Emerging Links between Control of Mitochondrial Protein ATAD3A and Cancer.

Spanning from the mitochondria's outer surface to the inner membrane, the nuclear-encoded protein ATAD3A maintains vital roles in regulating mitochondrial dynamics, homeostasis, metabolism, and interactions with the endoplasmic reticulum. Recently, elevated levels of ATAD3A have been reported in several types of cancer and to be tightly correlated with cancer development and progression, including increased cancer cell potential of proliferation, metastasis, and resistance to chemotherapy and radiotherapy. In the current review, we reveal ATAD3A as the link between mitochondrial functions and cancer biology and the accumulating evidence presenting ATAD3A as an attractive target for the development of novel cancer therapy to inhibit aberrant cancer metabolism and progression.

Intracellular reduction in ATP levels contributes to CYT997-induced suppression of metastasis of head and neck squamous carcinoma.

The incidence rate of head and neck squamous cell carcinoma (HNSCC) has steadily increased over the past decade. However, treatment options for metastatic HNSCC are often limited and the 5-year survival rate has remained static. Therefore, the development and assessment of more efficient but less toxic therapeutic strategies is an unmet need for treatment of more extensive HNSCC. Here, we report that CYT997, a novel microtubule-disrupting agent, exerts strong activity in inhibiting HNSCC cell invasion and metastasis. The loss of invasion capacity by CYT997 was accompanied by an associated increase in cell adhesion and the reversal of epithelial-mesenchymal transition (EMT). Increased expression of E-cadherin protein and decreased expression of Vimentin protein became evident in HNSCC cells following CYT997 exposure, which were consistently observed in HNSCC xenografts from the mice receiving CYT997. Moreover, the capacity of invasive HNSCC cells to form pulmonary metastases was significantly blocked with CYT997 treatment, indicating that the diminishment of EMT traits contributes to CYT997-suppressed metastasis. Intriguingly, CYT997 impaired intracellular ATP levels in HNSCC cells, at least in part, through its inhibitory effect on the mitochondrial protein IF1. The addition of ATP attenuated CYT997-induced suppression of cell invasion, coupled with down-regulation of E-Cadherin and up-regulation of Vimentin. These findings support a critical role of ATP levels in cell invasion and metastasis under the influence of CYT997. Collectively, our data unveil the mechanism involved in mediating CYT997 action, and provide preclinical rationale for possible clinical application of CYT997 as a novel therapeutic strategy against aggressive HNSCC.

ATAD3A on the Path to Cancer.

The ATPase family AAA-domain containing protein 3A (ATAD3A), a nuclear-encoded mitochondrial enzyme, is involved in diverse cellular processes, including mitochondrial dynamics, cell death and cholesterol metabolism. Overexpression and/or mutation of the ATAD3A gene have been observed in different types of cancer, associated with cancer development and progression. The dysregulated ATAD3A acts as a broker of a mitochondria-endoplasmic reticulum connection in cancer cells, and inhibition of this enzyme leads to tumor repression and enhanced sensitivity to chemotherapy and radiation. As such, ATAD3A is a promising drug target in cancer treatment.

PFKP Signaling at a Glance: An Emerging Mediator of Cancer Cell Metabolism.

Phosphofructokinase-1 (PFK-1), a rate-determining enzyme of glycolysis, is an allosteric enzyme that regulates the oxidation of glucose in cellular respiration. Glycolysis phosphofructokinase platelet (PFKP) is the platelet isoform and works as an important mediator of cell metabolism. Considering that PFKP is a crucial player in many steps of cancer initiation and metastasis, we reviewed the specificities and complexities of PFKP and its biological roles in human diseases, especially malignant tumors. The possible use of PFKP as a diagnostic marker or a drug target in the prevention or treatment of cancer is also discussed.

Pharmacokinetics and pharmacodynamics of intravenous ilaprazole in healthy subjects after single ascending doses.

