Repurposing crizotinib to target RIPK1-dependent cell death.

Receptor-interacting protein kinase 1 (RIPK1) has emerged as a key regulator of cell death and inflammation, which are implicated in the pathogenesis of many inflammatory and degenerative diseases. RIPK1 is therefore a putative therapeutic target in many of these diseases. However, no pharmacological inhibitor of RIPK1-mediated cell death is currently in clinical use. Recognizing that a repurposed drug has an expedited clinical development pipeline, here we performed a high-throughput drug screen of Food and Drug Administration (FDA)-approved compounds and identified a novel use for crizotinib as an inhibitor of RIPK1-dependent cell death. Furthermore, crizotinib rescued TNF-α-induced death in mice with systemic inflammatory response syndrome. RIPK1 kinase activity was directly inhibited by crizotinib. These findings identify a new use for an established compound and are expected to accelerate drug development for RIPK1-spectrum disorders.

Quizartinib inhibits necroptosis by targeting receptor-interacting serine/threonine protein kinase 1.

Systemic inflammatory response syndrome (SIRS), at least in part driven by necroptosis, is characterized by life-threatening multiple organ failure. Blocking the progression of SIRS and consequent multiple organ dysfunction is challenging. Receptor-interacting serine/threonine protein kinase 1 (RIPK1) is an important cell death and inflammatory mediator, making it a potential treatment target in several diseases. Here, using a drug repurposing approach, we show that inhibiting RIPK1 is also an effective treatment for SIRS. We performed cell-based high-throughput drug screening of an US Food and Drug Administration (FDA)-approved drug library that contains 1953 drugs to identify effective inhibitors of necroptotic cell death by SYTOX green staining. Dose-response validation of the top candidate, quizartinib, was conducted in two cell lines of HT-22 and MEFs. The effect of quizartinib on necroptosis-related proteins was evaluated using western blotting, immunoprecipitation, and an in vitro RIPK1 kinase assay. The in vivo effects of quizartinib were assessed in a murine tumor necrosis factor α (TNFα)-induced SIRS model. High-throughput screening identified quizartinib as the top "hit" in the compound library that rescued cells from necroptosis in vitro. Quizartinib inhibited necroptosis by directly inhibiting RIPK1 kinase activity and blocking downstream complex IIb formation. Furthermore, quizartinib protected mice against TNFα-induced SIRS. Quizartinib, as an FDA-approved drug with proven safety and efficacy, was repurposed for targeted inhibition of RIPK1. This work provides essential preclinical data for transferring quizartinib to the treatment of RIPK1-dependent necroptosis-induced inflammatory diseases, including SIRS.

Periodontitis causally affects the brain cortical structure: A Mendelian randomization study.

OBJECTIVE: To estimate whether genetically proxied periodontitis causally impacts the brain cortical structure using Mendelian randomization (MR). BACKGROUND: Periodontitis is one of the most prevalent inflammatory conditions globally, and emerging evidence has indicated its influences on distal organs, including the brain, whose disorders are always accompanied by magnetic resonance imaging (MRI)-identified brain cortical changes. However, to date, no available evidence has revealed the association between periodontitis and brain cortical structures. METHODS: The instrumental variables (IVs) were adopted from previous genome-wide association study (GWAS) studies and meta-analyses of GWAS studies of periodontitis from 1844 to 5266 cases and 8255 to 12 515 controls. IVs were linked to GWAS summary data of 51 665 patients from the ENIGMA Consortium, assessing the impacts of genetically proxied periodontitis on the surficial area (SA) or the cortical thickness (TH) of the global and 34 MRI-identified functional regions of the brain. Inverse-variance weighted was used as the primary estimate; the MR pleiotropy residual sum and outlier (MR-PRESSO), the MR-Egger intercept test, and leave-one-out analyses were used to examine the potential horizontal pleiotropy. RESULTS: Genetically proxied periodontitis affects the SA of the medial orbitofrontal cortex, the lateral orbitofrontal cortex, the inferior temporal cortex, the entorhinal cortex, and the temporal pole, as well as the TH of the entorhinal. No pleiotropy was detected. CONCLUSIONS: Periodontitis causally influences the brain cortical structures, implying the existence of a periodontal tissue-brain axis.

Targeting gut microbiota for immunotherapy of diseases.

