment and prognosis assessment of CRC patients. Similarly, the mining of key genes provides a new perspective to explore the molecular mechanisms and targeted therapies of CRC.

Identification of an IGF2BP2-Targeted Peptide for Near-Infrared Imaging of Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies globally. Peptide-based tumor-targeted imaging is critical for ESCC imaging. In this study, we aim to identify a peptide-targeting IGF2BP2 that specifically binds to human ESCC for near-infrared imaging of esophageal cancer. Applying phage display techniques, we identified a peptide target for IGF2BP2 which was confirmed to be highly expressed in ESCC cell lines or tumor tissue and may serve as an imaging target for ESCC. We conjugated the peptide to the NIRF group, Cy5, and further evaluated the targeting efficacy of the probe at a cellular level and in animal tumor models. The Cy5 conjugated peptide (P12-Cy5) showed a high binding affinity to human ESCC cells in vitro. In vivo, optical imaging also validated the tumor-targeting ability of P12-Cy5 in KYSE-30-bearing subcutaneous ESCC tumor models. Furthermore, the results of biodistribution showed a significantly higher fluorescence intensity in tumors compared to scrambled peptide, which is consistent with in vivo observations. In summary, an IGF2BP2-targeted peptide was successfully identified. In vitro and in vivo experiments confirmed that P12-Cy5 has high affinity, specificity and tumor-targeting properties. Thus, P12-Cy5 is a prospective NIR probe for the imaging of ESCC.

The Prognostic Value of Microvascular Density in Early Postoperative Recurrence and Metastasis of T1 Esophageal Squamous Cell Carcinoma.

OBJECTIVE: To identify the relation of microvascular density (MVD) to the early postoperative recurrence and metastasis of T1 esophageal squamous cell carcinoma, and to determine whether MVD could be a prognostic predictor of esophageal squamous cell carcinoma. METHODS: Patients with T1 esophageal squamous cell carcinoma were enrolled. Immunohistochemistry with primary antibody against CD-34 was performed to count MVD. ROC curve was plotted and appropriate cutoff value was determined to evaluate the potential power of MVD in predicting early recurrence and metastasis of T1 esophageal squamous cell carcinoma. Survival curves were drawn by the Kaplan-Meier method and significance were tested by the Mantel-Cox test. RESULTS: A total of 37 patients with T1 esophageal squamous cell carcinoma were enrolled. The MVD of T1 esophageal squamous cell carcinoma patients with early metastasis was significantly higher than that of T1 esophageal squamous cell carcinoma patients without early metastasis (65.83±4.39 vs. 42.26±2.34, p<0.001). MVD was available in distinguishing whether patients with early esophageal are prone to postoperative recurrence or metastasis (AUC=0.861; 95% CI 0.738-0.984, p<0.001), with 88.89% sensitivity and 68.42% specificity of MVD being obtained when the cut-off is 44.5. Kaplan-Meier survival curves showed that patients with a higher MVD had a lower survival (37.35 months) compared with those with low MVD (40.79 months) (p<0.05). CONCLUSIONS: MVD could be a promising indicator for early postoperative recurrence and metastasis of T1 esophageal squamous cell carcinoma and the prognosis of these patients.

Dissecting a hypoxia-related angiogenic gene signature for predicting prognosis and immune status in hepatocellular carcinoma.

Background: Hypoxia and angiogenesis, as prominent characteristics of malignant tumors, are implicated in the progression of hepatocellular carcinoma (HCC). However, the role of hypoxia in the angiogenesis of liver cancer is unclear. Therefore, we explored the regulatory mechanisms of hypoxia-related angiogenic genes (HRAGs) and the relationship between these genes and the prognosis of HCC. Methods: The transcriptomic and clinical data of HCC samples were downloaded from public datasets, followed by identification of hypoxia- and angiogenesis-related genes in the database. A gene signature model was constructed based on univariate and multivariate Cox regression analyses, and validated in independent cohorts. Kaplan-Meier survival and time-dependent receiver operating characteristic (ROC) curves were generated to evaluate the model's predictive capability. Gene set enrichment analysis (GSEA) was performed to explore signaling pathways regulated by the gene signature. Furthermore, the relationships among gene signature, immune status, and response to anti-angiogenesis agents and immune checkpoint blockade (ICB) were analyzed. Results: The prognostic model was based on three HRAGs (ANGPT2, SERPINE1 and SPP1). The model accurately predicted that low-risk patients would have longer overall survival than high-risk patients, consistent with findings in other cohorts. GSEA indicated that high-risk group membership was significantly associated with hypoxia, angiogenesis, the epithelial-mesenchymal transition, and activity in immune-related pathways. The high-risk group also had more immunosuppressive cells and higher expression of immune checkpoints such as PD-1 and PD-L1. Conversely, the low-risk group had a better response to anti-angiogenesis and ICB therapy. Conclusions: The gene signature based on HRAGs was predictive of prognosis and provided an immunological perspective that will facilitate the development of personalized therapies.

