Clinicopathological features, treatment modalities, and prognosis of esophageal neuroendocrine carcinoma: A single-center retrospective study.

OBJECTIVES: Esophageal neuroendocrine carcinoma (ENEC) is a rare cancer that is highly malignant and related to a poor prognosis. In this retrospective study we aimed to elucidate the clinical characteristics, diagnosis and management of patients with ENEC and to evaluate the potential prognostic factors. METHODS: Altogether 82 patients diagnosed with ENEC between January 2009 and December 2020 at the Fudan University Shanghai Cancer Center were retrospectively enrolled. Patients' survival was analyzed using the Kaplan-Meier and log-rank methods. Univariate and multivariate analyses and a Cox regression model were used to identify the prognostic factors. RESULTS: The median overall survival (mOS) was 13 months in all patients. Multivariate analysis revealed that advanced tumor stage (hazard ratio [HR] 2.67, 95% confidence interval [CI] 1.07-6.66, P = 0.0353), liver (HR 3.36, 95% CI 1.53-7.41, P = 0.0026) and lung metastasis (HR 3.37, 95% CI 1.20-9.51, P = 0.0214) were associated with a poor prognosis. While positive chromogranin A (CgA) expression was related to a favorable outcome (HR 0.21, 95% CI 0.09-0.49, P < 0.001). Also, patients had adjustment of chemotherapy (dose reduction or less than three cycles) were prone to a worse prognosis compared with those did not (HR 4.36, 95% CI 2.10-9.08, P < 0.001). CONCLUSION: In patients with ENEC, advanced cancer stage, adjustment of chemotherapy, liver and lung metastasis were associated with a poor survival, while CgA expression was related to a favorable prognosis.

Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) Coordination Polymers Built from Dicarboxylic Acid/Tetracarboxylic Acid Ligands: Their Structural Diversity and Fluorescence Properties.

Six Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) coordination complexes are formulated as [Cd2(X2-)2(µ3-O)2/3]n (1), [Mn2(X2-)2(µ3-O)2/3]n (2), {[Co1.5(Y4-)0.5(4,4'-bpy)1.5(OH-)]·2H2O}n (3), {[Ni(X2-)(4,4'-bpy)(H2O)2]·4H2O}n (4), [Zn(m-bdc2-)(bebiyh)]n (5), and [Cd(5-tbia2-)(bebiyh)]n (6) (H2X = 3,3'-(2,3,5,6-tetramethyl-1,4-phenylene) dipropionic acid. H4Y = 2,2'-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene) dimalonic acid, bebiyh = 1,6-bis(2-ethyl-1H-benzo[d]imidazol-1-yl)hexane, m-H2bdc = 1,3-benzenedicarboxylic acid, and 5-H2tbia = 5-(tert-butyl)isophthalic acid) were obtained by hydrothermal reactions and structurally characterized. Complexes 1 and 2 have a 6-connected 3D architecture and with several point symbols of (36·46·53). Complex 3 features a 5-connected 3D net structure with a point symbol of (5·69). Complex 4 possesses a 4-connected 2D net with a vertex symbol of (44·62). Complex 5 is a 3-connected 2D network with a point symbol of (63). Complex 6 is a (3,3)-connected 2D network with a point symbol of (63)2. In addition, complexes 1 and 4 present good photoluminescence behaviors. The electronic structures of 1 and 4 were investigated with the density functional theory (DFT) method to understand the photoluminescence behaviors.

Endothelial depletion of Atg7 triggers astrocyte-microvascular disassociation at blood-brain barrier.

Microvascular basement membrane (BM) plays a pivotal role in the interactions of astrocyte with endothelium to maintain the blood-brain barrier (BBB) homeostasis; however, the significance and precise regulation of the endothelial cell-derived BM component in the BBB remain incompletely understood. Here, we report that conditional knockout of Atg7 in endothelial cells (Atg7-ECKO) leads to astrocyte-microvascular disassociation in the brain. Our results reveal astrocytic endfeet detachment from microvessels and BBB leakage in Atg7-ECKO mice. Furthermore, we find that the absence of endothelial Atg7 downregulates the expression of fibronectin, a major BM component of the BBB, causing significantly reduced coverage of astrocytes along cerebral microvessels. We reveal Atg7 triggers the expression of endothelial fibronectin via regulating PKA activity to affect the phosphorylation of cAMP-responsive element-binding protein. These results suggest that Atg7-regulated endothelial fibronectin production is required for astrocytes adhesion to microvascular wall for maintaining the BBB homeostasis. Thus, endothelial Atg7 plays an essential role in astrocyte-endothelium interactions to maintain the BBB integrity.