With advances in next-generation sequencing technology, there is growing evidence that the gut microbiome plays a key role in the host's innate and adaptive immune system. Gut microbes and their metabolites directly or indirectly regulate host immune cells. Crucially, dysregulation of the gut microbiota is often associated with many immune system diseases. In turn, microbes modulate disease immunotherapy. Data from preclinical to clinical studies suggest that the gut microbiota may influence the effectiveness of tumor immunotherapy, particularly immune checkpoint inhibitors (ICIs). In addition, the most critical issue now is a COVID-19 vaccine that generates strong and durable immunity. A growing number of clinical studies confirm the potential of gut microbes to enhance the efficacy of COVID-19 vaccines. However, it is still unclear how gut bacteria interact with immune cells and what treatments are based on gut microbes. Here, we outline recent advances in the effects and mechanisms of the gut microbiota and its metabolites (tryptophan metabolites, bile acids, short-chain fatty acids, and inosine) on different immune cells (dendritic cells, CD4+T cells, and macrophages). It also highlights innovative intervention strategies and clinical trials of microbiota-based checkpoint blocking therapies for tumor immunity, and ongoing efforts to maintain the long-term immunogenicity of COVID-19 vaccines. Finally, the challenges to be overcome in this area are discussed. These provide an important basis for further research and clinical translation of gut microbiota.

CircRNA: a rising therapeutic strategy for lung injury induced by pulmonary toxicants.

Lung injury has been a serious medical problem that requires new therapeutic approaches and biomarkers. Circular RNAs (circRNAs) are non-coding RNAs (ncRNAs) that exist widely in eukaryotes. CircRNAs are single-stranded RNAs that form covalently closed loops. CircRNAs are significant gene regulators that have a role in the development, progression, and therapy of lung injury by controlling transcription, translating into protein, and sponging microRNAs (miRNAs) and proteins. Although the study of circRNAs in lung injury caused by pulmonary toxicants is just beginning, several studies have revealed their expression patterns. The function that circRNAs perform in relation to pulmonary toxicants (severe acute respiratory distress syndrome coronavirus-2 (SARS-CoV-2), drug abuse, PM2.5, and cigarette smoke) is the main topic of this review. A variety of circRNAs can serve as potential biomarkers of lung injury. In this review, the biogenesis, properties, and biological functions of circRNAs were concluded, and the relationship between circRNAs and pulmonary toxicants was discussed. It is expected that the new ideas and potential treatment targets that circRNAs provide would be beneficial to research into the molecular mechanisms behind lung injury.

From teeth to brain: dental caries causally affects the cortical thickness of the banks of the superior temporal sulcus.

OBJECTIVES: Dental caries is one of the most prevalent oral diseases and causes of tooth loss. Cross-sectional studies observed epidemiological associations between dental caries and brain degeneration disorders, while it is unknown whether dental caries causally affect the cerebral structures. This study tested whether genetically proxied DMFS (the sum of Decayed, Missing, and Filled tooth Surfaces) causally impacts the brain cortical structure using Mendelian randomization (MR). METHODS: The summary-level GWAS meta-analysis data from the GLIDE consortium were used for DMFS, including 26,792 participants. ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) consortium GWAS summary data of 51,665 patients were used for brain structure. This study estimated the causal effects of DMFS on the surface area (SA) and thickness (TH) of the global cortex and functional cortical regions accessed by magnetic resonance imaging (MRI). Inverse-variance weighted (IVW) was used as the primary estimate, the MR pleiotropy residual sum and outlier (MR-PRESSO), the MR-Egger intercept test, and leave-one-out analyses were used to examine the potential horizontal pleiotropy. RESULTS: Genetically proxied DMFS decreases the TH of the banks of the superior temporal sulcus (BANSSTS) with or without global weighted (weighted, ß = - 0.0277 mm, 95% CI: - 0.0470 mm to - 0.0085 mm, P = 0.0047; unweighted, ß = - 0.0311 mm, 95% CI: - 0.0609 mm to - 0.0012 mm, P = 0.0412). The causal associations were robust in various sensitivity analyses. CONCLUSIONS: Dental caries causally decrease the cerebral cortical thickness of the BANKSSTS, a cerebral cortical region crucial for language-related functions, and is the most affected brain region in Alzheimer's disease. This investigation provides the first evidence that dental caries causally affects brain structure, proving the existence of teeth-brain axes. This study also suggested that clinicians should highlight the causal effects of dental caries on brain disorders during the diagnosis and treatments, the cortical thickness of BANKSSTS is a promising diagnostic measurement for dental caries-related brain degeneration.