Early Diagnosis of Murine Sepsis-Associated Encephalopathy Using Dynamic PET/CT Imaging and Multiparametric MRI.

PURPOSE: Early diagnosis of sepsis-associated encephalopathy (SAE) is essential for the treatment and prognosis of septic patients. Static PET and MRI have shown promise for early diagnosis, while pharmacokinetic parameters from dynamic PET may provide better quantification for SAE. This study aims to compare the performance of dynamic 2-deoxy-2-[18F]fluoro-D-glucose ([18F]F-FDG) PET and multiparametric MRI in early imaging SAE with a view to providing guidance for the early diagnosis of SAE. PROCEDURES: Dynamic [18F]F-FDG-PET/CT scans and multiparametric MRI were performed in SAE mice induced by LPS. Standardized uptake value (SUV) was measured in static scan images and [18F]F-FDG pharmacokinetic parameters were analyzed with two-tissue compartment model and Patlak plot. MRI relative signal intensity (rT1) derived from T1-weighted images (pre and post contrast) and 4 parameters originating from diffusion-weighted data were measured. RESULTS: Both SUV and dephosphorylation rate constant (k4) increased in SAE model as early as 6 h post sepsis induction, while k4 increased with the relative value (SAE/normal) significantly stronger than that of SUV. Moreover, the net influx constant (Ki) showed significant decrease in SAE as early as 6 h compared with normal mice. Increased signal intensity was identified in T1-weighted contrast enhanced images and rT1 value increased at 12 h post induction. Diffusion tensor imaging (DTI) revealed fractional anisotropy (FA) decreased at 12 h and 24 h in external capsule (ec) and declined axial diffusivity (AD) was shown in white matter at 24 h. CONCLUSIONS: The dynamic PET (k4) was more sensitive than static PET (SUV) for early diagnosis of SAE and declined Ki was firstly found in murine SAE, which indicated the advantage of dynamic PET/CT in early detection and differential diagnosis of SAE. While MRI has a higher soft tissue resolution than PET/CT and can classify more subtle brain areas, the comprehensive utilization of the two modalities is helpful for managing SAE.

NIR-II Navigation with an EGFR-Targeted Probe Improves Imaging Resolution and Sensitivity of Detecting Micrometastases in Esophageal Squamous Cell Carcinoma Xenograft Models.

The survival rate of esophageal squamous carcinoma (ESCC) after surgical resection is estimated to be only 30.3% due to the difficulty in identifying microinfiltration and subtle metastases. In this study, we explored the value of near-infrared fluorescence in the second window (NIR-II) using an epidermal growth factor receptor (EGFR)-targeted probe (cetuximab-IR800) for the intraoperative navigation of ESCC in xenograft mouse models. Immunohistochemical results showed that EGFR was aberrantly expressed in 94.49% (120/127) of ESCC tissues and 90.63% (58/64) of metastatic lymph nodes. Western blot results demonstrated that EGFR protein was highly expressed in ESCC cell lines. Flow cytometry data revealed that cetuximab-IR800 showed a stronger binding specificity in EGFR-positive KYSE-30 cells than in A2780 control cells (P < 0.01). In vivo imaging data showed that the ratio of mean fluorescent intensity (MFI) and tumor to background (TBR) was significantly higher in KYSE-30 subcutaneous tumors with the infusion of cetuximab-IR800 than in those with the infusion of IgG1-IR800 (P < 0.05). Surgical navigation with NIR-II imaging showed that the TBR in orthotopic ESCC was significantly higher than that of NIR in the first window (NIR-I) (2.11 ± 0.46 vs 1.58 ± 0.31, P < 0.05), and NIR-II was more sensitive than NIR-I in detecting subcentimeter metastases (94.87% (37/39) vs 58.97% (23/39), P < 0.001). In conclusion, cetuximab-IR800 with high specificity for ESCC was first used in NIR-II surgical navigation. This probe showed better imaging resolution and higher sensitivity in detecting subtle metastases derived from an orthotopic ESCC model than NIR-I, which indicates that NIR-II has promise in guiding precise surgery for ESCC patients.

c-Met-targeted near-infrared fluorescent probe for real-time depiction and dissection of perineural invasion and lymph node metastasis lesions in pancreatic ductal adenocarcinoma xenograft models.