1. Ilaprazole is a novel proton pump inhibitor and this is the first study to investigate the pharmacokinetics, pharmacodynamics and safety of intravenous ilaprazole in healthy volunteers. 2. In this open-label, single-dose, randomized and four-period crossover study, 16 healthy Chinese subjects received ilaprazole 5, 10 or 20 mg intravenously, or 10 mg orally. Serial blood and urine samples were collected and intragastric pH was recorded within 24 h. The percentage time of intragastric pH > 6 was the major index. Safety was assessed throughout the study. 3. Plasma exposure of intravenous ilaprazole increased proportionally over the dose of 5-20 mg. Clearance and volume of distribution were independent of dose. Ilaprazole was not eliminated through urine and the absolute bioavailability was 55.2%. For the intravenous dose of 5, 10, 20 mg, and oral dose of 10 mg, the mean percentages time of intragastric pH > 6 were 47.3%, 52.8%, 68.2% and 47.5%, respectively. 4. Ilaprazole showed linear pharmacokinetics over the dose of 5-20 mg. Intravenous ilaprazole provided rapid onset of action and the potency of effect were exhibited in a dose-dependent manner. Intravenous ilaprazole was safe and well tolerated except for elevated activated partial thromboplastin time (APTT) and prothrombin time (PT).

Intrapulmonary concentration of levofloxacin in patients with idiopathic pulmonary fibrosis.

Patients with idiopathic pulmonary fibrosis (IPF) have significantly impaired pulmonary diffusion, which may affect the pulmonary concentration of many drugs, including antibiotics. In this study, we compared the difference in pulmonary levofloxacin (LVFX) concentration between patients with normal lung function and IPF. The IPF group included 10 patients with a proven diagnosis of IPF and a diffusing capacity for carbon monoxide ranging from 40% to 70% of predicted values. The control group included 10 patients with normal pulmonary function. Blood and bronchoalveolar lavage fluid (BALF) were taken at 3-3.5 h after fasting. LVFX (500 mg) was administered orally. LVFX concentrations in the serum and BALF were determined using HPLC-MS/MC. The level of LVFX in alveolar epithelial lining fluid (ELF) was calculated using the following formula: LVFX ELF = LVFX BALF × (Urea serum/Urea BALF). No significant differences in age, body weight, height, and calculated creatinine clearance and BALF retrieval rate were observed between groups. LVFX serum concentrations in the IPF and control groups were (5.97 ± 1.28) µg/ml and (6.84 ± 3.43) µg/ml, respectively (P = 0.4727). ELF concentration of LVFX in the control group was (27.81 ± 21.36) µg/ml, while the concentration in the IPF group was (10.17 ± 2.46) µg/ml, less than half of that in the controls (P = 0.0058). The intrapulmonary concentration of LVFX in IPF patients was lower than those with normal lung function. Notably, however, the ELF LVFX concentration following 500 mg once-daily exceeded the MIC90 of common respiratory pathogens. Excellent antibacterial efficacy of LVFX can be expected for IPF patients in the treatment of respiratory tract infections.

[A novel HIF-1 inhibitor--manassantin A derivative LXY6099 inhibits tumor growth].

Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor on hypoxia responses in mammalian tissues. HIF-1 plays as a positive factor in solid tumor and leads to hypoxia-driven responses that enhance its downstream gene expression for tumor growth and survival. LXY6099 was obtained by the structural modification and optimization of manassantin A (MA) as a high potent HIF-1 inhibitor. Antitumor activity of LXY6099 was observed in this study. LXY6099 with an IC50 value of 2.46 x 10(-10) mol x L(-1) showed more sensitive inhibition activity to HIF-1 than that of MA detected by reporter gene assay (> 100 folds). It showed strong inhibition on the growth of human solid tumor cell lines. Furthermore, LXY6099 exhibited significant antitumor activity against established human tumor xenografts in nu/nu mice with treatment of MX-1 breast cancer. Thus, LXY6099 as a novel HIF-1 inhibitor could be further developed into anti-cancer agents.