Advances in protein glycosylation and its role in tissue repair and regeneration.

After tissue damage, a series of molecular and cellular events are initiated to promote tissue repair and regeneration to restore its original structure and function. These events include inter-cell communication, cell proliferation, cell migration, extracellular matrix differentiation, and other critical biological processes. Glycosylation is the crucial conservative and universal post-translational modification in all eukaryotic cells [1], with influential roles in intercellular recognition, regulation, signaling, immune response, cellular transformation, and disease development. Studies have shown that abnormally glycosylation of proteins is a well-recognized feature of cancer cells, and specific glycan structures are considered markers of tumor development. There are many studies on gene expression and regulation during tissue repair and regeneration. Still, there needs to be more knowledge of complex carbohydrates' effects on tissue repair and regeneration, such as glycosylation. Here, we present a review of studies investigating protein glycosylation in the tissue repair and regeneration process.

Observation of macular hole associated with retinoschisis in patients with high myopia.

PURPOSE: To observe the characteristics of highly myopic macular holes (HMMHs) with macular retinoschisis (MRS) by optical coherence tomography (OCT) and explore the possible relationship between HMMHs and different types of MRS. METHODS: We consecutively reviewed the clinical data and OCT images of the patients with HMMHs from June 2015 to February 2021. Then we picked eyes with MRS from these HMMHs for analysis. The minimum linear diameter (MLD), basal diameter (BD), and height (H) of HMMHs were measured. HMMHs were grouped according to the extent or layer involvement of the concomitant MRS and the characteristics were compared among groups. The impact of MRS on the MLD of macular hole was analyzed with multivariable linear regression. RESULTS: We included 127 patients with MRS from 168 HMMHs (75.5%) for analysis. According to the different classification systems, the most frequent type of MRS in HMMHs was S3 (foveal but not entire macular area MRS) (62.2%) and both inner- and outer- (I/O-MRS) involved types. In our study, HMMHs with more extensive MRS had larger MLD, larger BD, larger H, and poorer best-corrected visual acuity (BCVA). Meanwhile, HMMHs with outer layer-involved MRS (outer MRS and I/O-MRS) had larger BD than HMMH with only inner layer-involved MRS. (All P < 0.05) Multivariable linear regression further illustrated only the extent of MRS was significantly associated with the MLD of HMMH, while there was no significant correlation between the involved retinal layers and the MLD of HMMH. CONCLUSION: HMMH with MRS presented as a predominant type in HMMHs. The MRS was always with a relatively large extent and involved both inner and outer layers. MLD of HMMH was mainly affected by the extent of MRS.

A Cadaveric Limb Analysis of the Posterior Tibial Musculotendinous Junction to determine the feasibility of Interosseous Membrane Tendon Transfer.

The transfer of the posterior tibial tendon through the interosseous membrane is potentially an effective treatment to correct the deformity of the foot and ankle. Our study aimed to evaluate the anatomical feasibility of anterior transfer of the posterior tibial tendon through the interosseous membrane route using the musculotendinous junction (MTJ). Eighteen adult cadavers were used. The width and thickness of the tibial posterior MTJ, width of the interosseous membrane at the corresponding level, and the window size of the interosseous membrane were measured. Additionally, the distance between the distal end of the MTJ and the tip of the medial malleolus were recorded. The mean length of the posterior tibial tendon was 83.60 mm, the mean distance of the posterior tibial MTJ to medial malleolus tip was 45.48 mm and the mean length of MTJ was 31.74 mm. The mean width of distal end of MTJ was 7.76 mm, thickness of distal end of MTJ was 4.07 mm and the mean width of the interosseous membrane at the distal end of MTJ was 4.76 mm. We found the mean width of the proximal end of MTJ was 20.68 mm, the mean thickness of proximal end of MTJ was 5.52 mm, and mean width of interosseous membrane at the proximal end of MTJ was 8.76 mm. Our study has demonstrated that a 31 mm length incision made at approximately 45 mm from the proximal end of the medial malleolus can safely reach the MTJ. We recommend an opening length of the interosseous membrane of at least 20 mm.

Becker muscular dystrophy: case report, review of the literature, and analysis of differentially expressed hub genes.

