Objective:To prepare a 177Lu labeled human epidermal growth factor receptor 2 (HER2) affibody 177Lu-1, 4, 7-triazacyclononane-1, 4, 7-triacetic acid (NOTA)-maleimide (Mal)-cysteine (Cys)-ZHER 2: 342 ( 177Lu-NOTA-MZHER2 for short), and investigate its labeling process and anti-tumor properties. Methods:Two kinds of buffer systems (sodium acetate buffer system and sodium ascorbate buffer system) were investigated. The effects of pH value, precursor mass and reaction temperature on 177Lu labeling NOTA-MZHER2 were compared to obtain optimal labeling conditions. The radiochemical purity of labeled product was determined by instant thin-layer chromatography (ITLC), and its stabilities in PBS and plasma were observed. Human ovarian cancer cell line SKOV-3 was selected for cell internalization and cytotoxicity test to evaluate cell uptake and killing effect of 177Lu-NOTA-MZHER2. SKOV-3 tumor-bearing mice( n=3) were injected with 177Lu-NOTA-MZHER2, and microSPECT/CT imaging was performed. Another 40 tumor-bearing mice were divided into 22.2 MBq group (tail vein injection with probe of 22.2 MBq), control group (tail vein injection with PBS), low-dose group (tumor injection with probe of 3.7 MBq) and high-dose group (tumor injection with probe of 7.4 MBq). Tumor volume and mass of tumor-bearing mice were monitored after injection, and the anti-tumor effect and toxicity of probe were evaluated. Repeated measurement analysis of variance (Bonferroni method) was used to analyze the data. Results:The optimal labeling condition was 70-80 ℃ for 30 min in the system of sodium acetate buffer solution with pH=4 and precursor mass of 50 μg. Under these conditions, the labeling rate of 177Lu-NOTA-MZHER2 was (99.3±0.4)% and radiochemical purity was >99%. After 12 d in PBS and plasma, the radiochemical purities were (95.0±1.5)% and (95.0±2.1)%. Results of cell experiment showed that the internalization of 177Lu-NOTA-MZHER2 accounted for (29.02±3.50)% of the total uptake, and the survival rate of SKOV-3 cells was (48±6)% with the probe concerntration of 6×10 -3 Bq/L. SPECT imaging showed that 177Lu-NOTA-MZHER2 was still concentrated at the tumor site 96 h after injection with a dose of 18.5 MBq. Relative tumor volume (RTV) of tumor-bearing mice in 22.2 MBq group, high-dose group and low-dose group was significantly different from that in control group ( F=21.75, P<0.001). Twenty days after injection, RTV and relative body mass of the tumor-bearing mice in high-dose group were (140±7)% and (80±9)%, respectively. Compared with control group, high-dose group had obvious anti-tumor effect (both P<0.001). Conclusion:177Lu-NOTA-MZHER2 is successfully prepared, which is simple and efficient, and the probe has good anti-tumor effect.

Objective:To radiolabel hyperbranched polymer (HG)-modified liquid metal nanodroplet (LMND)@HG with 177Lu, and explore the radiotherapy sensitization effect on anti-breast cancer therapy. Methods:The ultrasonication method was used to prepare LMND@HG, and then 177LuCl 3 was mixed with LMND@HG to label 177Lu by alloying reactions. The labeling rate, plasma stability and cytotoxicity of 177Lu-LMND@HG were detected. Xenograft mouse model of breast cancer was constructed, and the tumor inhibition test was performed by an intratumoral injection. The tumor progression was monitored by in vivo imaging system. The mechanism of tumor inhibition was verified by immunohistochemistry and immunofluorescence assays. One-way analysis of variance, repeated measures analysis of variance, and the least significant difference t test were used to analyze the data. Results:177Lu was successfully labeled to LMND@HG with a high labeling efficiency >95%. The product did not require further purification and the plasma radiochemical purity was still higher than 95% after 5 d. The cytotoxicity test showed that a dose of 888 kBq (40 mg/L) 177Lu-LMND@HG had obvious toxicity to 4T1 cells, which was significantly lower than 177LuCl 3 (cell viabilities: (16.48±7.81)% vs (85.77±8.87)%; F=77.81, t=11.73, P<0.001) and LMND@HG ((46.53±5.75)%; t=6.20, P<0.001). The biological distribution results showed that 177Lu-LMND@HG was mainly distributed in tumor tissue 5 d after intratumoral injection. The results of the tumor inhibition experiment showed that 1.48 MBq 177Lu-LMND@HG could significantly inhibit the tumor growth compared with the 177LuCl 3 (tumor volume: (222.66±97.70) vs (789.13±245.04) mm 3;F=18.55, t=4.29, P=0.005). In vivo optical imaging of small animals showed that 1.48 MBq and 3.70 MBq 177Lu-LMND@HG both significantly inhibited the tumor growth. Immunofluorescence and immunohistochemical results showed that 177Lu-LMND@HG caused double-stranded DNA break, and suppressed the tumor growth by inhibiting cell proliferation and angiogenesis. Conclusions:A novel 177Lu-liquid metal-based reactive oxygen species (ROS) radiation sensitizer is successfully prepared in this study. The preparation method is efficient and convenient, and the product has high stability. 177Lu-LMND@HG shows an obvious radiotherapy sensitization effect on breast tumor-bearing mice.