Study on Fluorescence Recognition of Fe3+, Cr2O72- and p-Nitrophenol by a Cadmium Complex and Related Mechanism.

The effective detection of environmental pollutants is very important to the sustainable development of human health and the environment. A luminescent Cd(II) coordination complex, {[Cd(dbtdb)(1,2,4-H3btc)]·0.5H2O}n (1) (dbtdb = 1-(2,3,5,6-tetramethyl-4-((2-(thiazol-4-yl)-2H-benzo[d]imidazol-3(3aH)-yl)methyl)benzyl)-2,7a-dihydro-2-(thiazol-4-yl)-1H-benzo[d]imidazole, 1,2,4-H3btc = 1,2,4-benzenetricarboxylic acid), was obtained by hydrothermal reactions. Complex 1 has a chain structure decorated with uncoordinated Lewis basic O and S donors and provides good sensing of Fe3+, Cr2O72-, and p-nitrophenol with fluorescence quenching through an energy transfer process. The calculated binding constants were 3.3 × 103 mol-1 for Fe3+, 2.36 × 104 mol-1 for Cr2O72-, and 9.3 × 103 mol-1 for p-nitrophenol, respectively. These results show that 1 is a rare multiresponsive sensory material for efficient detection of Fe3+, Cr2O72-, and p-nitrophenol.

Monocyte-to-lymphocyte ratio is significantly associated with positive QuantiFERON-TB Gold-In-Tube and adult survival: an observational study.

This study aimed to find significant factors associated with tuberculosis (TB) infection and disease development. The participants were from National Health and Nutrition Examination Survey (NHANES) and National Death Index (NDI). The tuberculosis infection was defined as a positive QuantiFERON-TB Gold-In-Tube (QFT-GIT). The Least Absolute Shrinkage and Selection Operator (LASSO) model was used to screen variables associated with QFT-GIT among 23 laboratory measures. Then the logistic regression analyses were performed to assess the independent factors, followed by a comprehensive nomogram model construction. Receiver operating characteristic (ROC) and Decision Curve (DCA) analyses were used to assess the performance of comprehensive model on QFT-GIT result and death risk. Of 5256 individuals included, 521 individuals had positive QFT-GIT. LASSO analysis indicated that 11 variables were associated with QFT-GIT result, and logistic regression analyses further found sodium and monocyte-to-lymphocyte ratio (MLR) were independent factors. After adjusting for potential confounders, the correlation of sodium and MLR with QFT-GIT result was still observed. The comprehensive model based on sodium, MLR, and important clinical characteristics can predict 0.8 probability of positive QFT-GIT and achieve more clinical net benefit. ROC analysis by training and validation sets showed the favorable prediction performance. Comprehensive model also presented favorable performance in evaluating the death risk of individuals with positive QFT-GIT. We also found MLR rather than sodium was independently related to the death risk. Both MLR itself and comprehensive model were all significantly related to the positive QFT-GIT and death risk, which might participate in the initiation and progression of tuberculosis infection.

Evolution of the CBL and CIPK gene families in Medicago: genome-wide characterization, pervasive duplication, and expression pattern under salt and drought stress.

BACKGROUND: Calcineurin B-like proteins (CBLs) are ubiquitous Ca2+ sensors that mediate plant responses to various stress and developmental processes by interacting with CBL-interacting protein kinases (CIPKs). CBLs and CIPKs play essential roles in acclimatization of crop plants. However, evolution of these two gene families in the genus Medicago is poorly understood. RESULTS: A total of 68 CBL and 135 CIPK genes have been identified in five genomes from Medicago. Among these genomes, the gene number of CBLs and CIPKs shows no significant difference at the haploid genome level. Phylogenetic and comprehensive characteristic analyses reveal that CBLs and CIPKs are classified into four clades respectively, which is validated by distribution of conserved motifs. The synteny analysis indicates that the whole genome duplication events (WGDs) have contributed to the expansion of both families. Expression analysis demonstrates that two MsCBLs and three MsCIPKs are specifically expressed in roots, mature leaves, developing flowers and nitrogen fixing nodules of Medicago sativa spp. sativa, the widely grown tetraploid species. In particular, the expression of these five genes was highly up-regulated in roots when exposed to salt and drought stress, indicating crucial roles in stress responses. CONCLUSIONS: Our study leads to a comprehensive understanding of evolution of CBL and CIPK gene families in Medicago, but also provides a rich resource to further address the functions of CBL-CIPK complexes in cultivated species and their closely related wild relatives.