INTRODUCTION: Becker muscular dystrophy (BMD) is a genetic and progressive neuromuscular disease caused by mutations in the dystrophin gene with no available cure. A case report and comprehensive review of BMD cases aim to provide important clues for early diagnosis and implications for clinical practice. Genes and pathways identified from microarray data of muscle samples from patients with BMD help uncover the potential mechanism and provide novel therapeutic targets for dystrophin-deficient muscular dystrophies. METHODS: We describe a BMD family with a 10-year-old boy as the proband and reviewed BMD cases from PubMed. Datasets from the Gene Expression Omnibus database were downloaded and integrated with the online software. RESULTS: The systematic review revealed the clinical manifestations and mutation points of the dystrophin gene. Gene ontology analysis showed that extracellular matrix organization and extracellular structure organization with enrichment of upregulated genes coexist in three datasets. We present the first report of TUBA1A involvement in the development of BMD/Duchenne muscular dystrophy (DMD). DISCUSSION: This study provides important implications for clinical practice, uncovering the potential mechanism of the progress of BMD/DMD, and provided new therapeutic targets.

Thermodynamic Optimization of the Ethylene Oligomerization Chemical Process.

The use of olefin oligomerization in the synthesis of liquid fuel has broad application prospects in military and civil fields. Here, based on finite time thermodynamics (FTT), an ethylene oligomerization chemical process (EOCP) model with a constant temperature heat source outside the heat exchanger and reactor pipes was established. The process was first optimized with the minimum specific entropy generation rate (SEGR) as the optimization objective, then multi-objective optimization was further performed by utilizing the NSGA-II algorithm with the minimization of the entropy generation rate (EGR) and the maximization of the C10H20 yield as the optimization objectives. The results showed that the point of the minimum EGR was the same as that of SEGR in the Pareto optimal frontier. The solution obtained using the Shannon entropy decision method had the lowest deviation index, the C10H20 yield was reduced by 49.46% compared with the point of reference and the EGR and SEGR were reduced by 59.01% and 18.88%, respectively.

Finite-Time Thermodynamic Modeling and Optimization of Short-Chain Hydrocarbon Polymerization-Catalyzed Synthetic Fuel Process.

The short-chain hydrocarbon polymerization-catalyzed synthetic fuel technology has great development potential in the fields of energy storage and renewable energy. Modeling and optimization of a short-chain hydrocarbon polymerization-catalyzed synthetic fuel process involving mixers, compressors, heat exchangers, reactors, and separators are performed through finite-time thermodynamics. Under the given conditions of the heat source temperature of the heat exchanger and the reactor, the optimal performance of the process is solved by taking the mole fraction of components, pressure, and molar flow as the optimization variables, and taking the minimum entropy generation rate (MEGR) of the process as the optimization objective. The results show that the entropy generation rate of the optimized reaction process is reduced by 48.81% compared to the reference process; among them, the component mole fraction is the most obvious optimization variable. The research results have certain theoretical guiding significance for the selection of the operation parameters of the short-chain hydrocarbon polymerization-catalyzed synthetic fuel process.

Repeats in mitochondrial and chloroplast genomes characterize the ecotypes of the Oryza.

Mitochondria and chloroplast are very important organelles for organism, participating in basic life activity. Their genomes contain many repeats which can lead to a variation of genome structure. Oryza is an important genus for human beings' nutrition. Several mitochondrial and chloroplast genomes of Oryza have been sequenced, which help us to insight the distribution and evolution of the repeats in Oryza species. In this paper, we compared six mitochondrial and 13 chloroplast genomes of Oryza and found that the structures of mitochondrial genomes were more diverse than chloroplast genomes. Since repeats can change the structure of the genome, resulting in the structural diversity of the genome, we analyzed all repeats and found 31 repeats in mitochondrial and 13 repeats in chloroplast genomes. Further, we developed 21 pairs of MRS molecular markers and 12 pairs of CRS molecular markers based on mitochondrial repeats and chloroplast repeats, respectively. These molecular markers can be used to detect the repeat-mediated recombination in Oryza mitochondrial and chloroplast genomes by PCR or fluorescence quantification. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-020-01198-6.

Abnormal Fractional Amplitude of Low-Frequency Fluctuation Changes in Patients with Monocular Blindness: A Functional Magnetic Resonance Imaging (MRI) Study.

