AL355338 acts as an oncogenic lncRNA by interacting with protein ENO1 to regulate EGFR/AKT pathway in NSCLC.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a malignancy with considerable morbidity and mortality. Abnormal metabolism is a hallmark of cancer; however, the mechanism of glycolysis regulation in NSCLC progression is not completely understood. Recent studies suggest that some dysregulated long non-coding RNAs (lncRNAs) play important roles in tumor metabolic reprogramming. METHODS: To identify glycolysis-associated-lncRNAs in NSCLC, we compared RNA-sequencing results between high 18F-fluorodeoxyglucose (FDG)-uptake NSCLC tissues and paired paratumor tissues. The transcript abundance of AL355338 in 80 pairs of clinical samples was evaluated by quantitative real-time PCR assay and fluorescence in situ hybridization. The biological role of AL355338 on NSCLC cells were evaluated by functional experiments in vitro and in vivo. Moreover, RNA pull-down, mass spectrometry and RNA immunoprecipitation (RIP) assays were used to identify the protein interacted with AL355338. Co-immunoprecipitation, in situ proximity ligation assays and western blotting were applied to define the potential downstream pathways of AL355338. RESULTS: AL355338 was an upregulated glycolysis-associated lncRNA in NSCLC. Functional assays revealed that AL355338 was critical for promoting aerobic glycolysis and NSCLC progression. Mechanistic investigations showed that AL355338 directly bound with alpha-enolase (ENO1) and enhanced the protein's stability by modulating its degradation and ubiquitination. A positive correlation was observed between AL355338 and ENO1 in NSCLC, and ENO1 was subsequently confirmed to be responsible for the oncogenic role of AL355338. Furthermore, AL355338 was capable of modulating ENO1/EGFR complex interaction and further activating EGFR-AKT signaling. CONCLUSIONS: This study indicates that AL355338 confers an aggressive phenotype to NSCLC, and targeting it might be an effective therapeutic strategy.

Non-invasive glucagon-like peptide-1 receptor imaging in pancreas with (18)F-Al labeled Cys(39)-exendin-4.

PURPOSE: Glucagon-like peptide-1 receptor (GLP-1R) is abundantly expressed on beta cells and may be an ideal target for the pancreas imaging. Monitoring the GLP-1R of pancreas could be benefit for understanding the pathophysiology of diabetes. In the present study, (18)F-Al labeled exendin-4 analog, (18)F-Al-NOTA-MAL-Cys(39)-exendin-4, was evaluated for PET imaging GLP-1R in the pancreas. METHODS: The targeting of (18)F-Al labeled exendin-4 analog was examined in healthy and streptozotocin induced diabetic rats. Rats were injected with (18)F-Al-NOTA-MAL-Cys(39)-exendin-4 and microPET imaging was performed at 1 h postinjection, followed by ex vivo biodistribution. GLP-1R expression in pancreas was determined through post mortern examinations. RESULTS: The pancreas of healthy rats was readily visualized after administration of (18)F-Al-NOTA-MAL-Cys(39)-exendin-4, whereas the pancreas of diabetic rats, as well as those from rats co-injected with excess of unlabeled peptides, was barely visible by microPET. At 60 min postinjection, the pancreatic uptakes were 1.02 ± 0.15%ID/g and 0.23 ± 0.05%ID/g in healthy and diabetic rats respectively. Under block, the pancreatic uptakes of non-diabetic rats reduced to 0.21 ± 0.07%ID/g at the same time point. Biodistribution data and IHC staining confirmed the findings of the microPET imaging. CONCLUSION: The favorable preclinical data indicated that (18)F-Al-NOTA-MAL-Cys(39)-exendin-4may be suitable for non-invasive monitoring functional pancreatic beta cells.

(18)F-Alfatide II PET/CT in healthy human volunteers and patients with brain metastases.