An oxygen-adaptive interaction between SNHG12 and occludin maintains blood-brain barrier integrity.

Tight junctions (TJs) of brain microvascular endothelial cells (BMECs) play a pivotal role in maintaining the blood-brain barrier (BBB) integrity; however, precise regulation of TJs stability in response to physiological and pathological stimuli remains elusive. Here, using RNA immunoprecipitation with next-generation sequencing (RIP-seq) and functional characterization, we identify SNHG12, a long non-coding RNA (lncRNA), as being critical for maintaining the BBB integrity by directly interacting with TJ protein occludin. The interaction between SNHG12 and occludin is oxygen adaptive and could block Itch (an E3 ubiquitin ligase)-mediated ubiquitination and degradation of occludin in human BMECs. Genetic ablation of endothelial Snhg12 in mice results in occludin reduction and BBB leakage and significantly aggravates hypoxia-induced BBB disruption. The detrimental effects of hypoxia on BBB could be alleviated by exogenous SNHG12 overexpression in brain endothelium. Together, we identify a direct TJ modulator lncRNA SNHG12 that is critical for the BBB integrity maintenance and oxygen adaption.

Corrigendum: Potential Mechanisms of Action of Chinese Patent Medicines for COVID-19: A Review.

[This corrects the article DOI: 10.3389/fphar.2021.668407.].

Potential Mechanisms of Action of Chinese Patent Medicines for COVID-19: A Review.

Coronavirus disease 2019 (COVID-19) is an emergent infectious pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is highly contagious and pathogenic. COVID-19 has rapidly swept across the world since it was first discovered in December 2019 and has drawn significant attention worldwide. During the early stages of the outbreak in China, traditional Chinese medicines (TCMs) were involved in the whole treatment process. As an indispensable part of TCM, Chinese patent medicines (CPMs) played an irreplaceable role in the prevention and treatment of this epidemic. Their use has achieved remarkable therapeutic efficacy during the period of medical observation and clinical treatment of mild, moderate, severe, and critical cases and during convalescence. In order to better propagate and make full use of the benefits of TCM in the treatment of COVID-19, this review will summarize the potential target of SARS-CoV-2 as well as the theoretical basis and clinical efficacy of recommended 22 CPMs by the National Health Commission and the Administration of TCM and local provinces or cities in the treatment of COVID-19. Additionally, the study will further analyze the drug composition, potential active ingredients, potential targets, regulated signaling pathways, and possible mechanisms for COVID-19 through anti-inflammatory and immunoregulation, antiviral, improve lung injury, antipyretic and organ protection to provide meaningful information about the clinical application of CPMs.

A review on the efficacy and safety of iodine-125 seed implantation in unresectable pancreatic cancers.

Background: Pancreatic cancers are the common digestive system tumors with poor prognosis and due to its late diagnosis, surgical resection does not remain a viable treatment option in about 80% of patients. Amongst different treatment options, radioactive 125I seed implantation therapy has also emerged as a good alternative in non-resectable pancreatic cancer patients.Purpose: The present review describes the efficacy and safety of iodine-125 seed implantation in unresectable pancreatic cancers in preclinical and clinical studies.Results: In this technique, small radioactive particles are implanted inside the tumor cells to produce the sustain effects. Due to the short radial distance of these radiations, there is a selective and efficient killing of cancer cells without any significant injury to the neighboring cells. Amongst the different methods for implanting 125I seeds in the pancreatic tissues, CT scan or ultrasound-guided percutaneous seed implantation is preferred as it offers shorter operative time, lesser bleeding, early recovery, lesser complications, and low medical costs. The clinical studies have shown that radioactive 125I seed implantation is a good option for the management of local tumor growth, pain palliation, and improvement in the life span of patients suffering from unresectable pancreatic cancer.Conclusion: It may be employed either alone or in combination with cryotherapy, existing chemotherapy, bypass surgery or radiations to achieve the optimal results in these patients. Nevertheless, there is a need to formulate a uniform dose and procedure to achieve homogeneity and develop references for clinical practices.