Objective:To prepare a novel 68Ga-labeled bicyclic peptide targeting poliovirus receptor related protein 4 (PVRL4, Nectin-4), and evaluate its feasibility for breast cancer imaging via in vitro and in vivo experiments. Methods:A Biotin-modified bicyclic peptide targeting Nectin-4, Biotin-BMIC, was synthesized, and its targeting properties were preliminarily evaluated by in vitro cell staining experiments. BMIC was modified by 1, 4, 7-triazonane-1, 4-diacetic acid (NODA) and the labeling precursor NODA-BMIC was prepared. A potential PET probe targeting Nectin-4, 68Ga-NODA-BMIC was prepared by one-step labeling strategy. The imaging properties of the probe were investigated by in vivo microPET imaging and in vitro experiments in mice bearing breast tumors. Data were analyzed by independent-sample t test and repeated measures analysis of variance. Results:Fluorescence staining of the cells showed that the fluorescently labeled bicyclic peptide, Biotin-BMIC, was highly aggregated in Nectin-4 positive BT474 breast cancer cells compared to those in Nectin-4 negative MDA-MB-231 cells. The uncorrected yield of 68Ga-NODA-BMIC was (71.5±2.2)% and the radiochemical purity was greater than 95%. The specific activity was greater than 3 GBq/μmol. After incubation 10, 30, 60 and 120 min, higher radioactivity uptakes were found in BT474 breast cancer cells compared to those in MDA-MB-231 breast cancer cells respectively ( F=1 302.00, P<0.001). MicroPET imaging showed that the BT474 xenograft tumors were clearly visible with favorable contrast. A significant statistical difference in uptakes between BT474 and MDA-MB-231 xenograft tumor uptake at 10, 30, 60, and 120 min after probe injection respectively was existed ( F=1 826.00, P<0.001). At 60 min postinjection, the uptake value of BT474 tumors was (5.03±0.14) percentage activity of injection dose per gram of tissue (%ID/g), which was significantly higher than that of MDA-MB-231 tumors ((0.19±0.04) %ID/g; t=79.40, P<0.001). Meanwhile, the tumor-to-muscle ratios in the former were also greater than those in the latter ( F=222.00, P<0.001). At 60 min postinjection, the tumor-to-muscle ratio in the former was significantly higher than that in the latter (24.75±3.10 vs 1.30±0.15; t=14.31, P=0.002). The results were consistent with the immunohistochemistry staining. Conclusions:A novel bicyclic peptide PET probe targeting Nectin-4, 68Ga-NODA-BMIC, is easy to be synthesized and owns satisfactory labeling yield and radiological purity. The imaging performance is good and the target tissues could be visualized. It may play a unique role in the diagnosis and treatment of breast cancer.