PURPOSE: We report the biodistribution and radiation dosimetry of an integrin αvß3 specific PET tracer (18)F-AlF-NOTA-E[PEG4-c(RGDfk)]2) (denoted as (18)F-Alfatide II). We also assessed the value of (18)F-Alfatide II in patients with brain metastases. METHODS: A series of torso (from the skull to the thigh) static images were acquired in five healthy volunteers (3 M, 2 F) at 5, 10, 15, 30, 45, and 60 min after injection of (18)F-Alfatide II (257 ± 48 MBq). Regions of interest (ROIs) were drawn manually, and the time-activity curves (TACs) were obtained for major organs. Nine patients with brain metastases were examined by static PET imaging with (18)F-FDG (5.55 MBq/kg) and (18)F-Alfatide II. RESULTS: Injection of (18)F-Alfatide II was well tolerated in all healthy volunteers, with no serious tracer-related adverse events found. (18)F-Alfatide II showed rapid clearance from the blood pool and kidneys. The total effective dose equivalent (EDE) and effective dose (ED) were 0.0277 ± 0.003 mSv/MBq and 0.0198 ± 0.002 mSv/MBq, respectively. The organs with the highest absorbed dose were the kidneys and the spleen. Nine patients with 20 brain metastatic lesions identified by MRI and/or CT were enrolled in this study. All 20 brain lesions were visualized by (18)F-Alfatide II PET, while only ten lesions were visualized by (18)F-FDG, and 13 by CT. CONCLUSION: F-Alfatide II is a safe PET tracer with a favorable dosimetry profile. The observed ED suggests that (18)F-Alfatide II is feasible for human studies. (18)F-Alfatide II has potential value in finding brain metastases of different cancers as a biomarker of angiogenesis.

Hypoxia-induced lncRNA-AC020978 promotes proliferation and glycolytic metabolism of non-small cell lung cancer by regulating PKM2/HIF-1α axis.

Rationale: Non-small cell lung cancer (NSCLC) is a deadly disease with a hallmark of aberrant metabolism. The mechanism of glycolysis associated lncRNA underlying the aggressive behaviors of NSCLC is poorly understood. Methods: The expression level of AC020978 in NSCLC was measured by quantitative real-time PCR and fluorescence in situ hybridization (FISH) assay. The biological role of AC020978 in cell proliferation and aerobic glycolysis was determined by functional experiments in vitro and in vivo. The transcription of AC020978 was assessed by dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assay. RNA pull-down, mass spectrometry and RNA immunoprecipitation (RIP) assays were used to identify the interaction protein with AC020978. Western blotting, in situ proximity ligation assay (PLA), and co-immunoprecipitation (co-IP) were performed to reveal the potential mechanism of AC020978. Results: The present study indicated that AC020978 was upregulated in NSCLC, significantly correlated with advanced TNM stage and poor clinical outcomes, representing as an independent prognostic predictor. Functional assays revealed AC020978's role in promoting cell growth and metabolic reprogramming. Moreover, AC020978 was an upregulated lncRNA under glucose starvation as well as hypoxia conditions, and directly transactivated by HIF-1α. Mechanistic investigations identified that AC020978 directly interacted with Pyruvate kinase isozymes M2 (PKM2) and enhanced PKM2 protein stability. Besides, this study uncovered that AC020978 could promote the nuclear translocation of PKM2 and regulate PKM2-enhanced HIF-1α transcription activity. Conclusions: Together, these data provided evidence that AC020978 conferred an aggressive phenotype to NSCLC and was a poor prognosticator. Targeting AC020978 might be an effective therapeutic strategy for NSCLC.

LINC01123, a c-Myc-activated long non-coding RNA, promotes proliferation and aerobic glycolysis of non-small cell lung cancer through miR-199a-5p/c-Myc axis.

BACKGROUND: Long non-coding RNAs (lncRNAs) have been associated with non-small cell lung cancer (NSCLC), but the underlying molecular mechanisms of their specific roles in mediating aerobic glycolysis have been poorly explored. METHODS: Next-generation RNA sequencing assay was performed to identify the differentially expressed RNAs between NSCLC tissues with high 18F-fluorodeoxyglucose (FDG) uptake and their adjacent normal lung tissues. LINC01123 expression in NSCLC tissues was measured by real-time PCR and in situ hybridization (ISH) assay. The biological role of LINC01123 in cell growth and aerobic glycolysis capability was determined by performing functional experiments in vitro and in vivo. Further, the transcription of LINC01123 was explored by bioinformatics analysis, dual-luciferase reporter assay, and chromatin immunoprecipitation (ChIP) assay. RNA immunoprecipitation (RIP) and luciferase analyses were used to confirm the predicted competitive endogenous RNA (ceRNA) mechanisms between LINC01123 and c-Myc. RESULTS: Three hundred sixty-four differentially expressed genes were identified in RNA-seq assay, and LINC01123 was one of the most overexpressed lncRNAs. Further validation in expanded NSCLC cohorts confirmed that LINC01123 was upregulated in 92 paired NSCLC tissues and associated with poor survival. Functional assays showed that LINC01123 promoted NSCLC cell proliferation and aerobic glycolysis. Mechanistic investigations revealed that LINC01123 was a direct transcriptional target of c-Myc. Meanwhile, LINC01123 increased c-Myc mRNA expression by sponging miR-199a-5p. In addition, rescue experiments showed that LINC01123 functioned as an oncogene depending on miR-199a-5p and c-Myc. CONCLUSION: Since LINC01123 is upregulated in NSCLC, correlates with prognosis, and controls proliferation and aerobic glycolysis by a positive feedback loop with c-Myc, it is expected to be a potential biomarker and therapeutic target for NSCLC.