Enhancing cytotoxicity of daunorubicin on drug-resistant leukaemia cells with microparticle-mediated drug delivery system.

Multidrug resistance is considered as a major obstacle for effective tumour chemotherapy. With the ability to deliver drugs into tumour cells, microparticles may act as a drug delivery vehicle to overcome drug resistance. In the present study, we developed an approach employing daunorubicin-loaded microparticles to surmount the drug resistance in leukaemia. The microparticles, derived from the drug-sensitive cells K562 and the drug-resistant cells K562/ADR, composed of cellular material, can effectively package drugs using intracellular and extracellular drug-loading method, respectively. The results demonstrated that the microparticles significantly improved the drug anti-tumour effect, which was influenced by the preparation methods and the source of donor cells. We further confirmed that the uptake of microparticles is mediated by an energy-driven endocytic process and mainly associated with clathrin-independent endocytosis and macropinocytosis. These results indicated that the microparticle could serve as a promising drug vehicle for the treatment of drug-resistant leukaemia.

Continuous Passive Motion After Total Knee Arthroplasty: A Systematic Review and Meta-analysis of Associated Effects on Clinical Outcomes.

OBJECTIVE: To evaluate the efficacy of continuous passive motion (CPM) after total knee arthroplasty (TKA) and whether the use of CPM is related to improved clinical and functional outcomes. DATA SOURCES: A systematic MEDLINE search via Web of Science, Cochrane Library, and PubMed databases was conducted. STUDY SELECTION: English-language articles published between January 2000 and May 2018 reporting the related clinical outcomes of CPM after TKA were included. A total of 3334 titles and abstracts were preliminarily reviewed, of which 16 studies were included according to the eligibility criteria. DATA EXTRACTION: Two different reviewers were selected to perform the study extraction, independent of each other. If there were any disagreements regarding the final list of studies, the third reviewer reviewed the list as an arbitrator for completeness. DATA SYNTHESIS: A total of 16 trials with 1224 patients were included. The pooled results revealed that use of CPM did not show a statistically significant improvement of postoperative knee range of motion (ROM) except for middle-term passive knee extension and long-term active knee flexion ROM. Also, CPM therapy did not show a significant positive effect on the functional outcomes. No significant reduction in length of stay (LOS) and incidence of adverse events (AEs) was identified. CONCLUSION: Among patients undergoing TKA, neither the ROM nor the functional outcomes could be improved by CPM therapy. Moreover, the risk of AEs and LOS could not be reduced by application of CPM. The current available evidence suggested that this intervention was insufficient to be used routinely in clinical practice.

Endothelial Atg7 Deficiency Ameliorates Acute Cerebral Injury Induced by Ischemia/Reperfusion.

Ischemic strokes often result in cerebral injury due to ischemia/reperfusion (I/R). Although the local inflammatory responses are known to play a primary role in the brain I/R injury, the underlying mechanism remains unclear. In the current study, we investigated the effect of brain endothelial Atg7 (autophagy related 7) depletion in the acute brain injury induced by ischemia and reperfusion. Endothelial knockout of Atg7 in mice (Atg7 eKO) was found to significantly attenuate both the infarct volume and the neurological defects induced by I/R when compared to the controls. In fact, brain inflammatory responses induced by I/R were alleviated by the Atg7 eKO. Furthermore, an increased expression of pro-inflammatory cytokines, including IL-1ß, IL-6, IL-8, and TNF-α, was observed in brain endothelial cells in response to oxygen/glucose depletion/reoxygenation, which was decreased by the shRNA-mediated Atg7 knockdown. Interestingly, Atg7 knockdown reduced IKKß phosphorylation, leading to NF-κB deactivation and downregulation of the pro-inflammatory cytokines mRNA levels. Further, Atg7 transcriptional regulation function is independent of its role in autophagy. Taken together, our results demonstrated that brain endothelial Atg7 contributes to brain damage during I/R by modulating the expression of pro-inflammatory cytokines. Depletion of Atg7 in brain endothelium has a neuroprotective effect against the ischemia/reperfusion-induced acute cerebral injury during stroke.

