Purpose To examine the clinicopathologic,immunohistochemical,and molecular genetic characteristics and differential diagnosis of low-grade oncocytic tumor(LOT)of kidney with CK7 positive and CD117 negative,so as to enhance the understanding of this tumor among pathologists.Methods A total of five cases of renal LOT from the First Affiliated Hospi-tal of Soochow University between December 2016 and February 2023 were included in this analysis.The clinicopathological fea-tures,immunophenotype,genetic characteristics,and prognosis were evaluated using HE staing,immunohistochemical staining,and Sanger sequencing.Additionally,relevant literature was re-viewed to supplement the findings.Results Among the cohort of five patients,four were female and one was male,aged 57-70 years with a median age of 65 years and an average age of 64.8 years.Clinical presentation revealed that only the first case exhibited frequent urination accompanied by intermittent lumba-go,while the remaining cases were asymptomatic and incidental-ly discovered.Imaging studies demonstrated space-occupying le-sions with clear boundaries and even internal echoes on B-ultra-sonography,and patchy low-density shadows in the center with obvious edge enhancement on CT.Grossly,the tumor was nodu-lar,with a maximum diameter ranging from 2.1 to 7.6 cm,and an average diameter of 4.04 cm,with a solid section.Micro-scopically,the boundary of LOT was consistently well-defined,with a thick capsule.The arrangement of tumor cells was ob-served to be both dense and sparse,accompanied by fresh bleed-ing foci and proteinoid secretions.Focal lymphocyte aggrega-tion,hepatic plate like and hepatic sinusoid like structures,thick-walled blood vessels,false nodules of tumor cells,and old hemorrhage were also noted.The tumor cells exhibited uniformi-ty in shape,appearing round or polygonal,with eosinophilic and fine granular cytoplasm.The nuclei were of similar size and shape,appearing round or oval with a clear nuclear membrane.The histological features of the tumor included 2-grade small nu-cleoli,perinuclear halos,binuclear cells,and nuclear shrink-age,but no mitotic figures were detected.The immunophenotyp-ic analysis revealed strongly diffuse expression of CK7 in the tumor cells,while CD117 was negative.The Ki67 proliferation index was low.Sanger sequencing identified mutations in mTORC1 pathway genes in four cases,including three mutations in MTOR and one mutation in RHEB.The patients underwent either local or radical nephrectomy,and were followed up for a period ranging from 2 to 52 months,during which all patients re-mained free of recurrence.Conclusion The low-grade,eosino-philic,and rare renal tumor known as LOT exhibits inert behav-ior.At present,the follow-up results show that complete resec-tion of local operation is sufficient,and the prognosis is good.It is important to distinguish this lesion from other eosinophilic re-nal tumors.

Animals ; Embryonic Stem Cells ; diagnostic imaging ; metabolism ; Humans ; Mice, Inbred C57BL ; Parthenogenesis ; Telomere ; diagnostic imaging ; metabolism ; Transcriptome ; Ultrasonography

Homotypic fusion and vacuole protein sorting(HOPS) is a protein complex consisting of VPS11, VPS16, VPS18, VPS33, VPS39, VPS41 and regulates membrane transport in vivo through membrane fusion mechanisms. The evidence suggests that HOPS complex as a fusion factor, facilitates autophagosome-lysosome fusion. To determine whether the HOPS complex directly interacts with the autophagic SNARE protein STX17 in vitro, the coding sequence of the six genes were amplified from the existing plasmids by PCR, and then ligated to the prokaryotic expression vector pGEX 4T-1-GST or pET-His-NusA. After identification through colony PCR and DNA sequencing, 6 recombinant plasmids were constructed and transferred into Escherichia coli BL21 (DE3). The recombinant proteins were purified by glutathione sepharose 4B and nickel column. We used the tobacco etch virus protease to cut off the GST-tag or His-NusA-tag, to obtain HA-VPS11 protein of about 105 kDa, Flag-VPS16 protein of about 97 kDa, HA-VPS18 protein of about 108 kDa, Flag-VPS33 protein of about 70 kDa, HA-VPS39 protein of about 97 kDa, and Flag-VPS41 protein of about 98 kDa. The function of the purified proteins was verified by in vitro glutathione S-transferases pull-down assay, confirming that autophagic SNARE protein STX17 interacted directly with HOPS components. Our findings provide experimental basis to further study the function and mechanism of HOPS complex in the process of autophagosome-lysosome fusion.

Animals ; Embryonic Stem Cells ; metabolism ; Histone Deacetylase 6 ; deficiency ; genetics ; metabolism ; Mice ; Reproduction ; genetics