PET imaging of a 68Ga labeled modified HER2 affibody in breast cancers: from xenografts to patients.

OBJECTIVE: Overexpression of human epidermal growth factor receptor-2 (HER2) in breast cancers provides promising opportunities for imaging and targeted therapy. Developing HER2 targeted positron emission tomography (PET) probes might be benefit for management of the disease. Small high-affinity scaffold proteins, affibodies, are ideal vectors for imaging HER2 overexpressed tumors. Despite of the initial success on development of 18F labeled ZHER2:342 affibody, the tedious synthesis producers, low yields and unfavorable pharmacokinetics may hinder the clinical use. 68Ga is an attractive positron emitter for PET imaging. A simple preparation of 68Ga labeled ZHER2:342 analog, 68Ga-NOTA-MAL-Cys-MZHER2:342, was reported in the study. The in vivo performances of the tracer for assessing HER2 status in breast cancers were also evaluated. METHODS: NOTA-MAL conjugated Cys-MZHER2:342 was radiolabeled with 68Ga. The probe was evaluated by in vitro tests including stability and cell binding studies in breast cancer cells with different HER2 levels. In vivo evaluation was performed in mice bearing tumors using microPET imaging and biodistribution experiments. A PET/CT imaging study was initially performed in patients with breast cancers. RESULTS: The tracer was synthesized in a straightforward chelation method with satisfactory non-decay corrected yield (81±5%) and radiochemical purity (>95%). In vivo micro-PET imaging showed that HER2 high levels expressed BT474 xenografts were more clear visualized than HER2 low levels expressed MCF-7 tumors (16.12 ± 2.69 ID%/g vs 1.32 ± 0.19 ID%/g at 1 h post-injection). The outcome was consistent with the immunohistochemical analysis. No significant radioactivity was accumulated in healthy tissues (less than 2% ID/g) except kidneys. In a preliminary clinical study, 68Ga-NOTA-MAL-Cys-MZHER2:342 PET imaging allowed more high-contrast detection of HER2 positive primary tumors (maximum standardized uptake value = 2.16±0.27) than those in HER2 negative primary focus (maximum standardized uptake value = 0.32±0.05). No detectable side-effects were found. CONCLUSION: In summary, this study indicates the significant efficiency of the 68Ga labeled HER2 affibody. Preclinical and clinical studies support the possibility of monitoring HER2 levels in breast cancers using 68Ga-NOTA-MAL-Cys-MZHER2:342. ADVANCES IN KNOWLEDGE: The research investigated the feasibility of a 68Ga labeled HER2 affibody modified with a hydrophilic linker for breast cancer PET imaging. Favorable outcomes showed that the probe might be valuable for determining HER2 status of the disease.

The emerging co-regulatory role of long noncoding RNAs in epithelial-mesenchymal transition and the Warburg effect in aggressive tumors.

Malignant tumor cells have several unique characteristics, and their ability to undergo epithelial-mesenchymal transition (EMT) is a molecular gateway to invasive behavior. Rapid proliferation and increased invasiveness during EMT enhance aberrant glucose metabolism in tumor cells. Meanwhile, aerobic glycolysis provides energy, biosynthesis precursors, and an appropriate microenvironment to facilitate EMT. Reciprocal crosstalk between the processes synergistically contributes to malignant cancer behaviors, but the regulatory mechanisms underlying this interaction remain unclear. Long non-coding RNAs (lncRNAs) are a recently recognized class of RNAs involved in multiple physiological and pathological tumor activities. Increasing evidence indicates that lncRNAs play overlapping roles in both EMT and cancer metabolism. In this review, we describe the lncRNAs reportedly involved in the two biological processes and explore the detailed mechanisms that could help elucidate this co-regulatory network and provide a theoretical basis for clinical management of EMT-related malignant phenotypes.