Prognostic and predictive value of serum carcinoembryonic antigen levels in advanced non-small cell lung cancer patients with epidermal growth factor receptor sensitive mutations and receiving tyrosine kinase inhibitors.

BACKGROUND: Despite the widespread use of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in advanced or recurrent non-small cell lung cancer (NSCLC), no biomarkers for predicting the efficacy of EGFR-TKIs in patients with EGFR-sensitive mutations have yet been identified. The purpose of our study was to explore the effect of baseline serum tumor markers in stage IIIB/IV NSCLC patients treated with EGFR-TKIs. METHODS: One hundred and seventy-seven patients with stage IIIB/IV NSCLC who harbored EGFR-sensitive mutations and were treated with EGFR-TKIs were retrospectively reviewed. Their levels of CEA, CYFRA 21-1, NSE and CA199 were measured before treatment with EGFR-TKIs. RESULTS: The response rate for all patients was 54.8%, with a median progression-free survival of 6.6 months and overall survival of 14.8 months. In univariate analyses, patients with CEA levels below the cutoff point (10 ng/ml) had higher RR, better PFS, and better OS than those with CEA levels above 10 ng/mL (RR: 69.2% vs. 43.4%, p= 0.001; mPFS: 7.8 months vs. 5.3 months, p=0.029; mOS: 18.8 months vs. 11.8 months, p=0.000). The baseline serum CEA level was an independent factor for RR (odds ratio [OR] =0.322, p=0.001), PFS (hazard ratio [HR] =1.45, p=0.025), and OS (HR=2.133, p=0.000). CONCLUSION: Our study suggests that baseline serum CEA levels may play a role in predicting the efficacy of EGFR-TKIs in stage IIIB/IV NSCLC patients with EGFR-sensitive mutations who are treated with EGFR-TKIs.

Identification and optimization of novel 6-acylamino-2-aminoquinolines as potent Hsp90 C-terminal inhibitors.

In order to discover novel Hsp90 inhibitors targeting the C-terminal ATP binding pocket, a novobiocin derivative based ROCS model was constructed for virtual screening. Compound 13 was identified as the lead compound and then systematical structure activity relationship (SAR) study was conducted. These efforts led to compound 69, which exhibited potent anti-proliferative activities against MCF7 and SKBr3 breast cancer cell lines. In 4T1 mice breast cancer models, 69 exhibited potent tumor growth inhibition and anti-metastasis effect. Compound 69 as a potent antitumor agent targeting the Hsp90 C-terminal is worthy of further pre-clinical study.

[Preparation and antitumor effects of tanshinone â ¡A loaded albumin nanoparticles].

In this study, the tanshinone ⅡA loaded albumin nanoparticles were prepared by high pressure homogenization method. The formulation was optimized by central composite design-response surface method (CCD-RSM), with the particle size, encapsulation efficiency, and drug loading as indexes to investigate their in vitro anti-tumor effect. The results showed that the prepared nanoparticles had uniformly spherical morphology and uniform particle size distribution. The average particle size, encapsulation efficiency and drug loading of nanoparticles were about (175.7± 3.07) nm, 90.8%±1.47% and 5.52%±0.09%, respectively. Tanshinone ⅡA loaded albumin nanoparticles showed a more powerful antitumor effect than free tanshinone ⅡA for human promyelocytic leukemia NB4 cells. The preparation method of the drug-loaded albumin nanoparticles was simple and easy, and can significantly improve the solubility of tanshinone ⅡA, so it was helpful to extend its application in therapies against hematological malignancies.

Significance of glucocorticoid receptor expression in patients with non-small cell lung cancer treated with pemetrexed-based chemotherapy.