Objective:To investigate the dosimetric effects of prone immobilization devices combined with a belly board (PIDBBs) in the intensity-modulated radiotherapy (IMRT) for gynecologic cancers.Methods:A total of 20 patients with cervical or endometrial cancer treated with radiotherapy in the Third Affiliated Hospital of Sun Yat-sen University from August 2020 to June 2021 were retrospectively analyzed. Two sets of body contours were outlined for each patient. One set of body contours did not contain the immobilization devices, and the other contour set included the immobilization devices. For each patient, doses were calculated for the two sets of contours using the same 7-field IMRT plan and were recorded as Plan without and Plan with. The dosimetric difference caused by the immobilization devices was assessed by comparing the parameter values in the dose-volume histograms (DVHs) and by plan subtraction. The Gafchromic EBT3 film and anthropomorphic phantom were used to verify the calculated doses. Results:The target coverage and average dose of Plan with were lower than those of Plan without. Specifically, the V50 Gy, V49 Gy, and Dmean of planning target volume (PTV) decreased by 19.75%, 7.99%, and 2.54% ( t = 8.96, 10.49, 22.09, P < 0.01), respectively. The V40 Gy, V30 Gy, V20 Gy, V15 Gy, and Dmean of skins increased by 51.79%, 51.05%, 45.72%, 33.63% and 10.80% ( t = -2.54, -5.63, -15.57, -24.06, -13.88, P < 0.01), respectively. Doses to other organs at risk (OARs) showed no significant differences. As indicated by the EBT3 measurements, the doses to skins of the abdomen and pelvis on the anthropomorphic phantom increased by approximately 37.24% ( t = 10.86, P<0.01). Conclusions:Although PIDBBs can effectively reduce the low dose to the small intestine, the radiation attenuation caused by them can reduce the PTV coverage of radiotherapy plans and increase the doses to abdominal and pelvic skins sharply, especially for patients requiring irradiation of the groin and perineum.

Objective:To label mesenchymal stem cells (MSCs) with 89Zr-oxine complex, and assess its characteristics of PET imaging in systemic lupus erythematosus (SLE) model (MRL/lpr mice). Methods:SLE mice were screened by 18F-FDG PET imaging. 89Zr-oxine was prepared and used for labeling MSCs (10 6 MSCs and 1 MBq 89Zr-oxine). 89Zr-oxine-labeled MSCs (0.2 MBq) were injected into MRL/lpr mice and BALB/c mice (each n=5) via tail vein at a dose of 1.2×10 6 cells per mouse, and followed with microPET imaging in vivo at 2 h, 6 h, 1 d, 3 d, 7 d, 10 d and 14 d after injection. The percentage activity of injection dose per gram of tissue (%ID/g) was calculated. Independent-sample t test was used to analyze the data. Results:MSCs was successfully labeled with 89Zr-oxine, with the labeling efficiency of 20% and cell viability >90%. MicroPET imaging showed that MSCs were mainly distributed in lungs and the liver sites at 2 h after injection. The number of MSCs homing to kidneys of MRL/lpr mice ( n=5) increased significantly 24 h after the injection, and the renal uptake of MSCs in MRL/lpr mice was much higher than that in BALB/c mice ((8.28±1.27) vs (4.33±0.94) %ID/g; t=3.54, P=0.024). The renal uptake increased firstly and then decreased and then leveled off, indicating MSCs homing to kidneys. Conclusions:A method for 89Zr-oxine labeling of MSCs is successfully established. 89Zr-labeled MSCs can home to kidneys of SLE mice. PET imaging of 89Zr-labeled MSCs can be effectively used to explore the in vivo distribution and migration behavior of transplanted MSCs during the treatment of diseases such as SLE.

Non-coding RNAs(ncRNAs) are special RNAs that they don't have protein coding function, but they can affect chromosome structure, gene transcription and participate in the processes of epigenetic modifications. ncRNAs include long non-coding RNAs, microRNA, etc. In recent years, it has been found that these ncRNAs can maintain bone remodeling by adjusting bone resorption and formation in osteoporosis(OP). In the future, it may be a key target of the drug action screening which is clarifying the regulatory mechanism of ncRNAs in the occurrence and development of OP. OP belongs to bone rheumatism category in traditional Chinese medicine, according to the theory of “the kidney generating marrow and dominating bone” in traditional Chinese medicine, kidney tonifying and bone strengthening formulas are used to treat the OP in clinic, and the curative effect is remarkable. It has been found that kidney tonifying and bone strengthening prescriptions can enhance the proliferation of osteoblasts or inhibit the differentiation of osteoclasts by up-regulating or down-regulating the expression of ncRNA, and finally maintain OP bone homeostasis, thus exerting therapeutic effect. However, the specific molecular mechanism is still in its exploratory stage. Therefore, this paper summarized the molecular mechanism of kidney tonifying and bone strengthening prescriptions regulating ncRNAs in the treatment of OP in recent years, in order to provide the new ideas for the screening of the key therapeutic targets of OP drugs and the prevention and treatment of OP with traditional Chinese medicine.