Phosphodiesterase 9A inhibition improves aging-related increase in pulmonary vascular resistance in mice.

As individuals age, there is a gradual decline in cardiopulmonary function, often accompanied by cardiac pump dysfunction leading to increased pulmonary vascular resistance (PVR). Our study aims to investigate the changes in cardiac and pulmonary vascular function associated with aging. Additionally, we aim to explore the impact of phosphodiesterase 9A (PDE9A) inhibition, which has shown promise in treating cardiometabolic diseases, on addressing left ventricle (LV) dysfunction and elevated PVR in aging individuals. Young (3 months old) and aged (32 months old) male C57BL/6 mice were used. Aged mice were treated with the selective PDE9A inhibitor PF04447943 (1 mg/kg/day) through intraperitoneal injections for 10 days. LV function was evaluated using cardiac ultrasound, and PVR was assessed in isolated, ventilated lungs perfused under a constant flow condition. Additionally, changes in PVR were measured in response to perfusion of the endothelium-dependent agonist bradykinin or to nitric oxide (NO) donor sodium nitroprusside (SNP). PDE9A protein expression was measured by Western blots. Our results demonstrate the development of LV diastolic dysfunction and increased PVR in aged mice. The aged mice exhibited diminished decreases in PVR in response to both bradykinin and SNP compared to the young mice. Moreover, the lungs of aged mice showed an increase in PDE9A protein expression. Treatment of aged mice with PF04447943 had no significant effect on LV systolic or diastolic function. However, PF04447943 treatment normalized PVR and SNP-induced responses, though it did not affect the bradykinin response. These data demonstrate a development of LV diastolic dysfunction and increase in PVR in aged mice. We propose that inhibitors of PDE9A could represent a novel therapeutic approach to specifically prevent aging-related pulmonary dysfunction.

Therapeutic Targeting of the GLS1-c-Myc Positive Feedback Loop Suppresses Glutaminolysis and Inhibits Progression of Head and Neck Cancer.

Head and neck squamous cell carcinoma (HNSCC) is addicted to glutaminolysis. Targeting this metabolic dependency has emerged as a potential therapeutic approach for HNSCC. Here, we conducted a bioinformatic analysis of the TCGA HNSCC cohort that revealed a robust correlation between expression of c-Myc and GLS1, which catalyzes the first step in glutaminolysis. Intriguingly, disruption of GLS1 signaling in HNSCC cells by genetic depletion or CB-839 treatment resulted in a reduction in c-Myc protein stability via a USP1-dependent ubiquitin-proteasome pathway. On the other hand, c-Myc directly binds to the promoter region of GLS1 and upregulates its transcription. Notably, the GLS1-c-Myc pathway enhanced ACC-dependent SLUG acetylation, prompting cancer cell invasion and metastasis. Thus, the GLS1-c-Myc axis emerged as a positive feedback loop critical for driving the aggressiveness of HNSCC. Therapeutically, combining CB-839 with the c-Myc inhibitor MYCi975 strongly suppressed GLS1-c-Myc signaling, resulting in a superior antitumor effect compared to either single agent in an orthotopic mouse model of HNSCC. These findings hold promise for the development of effective therapies for HNSCC patients, addressing an urgent need arising from the significant incidence and high metastatic rate of the disease.

Modulation of Dendritic Cell Function via Nanoparticle-Induced Cytosolic Calcium Changes.