BACKGROUND: Pemetrexed is the preferred chemotherapy agent in the management of non-squamous non-small cell lung cancer (non-sq-NSCLC), but lacks biomarkers predicting its efficacy. Dexamethasone, one of the premedications of pemetrexed, may downregulate p53 through the glucocorticoid receptor (GR). The purpose of our study was to explore the effect of GR in peripheral blood mononuclear cells (PBMC) and its role in predicting pemetrexed efficacy. METHODS: In all, 122 patients with stage IV non-sq-NSCLC who received first-line pemetrexed-containing chemotherapy were retrospectively reviewed. The expression of GR in PBMC was measured before treatment with pemetrexed using real-time PCR was used to detect the levels of GRα and GRß. RESULTS: The response rate for all patients was 38.5%, with a median progression-free survival (PFS) of 5.9 months and overall survival (OS) of 14.3 months. In univariate analyses, patients with a low GRα/GRß ratio in PBMC had higher RR, better PFS, and better OS than those with a high GRα/GRß ratio (RR: 48.2 vs. 30.3%, p = 0.043; mPFS: 6.9 vs. 4.0 months, p < 0.001; mOS: 18.7 vs. 12.2 months, p = 0.005). The baseline GRα/GRß ratio was an independent factor for RR (odds ratio [OR] = 0.451, 95% CI 0.208-0.978; p = 0.044), PFS (HR = 1.584, 95% CI 1.094-2.295; p = 0.015), and OS (HR = 1.761, 95% CI 1.195-2.595; p = 0.004). CONCLUSIONS: Baseline GRα/GRß ratio in PBMC may play a role in predicting the efficacy of first-line pemetrexed-containing chemotherapy in stage IV non-sq NSCLC patients.

Atg7 Regulates Brain Angiogenesis via NF-κB-Dependent IL-6 Production.

The formation of brain vasculature is an essential step during central nervous system development. The molecular mechanism underlying brain angiogenesis remains incompletely understood. The role of Atg7, an autophagy-related protein, in brain angiogenesis was investigated in this study. We found that the microvessel density in mice brains with endothelial-specific knockout of Atg7 (Atg7 EKO) was significantly decreased compared to wild-type control. Consistently, in vitro angiogenesis assays showed that Atg7 knockdown impaired angiogenesis in brain microvascular endothelial cells. Further results indicated that knockdown of Atg7 reduced interleukin-6 (IL-6) expression in brain microvascular endothelial cells, which is mediated by NF-κB-dependent transcriptional control. Interestingly, exogenous IL-6 restored the impaired angiogenesis and reduced cell motility caused by Atg7 knockdown. These results demonstrated that Atg7 has proangiogenic activity in brain angiogenesis which is mediated by IL-6 production in a NF-κB-dependent manner.

A novel bispecific c-MET/PD-1 antibody with therapeutic potential in solid cancer.

The bispecific antibody is a novel antibody, which can target two different antigens and mediate specific killing effects by selectively redirecting effector cells to the target cells. Here, we designed and synthesized a bispecific antibody (BsAb) that can bind cellular-mesenchymal to epithelial transition factor (c-MET, overexpressed in several human solid tumor), and programmed death-1 (PD-1, involved in cancer cell immune evasion) with high affinity and specificity. We found that BsAb can induce the degradation of c-MET protein in cancer cells, including MKN45, a gastric cancer cell line, and A549, a lung cancer cell line. BsAb inhibited hepatocyte growth factor (HGF)-mediated proliferation, migration, and antiapoptosis, and downregulated HGF-stimulated phosphorylation of c-MET, protein kinase B (AKT), and extracellular signal-regulated kinase (ERK1/2). BsAb can also rescue T cell activation. Furthermore, xenograft analysis revealed that BsAb markedly inhibits the growth of subcutaneously implanted tumors and chronic inflammation. On the basis of these results, we have identified a potential bispecific drug, which can effectively target c-MET and PD-1 for the treatment of human solid cancers.

Novel Tetrahydropyrido[4,3-d]pyrimidines as Potent Inhibitors of Chaperone Heat Shock Protein 90.

Heat shock protein 90 (Hsp90) is a potential target for oncology therapeutics. Some inhibitors have shown antitumor effects in clinical trials, spurring the discovery of small molecule Hsp90 inhibitors. Here, we describe the structural optimization studies of a hit compound, tetrahydropyrido[4,3-d]pyrimidine-based Hsp90 inhibitor 15, which exhibits inhibitory activity against Hsp90. A series of analogues were synthesized, and their structure-activity and structure-property relationships were analyzed. These explorations led to the discovery of compound 73, which exhibited potent in vitro activities, good physicochemical properties, favorable ADME properties, and a potent antitumor effect in an HCT116 xenograft model. Furthermore, 73 exhibited no ocular toxicity in a rat retinal damage model, suggesting it is a relatively safe Hsp90 inhibitor. As a promising antitumor agent, 73 was progressed for further preclinical evaluation.