Objective:To synthesize N- 18F-fluoroethyl-tofacitinib, and explore its feasibility in the diagnosis of rheumatoid arthritis (RA). Methods:The " two-step method" was used to modify tofacitinib with 18F-fluoroethyl, and the labeling rate and radiochemical purity of the probe were measured by high performance liquid chromatography (HPLC), and the stabilities of the probe in vivo and in vitro were investigated. BALB/c mice (normal group; n=3) and collagen-induced arthritis (CIA) model mice (CIA group; n=3) were injected with N- 18F-fluoroethyl-tofacitinib and CIA model mice injected with tofacitirrib and N- 18F-fluoroethyl-tofacitinib were as blocking group ( n=3). All mice underwent microPET imaging and the percentage injection dose per gram of tissue (%ID/g) and the uptake ratio of inflamed joints to muscle (T/M) were calculated. One-way analysis of variance and the least significant difference (LSD) t test were used to analyze the data. Results:The synthesis time of N- 18F-fluoroethyl-tofacitinib was about 120 min, with the yield approximately 1%, the specific activity >13.6 GBq/μmol, and the radiochemical purity >99%. After the probe incubated with PBS, plasma or in vivo for 2 h, the radiochemical purity was still more than 95%. MicroPET imaging showed that 30 min after injection, the uptake of N- 18F-fluoroethyl-tofacitinib in the inflamed joints of CIA group was higher than that of normal group and blocking group ((10.22±1.64), (2.71±0.26) and (2.81±0.33) %ID/g; F=58.26, t values: 7.83, 7.67, P values: 0.001, 0.002). The T/M of CIA group was also higher than that of normal group and blocking group (24.73±5.77, 2.75±1.36 and 2.89±0.54; F=40.64, t values: 6.42, 6.53, P values: 0.003, 0.003). Conclusions:N- 18F-fluoroethyl-tofacitinib is successfully prepared and it is stable in vitro with good imaging performance in vivo. It may be used in clinic for the diagnosis of RA.

Colorectal cancer (CRC) is the most lethal gastrointestinal cancer in both males and females worldwide (Sung et al., 2021). Because of the high heterogeneity of tumors, robust prognostic biomarkers are urgently needed in CRC management (Koncina et al., 2020). Chemokine signaling is a well-known pivotal player in immunity, inflammation, and cancer metastasis (Lacalle et al., 2017; Poeta et al., 2019; Do et al., 2020), and multiple genes involved in chemokine signaling have been demonstrated as potential prognostic biomarkers for CRC (Cabrero-De Las Heras and Martínez-Balibrea, 2018; Ottaiano et al., 2020; Yu et al., 2020). Therefore, the aim of our study was to develop a chemokine signaling-based multigene signature (CSbMgSig) that could effectively predict overall survival (OS) and therapeutic response for patients with CRC.