BACKGROUND We used fractional amplitude of low-frequency fluctuation (fALFF) technology to investigate spontaneous cerebral activity in patients with monocular blindness (MB) and in healthy controls (HCs). MATERIAL AND METHODS Thirty MB patient and 15 HCs were included in this study. All subjects were scanned by resting-state functional magnetic resonance imaging (rs-fMRI). The independent sample t test and chi-squared test were applied to analyze demographics of MB patients and HCs. The 2-sample t test and receiver operating characteristic (ROC) curves were applied to identify the difference in average fALFF values between MB patients and HCs. Pearson's correlation analysis was applied to explore the relationship between the average fALFF values of brain areas and clinical behavior in the MB group. RESULTS MB patients had lower fALFF values in the left anterior cingulate and higher fALFF values in the left precuneus and right and left inferior parietal lobes than in HCs. Moreover, the mean fALFF values of MB patients in the left anterior cingulate had negative correlations with the anxiety scale score (r=-0.825, P<0.001) and the depression scale score (r=-0.871, P<0.001). CONCLUSIONS Our study found that MB patients had abnormal spontaneous activities in the visual and vision-related regions. The finding of abnormal neuronal activity helps to reveal the underlying neuropathologic mechanisms of vision loss.

Altered Brain Network Centrality in Patients with Adult Strabismus with Amblyopia: A Resting-State Functional Magnetic Resonance Imaging (fMRI) Study.

BACKGROUND The aim of this study was to explore potential changes in brain function network activity in patients with adult strabismus with amblyopia (SA) using the voxel-wise degree centrality (DC) method. MATERIAL AND METHODS We enrolled 15 patients with SA (6 males, 9 females) and 15 sex-matched healthy controls (HCs). All subjects completed resting functional magnetic resonance imaging scans. Independent-sample t tests and receiver operating characteristic (ROC) curves were used to assess DC value differences between groups, and Pearson correlation analysis was performed to evaluate correlations between DC-changed brain regions and clinical data of patients with SA. RESULTS Compared with the HC group, DC values that were lower in patients with SA included the left middle frontal gyrus and bilateral angular gyri. Increases were observed in the left fusiform gyrus, right lingual gyrus, right middle occipital gyrus, right postcentral gyrus, and left paracentral lobule. However, DC values were not correlated with clinical manifestations. ROC curve analysis showed high accuracy. CONCLUSIONS We found abnormal neural activity in specific brain regions in patients with SA. Specifically, we observed significant changes in DC values compared to HCs. These changes may be useful to identify the specific mechanisms involved in brain dysfunction in SA.

Colorimetric strategy for ascorbic acid detection based on the oxidase-like activity of silver nanoparticle single-walled carbon nanotube composites.

A colorimetric assay for the determination and quantification of ascorbic acid (AA) is presented using silver nanoparticle (AgNP) single-walled carbon nanotube (AgNP/SWCNT) nanocomposites prepared using a microwave-assisted method. The AgNP/SWCNT nanocomposites possessed oxidase-like properties toward 3,3',5,5'-tetramethylbenzidine (TMB) and could catalyze the oxidation of TMB to form a blue oxidation product (λmax = 652 nm) in the absence of H2 O2 . AA can specifically inhibit the oxidation of TMB, resulting in a decline of the absorbance value and blue colour fading. As such, amounts of AA can be assessed easily by the unaided eye and quantitatively using an ultraviolet-visible light spectrophotometer. Under the optimal reaction conditions, this strategy showed a good linearity ranging from 0.4 µM to 5.0 µM for AA detection, and the limit of detection was 130 nM. This assay was also applied for AA measurement in vitamin C tablets and juice samples that yielded satisfactory results.

Heterocyclic amines in braised chicken may mainly infiltrate from reused marinade during braising, instead of thermic generation.

BACKGROUND: Sauce braised meat products are popular in Asia, although their complicated processing may lead to potential safety risks. Especially, how hazardous compounds are formed during their preparation is still unclear. In the present study, braised chicken breasts, which are a typical Chinese sauce braised meat product, were used to investigate the formation of heterocyclic amines (HCAs) during heat treatment. RESULTS: Precursor content (creatine and reducing sugar), HCA level and temperature were measured in different parts of the chicken breast at each processing stage. The results obtained showed that the increasing trends of total HCA content in different parts of chicken breast were not the same. Only total HCA content in the skin (4.93 ± 0.80 ng g-1 ) increased significantly after deep-frying. During braising, total HCA level in the skin was high (12.1-14.3 ng g-1 ) and relatively stable. However, total HCA content in pectoralis major muscle (3.90-7.40 ng g-1 ) and pectoralis minor muscle (1.44-5.31 ng g-1 ) was much lower than in the skin, and increased steadily with braising time. CONCLUSION: Braising is the main factor which affects HCA level in braised chicken. Combining the results of temperature and precursor content, a possible explanation for the large amount of HCAs in braised chicken is the gradual infiltration from reused marinade, instead of thermic generation. © 2019 Society of Chemical Industry.