Comparing the Differential Diagnostic Values of 18F-Alfatide II PET/CT between Tuberculosis and Lung Cancer Patients.

Purpose: To compare the differential diagnostic values of 18F-Alfatide II PET/CT between tuberculosis and lung cancer patients and in patients with sarcoidosis and common inflammation. Methods: Nine inflammation patients (4 tuberculosis, 3 sarcoidosis, and 2 common inflammation) and 11 lung cancer patients were included in this study. All patients underwent 18F-FDG and 18F-Alfatide II PET/CT within 2 weeks, followed by biopsy and surgery. The maximized standard uptake value (SUVmax) and the mean standard uptake value (SUVmean) were evaluated. Results: The active tuberculosis lesions showed a high accumulation of 18F-FDG, but varying degrees of accumulation of 18F-Alfatide II, including negative results. The SUVmax of 18F-Alfatide II in malignant lesions was significantly higher than that in tuberculosis (4.08 ± 1.51 versus 2.63 ± 1.34, P = 0.0078). Three patients with sarcoidosis showed negative results in 18F-Alfatide II PET/CT. Conclusions: The expression of αVß3 is much lower in tuberculosis as compared to that in lung cancer, and accumulation of 18F-Alfatide II varied even in lesions of the same patient. The negative results of sarcoidosis patients led to the speculation that αVß3 was not expressed in those lesions.

Pilot Prospective Evaluation of (18)F-Alfatide II for Detection of Skeletal Metastases.

This pilot prospective evaluation study is to verify the efficiency of (18)F-Alfatide II, a specific PET imaging agent for integrin αvß3, in detecting bone metastasis in human, with comparison to (18)F-FDG PET. Thirty recruited patients underwent (18)F-FDG and (18)F-alfatide II PET/CT successively within days. The final diagnosis of bone lesions was established based on the comprehensive assessment of all available data and clinical follow-up, which fall into four groups: osteolytic, osteoblastic, mixed and bone marrow. Visual analysis and quantification of SUVmax were performed to compare the detection sensitivity of (18)F-Alfatide II and (18)F-FDG PET. Eleven patients were found to have a total of 126 bone metastasis lesions. (18)F-Alfatide II PET can detect the bone metastatic lesions with good contrast and higher sensitivity (positive rate of 92%) than (18)F-FDG PET (77%). Especially, (18)F-Alfatide II PET showed superiority to (18)F-FDG PET in detecting osteoblastic (70% vs. 53%) and bone marrow metastatic lesions (98% vs. 77%). In conclusion, (18)F-Alfatide II PET/CT can be used to detect skeletal and bone marrow metastases, with nearly 100% sensitivity in osteolytic, mixed and bone marrow lesions. The sensitivity of (18)F-Alfatide II PET/CT in osteoblastic metastases is relatively low but still significantly higher than that of (18)F-FDG PET/CT. This pilot clinical study warrants the further application of (18)F-Alfatide II PET/CT in metastatic lesion detection, patient management and drug therapy response monitoring.

[The value of extra-lung lesions on ¹8F-FDG PET/CT in improving diagnosis of lung cancer].

BACKGROUND AND OBJECTIVE: ¹8F-FDG PET/CT has several shortcomings in discriminating between lung carcinoma and pulmonary benign lesions. The aims of the present study is to explore the value of extra-lung lesions on ¹8F-FDG PET/CT image in the diagnosis of lung cancer. METHODS: A total of 126 suspected lung cancer patients underwent ¹8F-FDG PET/CT scan. Preliminary diagnoses were based on the PET characteristics, SUVmean value, and CT characteristics of the lesions in the lung, and the diagnoses were modified based on the detected extra-lung lesions. The difference between the two methods and their disparity were calculated. RESULTS: Extra-lung lesions were identified on the PET/CT image in 81 patients; extra-lung metastasis modified 13 probable malignancies to affirmative malignancy and 1 probable malignancy to benign lesion. Non-metastasis modified 2 probable malignancies to affirmative malignancy and 1 probable malignancy to benign lesion. Fifteen were correct, whereas 2 were misdiagnosed. The diagnoses modification rate was 13.5% (17/126), and the modified diagnoses accuracy is 88.2% (15/17). CONCLUSIONS: Extra-lung lesions demonstrated on ¹8F-FDG PET/CT improved the diagnostic accuracy of lung cancer. Tuberculosis was identified as the most important reason for false positive diagnoses after modification by extra-lung lesions.