Objective:To study the protective effects of different concentrations of curcumin on lung injury of rats in dry heat environment.Methods:Fifty Sprague-Dawley rats were randomly (random number) divided into five groups ( n = 10 each group): normal control group (NC), dry heat control group (DHC), and three different concentrations of curcumin pretreated dry-heat groups (50 mg/kg, 100 mg/kg, and 200 mg/kg). Rats in the NC and DHC groups were given a gavage of normal saline, and rats in the curcumin pretreatment groups were given a gavage of curcumin with different concentrations, once a day for 7 consecutive days. At 8th day, all groups except for the NC group were transferred to the climate cabin (The Simulated Climate Cabin for Special Environment of Northwest of China), with a temperature of (41 ± 0.5) and relative humidity of (10 ± 1)%. Rats in each group were anesthetized and sampled after reaching the state of heat stroke at 150 min, and same done to the NC group. Lung tissues were harvested and pathological changes were observed by HE staining. Lung wet/dry (W/D) weight ratio was detected and lung injury indicators such as total protein, white blood cell count and neutrophil count in bronchoalveolar lavage fluid (BALF) were also determined. Results:The lung injury pathology score, W/D weight ratio, total protein, white blood cell count and neutrophil count in BALF were the lowest in the NC group, and the highest in the DHC group, with significant difference ( P <0.01). With the increase of the concentration in the curcumin pretreatment groups, lung injury pathology score, W/D weight ratio, total protein, white blood cell count and neutrophil count in BALF were all declined. There were significant differences among the different concentration groups of curcumin and the NC and DHC groups ( P <0.01). Correlation analysis indicated that lung injury scores were correlated with W/D weight ratio of lung tissue, alveolar total protein content in BALF, white blood cell count, and neutrophil count (correlation coefficient r = 0.879, r = 0.935, r = 0.916, and r = 0.880, respectively, P <0.01). Conclusions:Pretreatment with different concentrations of curcumin can exert protective effects on lung injury of heat stroke rats in dry heat environment. Curcumin may have important clinical value in prevention and treatment of lung injury caused by heat stroke in dry heat environment.

Objective:To prepare a 68Ga labeled human epidermal growth factor receptor 2 (HER2) affibody 68Ga-1, 4, 7-triazacylononane-1, 4, 7-triacetic acid (NOTA)-maleimide (MAL)-Cysteine (Cys)-Glycine-Glycine-Glycine-Arginine-Aspartic acid-asparagine-HER 2: 342 affibody (GGGRDN-ZHER 2: 342)( 68Ga-MZHER), and evaluate its biodistribution and microPET characteristics. Methods:NOTA-MAL-Cys-GGGRDN-ZHER 2: 342 conjugate was labeled with 68Ga in one step. Radiochemical purity, radiolabeling yield and stability in vitro were analyzed. Normal mice ( n=24) were scarified at 15, 30, 60 and 120 min postinjection (1.85 MBq 68Ga-MZHER) to measure radioactive counts (percentage activity of injection dose per gram of tissue (%ID/g)) in main organs. Biodistribution and kinetics were evaluated by dynamic microPET in mice. Ovarian cancer (SKOV-3) models were established and microPET was performed at 30, 60 and 120 min postinjection of radiotracer. After administration of unlabeled Cys-ZHER 2: 342 peptide (10 mg/kg body weight) for 30 min, 68Ga-MZHER was injected into mice and PET images were acquired at 60 min postinjection. Region of interest (ROI) was drawn to access time-activity curve (TAC) in main organs and tumor. Six normal mice were used for the safety study. Results:68Ga-MZHER was synthesized in about 15 min with the yields more than 90%, and radiochemical purity more than 95%. The radiochemical purity was also determined to be more than 95% after being stored for 120 min at room temperature. Predominant uptake of 68Ga-MZHER was in the kidneys, and was cleared rapidly in normal tissues except the kidney. At 15 min postinjection, the renal uptake value was (106.36±15.74) %ID/g, then gradually increased with time, up to (145.15±28.04) %ID/g (60 min), and decreased to (86.12±22.75) %ID/g after 120 min postinjection. The blood pharmacokinetic of the probe in mice was fit with the two-compartment model. MicroPET imaging in mice bearing HER2 positive SKOV-3 tumors showed that the xenografts were clearly visualized with good contrast to normal tissue. The uptakes in tumors was determined to be (11.26±0.50), (12.27±1.13) and (12.65±0.89) %ID/g at 30, 60 and 120 min postinjection. Block experiment showed that the corresponding values decreased to (1.25±0.28) %ID/g at 60 min postinjection. Safety studies showed that after injection of 68Ga-MZHER for 30 d, the mice survived and no obvious abnormalities were observed in the main organs as shown in pathological results. Conclusions:68Ga-MZHER can be successfully labeled by one-step method. The 68Ga-MZHER probe owns the advantages of favorable imaging properties, convenient preparation, excellent stability, safety, rapid clearance in the blood, which support its application for further research.