Calcium nanoparticles have been investigated for applications, such as drug and gene delivery. Additionally, Ca2+ serves as a crucial second messenger in the activation of immune cells. However, few studies have systematically studied the effects of calcium nanoparticles on the calcium levels and functions within immune cells. In this study, we explore the potential of calcium nanoparticles as a vehicle to deliver calcium into the cytosol of dendritic cells (DCs) and influence their functions. We synthesized calcium hydroxide nanoparticles, coated them with a layer of silica to prevent rapid degradation, and further conjugated them with anti-CD205 antibodies to achieve targeted delivery to DCs. Our results indicate that these nanoparticles can efficiently enter DCs and release calcium ions in a controlled manner. This elevation in cytosolic calcium activates both the NFAT and NF-κB pathways, in turn promoting the expression of costimulatory molecules, antigen-presenting molecules, and pro-inflammatory cytokines. In mouse tumor models, the calcium nanoparticles enhanced the antitumor immune response and augmented the efficacy of both radiotherapy and chemotherapy without introducing additional toxicity. Our study introduces a safe nanoparticle immunomodulator with potential widespread applications in cancer therapy.

Synthesis and biopharmaceutical studies of JLTN as potential dasatinib prodrug.

Dasatinib was identified as a potent orally administered Src/Abl kinase inhibitor with excellent antiproliferative activity against Philadelphia chromosome-positive chronic myelogenous leukemia in chronic phase. The low bioavailability of Dasatinib may be due to both incomplete oral absorption and first-pass metabolism. A prodrug, JLTN, was synthesized to minimize the first-pass effect of Dasatinib and improve the oral bioavailability following oral administration via targeting intestinal peptide transporter and enhancing chemical stability. Biological evaluation data indicated that there was a 150%-fold increase in oral bioavailability of this prodrug compared to the parent drug Dasatinib in monkeys.

Home visits in brain tumor patient: how nurse and family members cooperate in tumor patient's family self-care.

PURPOSES: We reported the roles and functions of nurses in home visits for brain tumor patients using the family health assessment guide in the study. METHODS: One patient of brain glioma was chosen as the case illustration. The nurses assessed the patients' situation, their families and living environment individually. All these factors were analyzed together. RESULTS: The nurses then implemented their knowledge and skills to adopt different measures in different conditions, investigated the patients' health problems and carried out personalized effective actions. CONCLUSIONS: Nurses should put effort into community nursing to allow patients to live in a safe environment, to satisfy the health needs of human being and their needs for health knowledge, and enhance their self-care abilities.

Adaptive c-Met-PLXDC2 Signaling Axis Mediates Cancer Stem Cell Plasticity to Confer Radioresistance-associated Aggressiveness in Head and Neck Cancer.

Radiotherapy plays an essential role in the treatment of head and neck squamous cell carcinoma (HNSCC), yet radioresistance remains a major barrier to therapeutic efficacy. A better understanding of the predominant pathways determining radiotherapy response could help develop mechanism-informed therapies to improve cancer management. Here we report that radioresistant HNSCC cells exhibit increased tumor aggressiveness. Using unbiased proteome profiler antibody arrays, we identify that upregulation of c-Met phosphorylation is one of the critical mechanisms for radioresistance in HNSCC cells. We further uncover that radioresistance-associated HNSCC aggressiveness is effectively exacerbated by c-Met but is suppressed by its genetic knockdown and pharmacologic inactivation. Mechanistically, the resulting upregulation of c-Met promotes elevated expression of plexin domain containing 2 (PLXDC2) through activating ERK1/2-ELK1 signaling, which in turn modulates cancer cell plasticity by epithelial-mesenchymal transition (EMT) induction and enrichment of the cancer stem cell (CSC) subpopulation, leading to resistance of HNSCC cells to radiotherapy. Depletion of PLXDC2 overcomes c-Met-mediated radioresistance through reversing the EMT progress and blunting the self-renewal capacity of CSCs. Therapeutically, the addition of SU11274, a selective and potent c-Met inhibitor, to radiation induces tumor shrinkage and limits tumor metastasis to lymph nodes in an orthotopic mouse model. Collectively, these significant findings not only demonstrate a novel mechanism underpinning radioresistance-associated aggressiveness but also provide a possible therapeutic strategy to target radioresistance in patients with HNSCC. Significance: This work provides novel insights into c-Met-PLXDC2 signaling in radioresistance-associated aggressiveness and suggests a new mechanism-informed therapeutic strategy to overcome failure of radiotherapy in patients with HNSCC.