Pancreatic ductal adenocarcinoma (PDAC), a fatal malignant tumour, has a high postoperative recurrence rate, mainly due to the difficulty of discerning occult lesions, including those related to perineural invasion (PNI) and lymph node metastasis (LNM). Cellular mesenchymal-epithelial transition factor (c-Met), an excellent imaging marker, is aberrantly expressed in the majority of PDACs. Thus, we plan to utilize a c-Met-targeted near-infrared fluorescent (NIRF) probe for real-time visualization and dissection of PDAC, and corresponding PNI and LNM lesions. Immunohistochemistry showed c-Met expression in PDAC, PNI and LNM reached 94.3% (100/106), 88.3% (53/60), and 71.4% (25/35), respectively, and its expression in PNI and LNM was significantly correlated with that in primary PDAC (r = 0.66, p < 0.0001 and r = 0.44, p < 0.01, respectively). SHRmAb-IR800 was successfully synthesized using an anti-c-Met antibody and a NIRF dye. The in vitro targeting ability of SHRmAb-IR800 was higher in CFPAC1 cells (c-Met positive) than in Miapaca-2 cells (c-Met negative) (p < 0.05). In vivo NIRF imaging of CFPAC1 subcutaneous tumours demonstrated higher accumulation of SHRmAb-IR800 than the control probe (p < 0.05). The signal-to-background ratio (TBR) of an orthotopic PDAC tumour was 3.38 ± 0.46, and imaging with SHRmAb-IR800 facilitated the resection of metastatic lesions with sensitivity and specificity values of 93.3% (56/60) and 87.1% (27/31), respectively. Furthermore, tiny PNI and LNM lesions in xenograft models were detected by NIRF imaging, with TBRs measuring 2.59 ± 0.19 and 2.88 ± 0.72, respectively. Therefore, the clinical translation of this probe might shed new light on NIRF-guided pancreatectomy and improve the surgical prognosis of PDAC patients.

Integrin α6-Targeted Magnetic Resonance Imaging of Hepatocellular Carcinoma in Mice.

PURPOSE: Magnetic resonance imaging (MRI) has a high spatial resolution for detecting hepatocellular carcinoma (HCC). Integrin α6 has emerged as a diagnostic and prognostic biomarker of HCC. Here, we developed the MR contrast agent RWY-dL-(Gd-DOTA)4 based on the integrin α6-targeted RWY peptide that we previously identified to detect HCC. PROCEDURES: Contrast-enhanced MRI was carried out to evaluate the use of RWY-dL-(Gd-DOTA)4 to detect HCC lesions in subcutaneous and diethylnitrosamine (DEN)-induced HCC mouse models. RESULTS: Enhancement MR signals were observed in HCC-LM3 subcutaneous liver tumors in the first 5 min post-injection of RWY-dL-(Gd-DOTA)4 at a low dose of 0.03 mmol Gd/kg. Moreover, RWY-dL-(Gd-DOTA)4 generated superior contrast enhancement for liver tumors in chemical-induced HCC mice. Importantly, RWY-dL-(Gd-DOTA)4 provided complementary enhancement MR signals to the clinical available hepatobiliary MR contrast agent gadoxetate disodium Gd-EOB-DTPA. Additionally, RWY-dL-(Gd-DOTA)4 showed minimal gadolinium retention in normal tissues and organs at 48 h post-injection. CONCLUSION: These findings potentiate the use of RWY-dL-(Gd-DOTA)4 for the MRI of HCC to improve the diagnosis of HCC.

Submucosal Saline Injection Followed by Endoscopic Ultrasound versus Endoscopic Ultrasound Only for Distinguishing between T1a and T1b Esophageal Cancer.

PURPOSE: To examine whether submucosal saline injection (SSI) can improve traditional endoscopic ultrasound (EUS) accuracy in distinguishing between T1a and T1b stage esophageal squamous cell carcinoma (ESCC). EXPERIMENTAL DESIGN: Patients with T1N0M0 stage ESCC (n = 180) ages 18 to 85 years were enrolled between February 14, 2012 to June 4, 2018 at Sun Yat-sen University Cancer Center (Guangdong, China). They were randomly assigned (1:1) to receive either EUS examination after 3-5 mL SSI or EUS only examination. All the patients were referred to thoracic surgeons to receive endoscopic resection (ER) or esophagectomy 5 to 10 days after EUS examination. Standard EUS criteria were used to preoperatively stage the ESCC cases, and surgical pathology reports after referral were used to postoperatively stage the cases. The primary endpoint was the diagnostic accuracy of T1b staging [defined as the sum of the true positive (T1b) and true negative (T1a) cases divided by the total number of cases]. RESULTS: Among the per-protocol population, the SSI+EUS group (n = 81) was superior to the EUS-only group (n = 85) in terms of the diagnostic accuracy for T1b staging [93.8% (95% confidence interval (CI), 88.6-99.1) vs. 65.9% (95% CI, 55.8-76.0); P < 0.001]. The positive predictive value of SSI+EUS for diagnosing T1b ESCC reached 90.9% (95% CI, 81.1-100), which was significantly superior to that of EUS only [0.576 (0.450-0.702), P = 0.001]. CONCLUSIONS: SSI significantly improves the diagnostic accuracy of EUS in distinguishing between T1a and T1b ESCC, which might help avoid unnecessary esophagectomy and diagnostic ER.