Studies of congenital cataract-related TSR1 mutation and its expression in the lens.

Congenital cataract (CC) is a rare disease with dysplasia of the lens, mainly characterized by partial or complete opacity of the lens. The molecular basis of the disease is complex, mutations in over 266 genes associated with congenital cataracts had been reported. In this study, a novel congenital cataract candidate gene TSR1 was identified by whole genome sequencing and Sanger sequencing in a Chinese congenital cataract family. The TSR1 c.202-1G>A substitution affected splicing of TSR1 mRNA was confirmed by a minigene assay. The expression of TSR1 in mouse lens, anterior lens capsule of age-related cataract patients and 24-week human fetal lens were determined by RT-PCR, Western blotting, and immunofluorescence assays. The expression of TSR1 in the embryonic and different developmental stages of the mouse lens was confirmed by analyzing the iSyTE database. The expression of TSR1 was down-regulated in the lens-specific CBP:p300 double knockout mouse, and a set of genes with the same expression pattern of Tsr1 in the CBP:p300 double knockout mouse lens were extracted for protein-protein interaction network analysis, and six proteins were screened for direct interaction with Tsr1. GO function analysis indicated that Tsr1 might play a role in the MAPK-Erk signaling pathway in addition to its involvement in ribosome assembly. This study provided valuable research clues to further clarify the function of Tsr1 in the lens.

Expression of lactate dehydrogenase C correlates with poor prognosis in renal cell carcinoma.

Lactate dehydrogenase C is an isoenzyme of lactate dehydrogenase and a member of the cancer-testis antigens family. In this study, we aimed to investigate the expression and functional role of lactate dehydrogenase C and its basic mechanisms in renal cell carcinoma. First, a total of 133 cases of renal cell carcinoma samples were analysed in a tissue microarray, and Kaplan-Meier survival curve analyses were performed to investigate the correlation between lactate dehydrogenase C expression and renal cell carcinoma progression. Lactate dehydrogenase C protein levels and messenger RNA levels were significantly upregulated in renal cell carcinoma tissues, and the patients with positive lactate dehydrogenase C expression had a shorter progression-free survival, indicating the oncogenic role of lactate dehydrogenase C in renal cell carcinoma. In addition, further cytological experiments demonstrated that lactate dehydrogenase C could prompt renal cell carcinoma cells to produce lactate, and increase metastatic and invasive potential of renal cell carcinoma cells. Furthermore, lactate dehydrogenase C could induce the epithelial-mesenchymal transition process and matrix metalloproteinase-9 expression. In summary, these findings showed lactate dehydrogenase C was associated with poor prognosis in renal cell carcinoma and played a pivotal role in the migration and invasion of renal cell carcinoma cells. Lactate dehydrogenase C may act as a novel biomarker for renal cell carcinoma progression and a potential therapeutic target for the treatment of renal cell carcinoma.

Retroperitoneal laparoscopic partial nephrectomy with segmental renal artery clamping for cancer of the left upper calyx: a case report.

BACKGROUND: Currently, the standard treatment for renal pelvis carcinoma is radical nephroureterectomy with bladder cuff excision. To describe the feasibility of retroperitoneal laparoscopic partial nephrectomy with segmental renal artery clamping for cancer of renal pelvis, we report this special case for the first time. CASE PRESENTATION: A 67-year-old woman received this operation. Preoperative ureteroscopy revealed a papillary neoplasm with a pedicle in the upper calyx of the left kidney. After entering the retroperitoneal space and dissociating the renal artery and renal vein, the target artery was clamped beyond the final bifurcation before entering the parenchyma. After incision of the left renal parenchyma and exposure of the upper calyceal neck, the tumor was found confined to the upper calyx. Thereafter, the renal calyx and parenchyma were sutured successively after complete resection of the neoplasm. Postoperative pathological examination confirmed that the Grade I papillary carcinoma was confined to the mucosal layer. Thus far, there is no evidence of recurrence during the follow-up period for more than 42 months after surgery. CONCLUSIONS: Retroperitoneal laparoscopic partial nephrectomy with segmental renal artery clamping of the kidney provides a feasible treatment modality for noninvasive tumors that are limited to the calyx.