The role of ADAM17 in cerebrovascular and cognitive function in the APP/PS1 mouse model of Alzheimer's disease.

Introduction: The disintegrin and metalloproteinase 17 (ADAM17) exhibits α-secretase activity, whereby it can prevent the production of neurotoxic amyloid precursor protein-α (APP). ADAM17 is abundantly expressed in vascular endothelial cells and may act to regulate vascular homeostatic responses, including vasomotor function, vascular wall morphology, and formation of new blood vessels. The role of vascular ADAM17 in neurodegenerative diseases remains poorly understood. Here, we hypothesized that cerebrovascular ADAM17 plays a role in the pathogenesis of Alzheimer's disease (AD). Methods and results: We found that 9-10 months old APP/PS1 mice with b-amyloid accumulation and short-term memory and cognitive deficits display a markedly reduced expression of ADAM17 in cerebral microvessels. Systemic delivery and adeno-associated virus (AAV)-mediated re-expression of ADAM17 in APP/PS1 mice improved cognitive functioning, without affecting b-amyloid plaque density. In isolated and pressurized cerebral arteries of APP/PS1 mice the endothelium-dependent dilation to acetylcholine was significantly reduced, whereas the vascular smooth muscle-dependent dilation to the nitric oxide donor, sodium nitroprusside was maintained when compared to WT mice. The impaired endothelium-dependent vasodilation of cerebral arteries in APP/PS1 mice was restored to normal level by ADAM17 re-expression. The cerebral artery biomechanical properties (wall stress and elasticity) and microvascular network density was not affected by ADAM17 re-expression in the APP/PS1 mice. Additionally, proteomic analysis identified several differentially expressed molecules involved in AD neurodegeneration and neuronal repair mechanisms that were reversed by ADAM17 re-expression. Discussion: Thus, we propose that a reduced ADAM17 expression in cerebral microvessels impairs vasodilator function, which may contribute to the development of cognitive dysfunction in APP/PS1 mice, and that ADAM17 can potentially be targeted for therapeutic intervention in AD.

Mice with endothelial cell-selective adhesion molecule deficiency develop coronary microvascular rarefaction and left ventricle diastolic dysfunction.

Endothelial cell-selective adhesion molecule (ESAM) regulates inflammatory cell adhesion and transmigration and promotes angiogenesis. Here, we examined the role of ESAM in cardiac vascularization, inflammatory cell infiltration, and left ventricle (LV) diastolic function under basal and hemodynamic stress conditions. We employed mice with homozygous genetic deletion of ESAM (ESAM-/- ) and also performed uninephrectomy and aldosterone infusion (UNX-Aldo) to induce volume and pressure overload. Using echocardiography, we found that ESAM-/- mice display no change in systolic function. However, they develop LV diastolic dysfunction, as indicated by a significantly reduced E/A ratio (E = early, A = late mitral inflow peak velocities), increased E/e' ratio, isovolumic relaxation time (IVRT), and E wave deceleration time. An unbiased automated tracing and 3D reconstruction of coronary vasculature revealed that ESAM-/- mice had reduced coronary vascular density. Arteries of ESAM-/- mice exhibited impaired endothelial sprouting and in cultured endothelial cells siRNA-mediated ESAM knockdown reduced tube formation. Changes in ESAM-/- mice were accompanied by elevated myocardial inflammatory cytokine and myeloperoxidase-positive neutrophil levels. Furthermore, UNX-Aldo procedure in wild type mice induced LV diastolic dysfunction, which was accompanied by significantly increased serum ESAM levels. When compared to wild types, ESAM-/- mice with UNX-Aldo displayed worsening of LV diastolic function, as indicated by increased IVRT and pulmonary edema. Thus, we propose that ESAM plays a mechanistic role in proper myocardial vascularization and the maintenance of LV diastolic function under basal and hemodynamic stress conditions.

