Viral protein R(Vpr) plays an important role in the replication and pathogenesis of Human immunodeficiency virus type 1(HIV-1). Some of the various functions attributed to Vpr, including the induction of G2/M cell cyc...Viral protein R(Vpr) plays an important role in the replication and pathogenesis of Human immunodeficiency virus type 1(HIV-1). Some of the various functions attributed to Vpr, including the induction of G2/M cell cycle arrest, activating the NF-κB pathway, and promoting viral reverse transcription, might be interrelated. To test this hypothesis, a panel of Vpr mutants were investigated for their ability to induce G2/M arrest and to activate the NF-κB pathway. The results showed that the Vpr mutants that failed to activate NF-κB also lost the activity to induce G2/M arrest, which suggests that inducing G2/M arrest via Vpr depends at least partially on the activation of NF-κB. This latter possibility is supported by data showing that knocking down the key factors in the NF-κB pathway – p65, Rel B, IKKα, or IKKβ– partially rescued the G2/M arrest induced by Vpr.Our results suggest that the NF-κB pathway is probably involved in Vpr-induced G2/M cell cycle arrest.展开更多
Conjunctival melanoma(CM) is a rare and fatal malignant eye tumor. In this study, we deciphered a novel anti-CM mechanism of a natural tetracyclic compound named as cucurbitacin B(CuB). We found that CuB remarkably in...Conjunctival melanoma(CM) is a rare and fatal malignant eye tumor. In this study, we deciphered a novel anti-CM mechanism of a natural tetracyclic compound named as cucurbitacin B(CuB). We found that CuB remarkably inhibited the proliferation of CM cells including CM-AS16,CRMM1, CRMM2 and CM2005.1, without toxicity to normal cells. CuB can also induce CM cells G2/M cell cycle arrest. RNA-seq screening identified KIF20A, a key downstream effector of FOXM1 pathway, was abolished by CuB treatment. Further target identification by activity-based protein profiling chemoproteomic approach revealed that GRP78 is a potential target of CuB. Several lines of evidence demonstrated that CuB interacted with GRP78 and bound with a Kdvalue of0.11 μmol/L. Furthermore, ATPase activity evaluation showed that CuB suppressed GRP78 both in human recombinant GRP78 protein and cellular lysates. Knockdown of the GRP78 gene significantly induced the downregulation of FOXM1 and related pathway proteins including KIF20A, underlying an interesting therapeutic perspective. Finally, CuB significantly inhibited tumor progression in NCG mice without causing obvious side effects in vivo. Taken together, our current work proved that GRP78-FOXM1-KIF20A as a promising pathway for CM therapy, and the traditional medicine CuB as a candidate drug to hinder this pathway.展开更多
基金supported by grants from the Chinese Ministry of Health (2012ZX10001006)the National Natural Science Foundation of China (81271812 and 31370182)+1 种基金111 Project (B08011)the Postgraduate Scholarship Program of the China Scholarship Council
文摘Viral protein R(Vpr) plays an important role in the replication and pathogenesis of Human immunodeficiency virus type 1(HIV-1). Some of the various functions attributed to Vpr, including the induction of G2/M cell cycle arrest, activating the NF-κB pathway, and promoting viral reverse transcription, might be interrelated. To test this hypothesis, a panel of Vpr mutants were investigated for their ability to induce G2/M arrest and to activate the NF-κB pathway. The results showed that the Vpr mutants that failed to activate NF-κB also lost the activity to induce G2/M arrest, which suggests that inducing G2/M arrest via Vpr depends at least partially on the activation of NF-κB. This latter possibility is supported by data showing that knocking down the key factors in the NF-κB pathway – p65, Rel B, IKKα, or IKKβ– partially rescued the G2/M arrest induced by Vpr.Our results suggest that the NF-κB pathway is probably involved in Vpr-induced G2/M cell cycle arrest.
基金supported by the National Mega-project for Innovative Drugs of China(2019ZX09721001-004-003)the National Natural Science Foundation of China(82003603 and 81872747)+1 种基金the Innovative Research Team of High-level Local Universities in Shanghai,the National Special Fund for State Key Laboratory of Bioreactor Engineering(2060204,China)Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism(2021 Sci&Tech 03-28,China).
文摘Conjunctival melanoma(CM) is a rare and fatal malignant eye tumor. In this study, we deciphered a novel anti-CM mechanism of a natural tetracyclic compound named as cucurbitacin B(CuB). We found that CuB remarkably inhibited the proliferation of CM cells including CM-AS16,CRMM1, CRMM2 and CM2005.1, without toxicity to normal cells. CuB can also induce CM cells G2/M cell cycle arrest. RNA-seq screening identified KIF20A, a key downstream effector of FOXM1 pathway, was abolished by CuB treatment. Further target identification by activity-based protein profiling chemoproteomic approach revealed that GRP78 is a potential target of CuB. Several lines of evidence demonstrated that CuB interacted with GRP78 and bound with a Kdvalue of0.11 μmol/L. Furthermore, ATPase activity evaluation showed that CuB suppressed GRP78 both in human recombinant GRP78 protein and cellular lysates. Knockdown of the GRP78 gene significantly induced the downregulation of FOXM1 and related pathway proteins including KIF20A, underlying an interesting therapeutic perspective. Finally, CuB significantly inhibited tumor progression in NCG mice without causing obvious side effects in vivo. Taken together, our current work proved that GRP78-FOXM1-KIF20A as a promising pathway for CM therapy, and the traditional medicine CuB as a candidate drug to hinder this pathway.