Integrin α6-Targeted Positron Emission Tomography Imaging of Colorectal Cancer.

Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer deaths worldwide. Integrin α6 is overexpressed in all stages of CRC which makes it a potential diagnostic biomarker for CRC. Previously, we identified an integrin α6-targeted peptide CRWYDENAC (dubbed RWY) using phage display technology and employed it for nasopharyngeal carcinoma specific nanotherapeutics. In this study, we developed a radiotracer, 18F-RWY, based on this integrin α6-targeted RWY peptide for positron emission tomography (PET) imaging of CRC. Integrin α6 was overexpressed on several CRC cells including HT29 cells where the biotin-labeled RWY peptide colocalized with integrin α6. 18F-RWY PET imaging was performed on subcutaneous, chemically induced, and genetically engineered CRC mice. 18F-RWY generated high PET signals in subcutaneous HT29 tumors, and the tumor uptake of 18F-RWY was reduced by a blocking study using nonradio-labeled RWY. Moreover, 18F-RWY PET imaging enabled detection of CRC in chemically induced and genetically engineered CRC mice. The overexpression of integrin α6 in tumor tissues isolated from chemically induced and genetically engineered CRC mice was confirmed. These results demonstrate the potential clinical application of 18F-RWY for PET imaging of CRC.

Integrin α6 targeted positron emission tomography imaging of hepatocellular carcinoma in mouse models.

Integrin α6 emerges to be a diagnostic biomarker for hepatocellular carcinoma (HCC). Here, we translated our previously identified integrin α6 targeted peptide RWY into a positron emission tomography (PET) tracer 18F-RWY for the detection of HCC lesions in following four HCC mouse models including subcutaneous, orthotopic, genetically engineered and chemical induced HCC mice. 18F-RWY produced high PET signals in liver tumor tissues that were reduced by blocking studies using nonradiolabeled RWY peptide. We compared the integrin α6 targeted PET tracer 18F-RWY with the integrin αvß3-targeted PET tracer 18F-3PRGD2 and the clinical PET tracer 18F-FDG in chemical induced HCC mice. Among 12 HCC identified by enhanced magnetic resonance imaging (MRI) with hepatocellular specific gadoxetate disodium Gd-EOB-DTPA, the sensitivities of 18F-RWY, 18F-3PRGD2 and 18F-FDG were approximately 92%, 73% and 50% while the tumor-to-liver ratios were 4.36 ±â€¯1.41, 1.97 ±â€¯0.43 and 1.63 ±â€¯0.23 respectively. Additionally, PET imaging with the integrin α6 targeted 18F-RWY enabled to visualize small HCC lesions with diameters approximately 0.2 cm that was hard to be distinguished from surround hepatic vascular by enhanced MRI with Gd-EOB-DTPA. These findings potentiate the use of integrin α6 targeted PET tracer 18F-RWY for the detection of HCC.

Identification of a sodium pump Na+/K+ ATPase α1-targeted peptide for PET imaging of breast cancer.

The sodium pump Na+/K+ ATPase a1 subunit(NKA a1), an attractive cancer-related biomarker and therapeutic target, is closely related to the development and progression of several cancers including breast cancer. Currently, a NKA a1 inhibitor, UNBS1450, has already evidenced its great therapeutic potential in personalized cancer treatment. The ability of non-invasive imaging of NKA a1 expression would be useful for selecting cancer patients who may benefit from this drug. Here, we identified an S3 peptide that is specifically homed to breast cancer by phage display. All data of in vitro and in vivo experiments suggested the excellent targeting character of the S3 peptide. As the binding activity of the S3 phage was positively correlated to the level of NKA α1 expression in various breast cancer cells, NKA α1 was validated as the primary target of the S3 peptide. Based on immunohistochemistry staining result of 107 breast cancer patients, NKA α1 was verified to be a novel tracking marker and a prognostic predictor for breast cancer. Importantly, we proposed and validated an S3 peptide-based radiotracer 18F-ALF-NOTA-S3 for PET (Positron Emission Tomography) imaging of breast cancer and other NKA α1-overexpressing cancers, including hepatocellular carcinoma and non-small cell lung cancer, in mouse models. Our findings demonstrated the potential application of 18F-ALF-NOTA-S3 for visualization of NKA α1-positive lesions, which provide a new approach to character tumor phenotypic imaging.