Lx2-32c, a novel taxane derivative, exerts anti-resistance activity by initiating intrinsic apoptosis pathway in vitro and inhibits the growth of resistant tumor in vivo.

Resistance to anticancer drugs is a major obstacle to successful chemotherapy. Thus, the exploration of new drugs and strategies in combating resistance is of great importance. In this study, we investigated the anti-tumor drug resistance (anti-resistance for short) activity of Lx2-32c, a novel taxane, and its possible mechanisms. Lx2-32c was cytotoxic to various drug-resistant tumor cell lines, and significantly suppressed the growth of tumor xenografts in paclitaxel-resistant MX-1 nude mice. It promoted microtubule polymerization and G(2)/M phase arrest in MX-1/T cells. Moreover, it induced typical apoptotic characteristics indicated by morphological changes and DNA fragmentation. Apoptosis was associated with loss of mitochondrial membrane potential, enhancement of mitochondrial cytochrome c and apoptosis-inducing factor (AIF) release, elevation of the Bax/Bcl-2 ratio, activation of caspase-9,-3 but not caspase-8 and Fas/FasL, and degradation of poly(ADP-ribose) polymerase (PARP). In conclusion, Lx2-32c is an effective microtubule-stabilizing agent in overcoming paclitaxel resistance by inducing apoptosis via the intrinsic apoptotic pathway. It also displayed robust anti-paclitaxel-resistance activity in vivo. Therefore, these findings provide new insight into the strategy to overcome resistance by manipulating dysregulated apoptosis pathway.

[Identification of two small molecule inhibitors of hypoxia-inducible factor 1 with different cell-based screening model].

OBJECTIVE: To investigate the inhibitory activity of HIF-1 by triptolide and manasaantin A, two cell-based models with luciferase report gene assay were established. METHOD: Two cell-based models of HIF-1 were used to evaluate HIF-1 inhibition activity of triptolide and manasaantin A. Secreted VEGF expression induced by hypoxia was detected by ELISA with two compounds. The growth inhibition of different solid tumor cell lines was measured by the MTT assay. RESULT: The expression of firefly luciferase was induced by hypoxia in U251-HRE and T47D-HRE cells. U251-HRE model was suitable for the detection of HIF-1 inhibition activity of triptolide. The IC50 of triptolide on HIF-1 activity was (3.4 +/- 0.5) x 10(-8) mol x L(-1). The report gene assay using T47D cells co-transfected with pGL2-TK-HRE and pRL-CMV showed more sensitive inhibition activity of HIF-1 on manassantin A than that of detected by U251-HRE model. The IC50 of manassantin A on HIF-1 activity was (2.4 +/- 0.6) x 10(-8) mol x L(-1). HIF-1 target gene VEGF was also inhibited by test compounds on protein level in T47D cells. Manasaantin A showed selective inhibition on the growth of human solid cancer cell lines, especially on breast cancer and pancreatic cancer cells. Meanwhile, triplotide showed strong proliferation inhibition activity on all tested cell lines. CONCLUSION: It is very important to select a suitable cell-based report gene assay of HIF-1 for screening of different kinds of inhibitor.

Evaluation of the Efficacy of Saracatinib-Loaded Nanoparticles in Lymphatic Metastases of HNSCC with the Aid of Bioluminescence Imaging.

Head and neck squamous cell carcinoma (HNSCC) remains a deadly disease despite concerted efforts to improve its diagnosis and treatment in recent decades. Metastasis of advanced HNSCC nearly always occurs first in neck lymph nodes before the development of distant metastasis. However, the development of preclinical animal models and therapeutic treatments for metastatic HNSCC is lagged from bench to clinic. In this protocol, we exemplify an orthotopic tongue tumor model that can recapitulate the cervical lymphatic metastases of HNSCC and the application to study the effect of novel saracatinib-loaded nanoparticles (Nano-Sar). By taking advantage of bioluminescence imaging (BLI), the present protocol reveals the strong anti-metastatic efficacy of Nano-Sar in the experimental setup. Collectively, the protocol with a novel metastatic mouse model shows great potential to evaluate treatments on metastatic diseases with the aid of bioluminescent technology.

Aging-induced impaired endothelial wall shear stress mechanosensing causes arterial remodeling via JAM-A/F11R shedding by ADAM17.

Physiological and pathological vascular remodeling is uniquely driven by mechanical forces from blood flow in which wall shear stress (WSS) mechanosensing by the vascular endothelium plays a pivotal role. This study aimed to determine the novel role for a disintegrin and metalloproteinase 17 (ADAM17) in impaired WSS mechanosensing, which was hypothesized to contribute to aging-associated abnormal vascular remodeling. Without changes in arterial blood pressure and blood flow rate, skeletal muscle resistance arteries of aged mice (30-month-old vs. 12-week-old) exhibited impaired WSS mechanosensing and displayed inward hypertrophic arterial remodeling. These vascular changes were recapitulated by in vivo confined, AAV9-mediated overexpression of ADAM17 in the resistance arteries of young mice. An aging-related increase in ADAM17 expression reduced the endothelial junction level of its cleavage substrate, junctional adhesion molecule-A/F11 receptor (JAM-A/F11R). In cultured endothelial cells subjected to steady WSS ADAM17 activation or JAM-A/F11R knockdown inhibited WSS mechanosensing. The ADAM17-activation induced, impaired WSS mechanosensing was normalized by overexpression of ADAM17 cleavage resistant, mutated JAM-AV232Y both in cultured endothelial cells and in resistance arteries of aged mice, in vivo. These data demonstrate a novel role for ADAM17 in JAM-A/F11R cleavage-mediated impaired endothelial WSS mechanosensing and subsequently developed abnormal arterial remodeling in aging. ADAM17 could prove to be a key regulator of WSS mechanosensing, whereby it can also play a role in pathological vascular remodeling in diseases.

The Association Between the Albumin and Viral Negative Conversion Rate in Patients Infected with Novel Coronavirus Disease 2019 (COVID-19).

Purpose: The novel coronavirus disease 2019 (COVID-19) epidemic is the severe global pandemic with large numbers of infected cases and deaths in recent decades. The previous studies were all about the influence of albumin (ALB) for the severity and mortality of in-patients infected with COVID-19. But few studies exist about the influence factors to achieve viral negative conversion. Therefore, this study conducted an exploratory study to investigate the effect of albumin on negative conversion rate. Methods: Among the 190 hospitalized patients with moderate COVID-19 who had a course of disease longer than 30 days, 102 achieved viral negative conversion in 30-45 days and 88 not after 45 days. Taking other variables as concomitant variable, Cox proportional hazard regression model was applied to explore the influence of albumin to negative conversion rate under various factors. Results: By comparing patients who could and could not achieve the finally viral negative conversion, a possible nonlinear relationship between the continuous variables and clinical outcomes was examined by a restricted cubic spline regression model. An association was found between albumin levels and hazard ratio of viral negative conversion rate (P = 0.027). The increase of albumin was accompanied with decreases of hazard ratio of viral negative conversion rate (the value of albumin <38 g/L). But when the value of albumin was higher than 38 g/L, the hazard ratio of viral negative conversion rate approached 1, it means that albumin is not a risk factor for the viral negative conversion rate of COVID-19 disease. Conclusion: For patients with COVID-19, albumin is a common and observed laboratory parameter. It is associated with final viral negative conversion rate although its underlying mechanism and relationship with the viral negative conversion rate still need to be clarified.