1
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Zhang D, He C, Guo Y, Li J, Li B, Zhao Y, Yu L, Chang Z, Pei H, Yang M, Li N, Zhang Q, He Y, Pan Y, Zhao ZJ, Zhang C, Chen Y. Efficacy of SCF drug conjugate targeting c-KIT in gastrointestinal stromal tumor. BMC Med 2022; 20:257. [PMID: 35999600 PMCID: PMC9400206 DOI: 10.1186/s12916-022-02465-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 07/05/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Gastrointestinal stromal tumor (GIST) is a rare type of cancer that occurs in the gastrointestinal tract. The majority of GIST cases carry oncogenic forms of KIT, the receptor for stem cell factor (SCF). Small molecule kinase inhibitor imatinib is effective in prolonging the survival of GIST patients by targeting KIT. However, drug resistance often develops during the therapeutic treatment. Here, we produced a SCF-emtansine drug conjugate (SCF-DM1) with favorable drug efficacy towards GIST cells. METHODS Recombinant human SCF (rhSCF) was expressed in E. coli cells and further purified with Ni-NTA Sepharose and Phenyl Sepharose. It was then conjugated with DM1, and the conjugated product SCF-DM1 was evaluated using in vitro cell-based assays and in vivo xenograft mouse model. RESULTS SCF-DM1 was effective in inhibiting imatinib-sensitive and -resistant GIST cell lines and primary tumor cells, with IC50 values of < 30 nM. It induced apoptosis and cell cycle arrest in GIST cells. In xenograft mouse model, SCF-DM1 showed favorable efficacy and safety profiles. CONCLUSIONS rhSCF is a convenient and effective vector for drug delivery to KIT positive GIST cells. SCF-DM1 is an effective drug candidate to treat imatinib-sensitive and -resistant GIST.
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Affiliation(s)
- Dengyang Zhang
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Chunxiao He
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Yao Guo
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Jianfeng Li
- Digestive Diseases Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Bo Li
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Yuming Zhao
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Liuting Yu
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Zhiguang Chang
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Hanzhong Pei
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Ming Yang
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Na Li
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Qi Zhang
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Yulong He
- Digestive Diseases Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Yihang Pan
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China
| | - Zhizhuang Joe Zhao
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
| | - Changhua Zhang
- Digestive Diseases Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China.
| | - Yun Chen
- Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, Guangdong, China.
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3
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Batisson I, Der Vartanian M, Gaillard-Martinie B, Contrepois M. Full capacity of recombinant Escherichia coli heat-stable enterotoxin fusion proteins for extracellular secretion, antigenicity, disulfide bond formation, and activity. Infect Immun 2000; 68:4064-74. [PMID: 10858223 PMCID: PMC101696 DOI: 10.1128/iai.68.7.4064-4074.2000] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have successfully used the major subunit ClpG of Escherichia coli CS31A fimbriae as an antigenic and immunogenic exposure-delivery vector for various heterologous peptides varying in nature and length. However, the ability of ClpG as a carrier to maintain in vitro and in vivo the native biological properties of passenger peptide has not yet been reported. To address this possibility, we genetically fused peptides containing all or part of the E. coli human heat-stable enterotoxin (STh) sequence to the amino or carboxyl ends of ClpG. Using antibodies to the ClpG and STh portions for detecting the hybrids; AMS (4-acetamido-4'-maleimidylstilbene-2, 2'-disulfonate), a potent free thiol-trapping reagent, for determining the redox state of STh in the fusion; and the suckling mouse assay for enterotoxicity, we demonstrated that all ClpG-STh proteins were secreted in vitro and in vivo outside the E. coli cells in a heat-stable active oxidized (disulfide-bonded) form. Indeed, in contrast to many earlier studies, blocking the natural NH(2) or COOH extremities of STh had, in all cases, no drastic effect on cell release and toxin activity. Only antigenicity of STh C-terminally extended with ClpG was strongly affected in a conformation-dependent manner. These results suggest that the STh activity was not altered by the chimeric structure, and therefore that, like the natural toxin, STh in the fusion had a spatial structure flexible enough to be compatible with secretion and enterotoxicity (folding and STh receptor recognition). Our study also indicates that disulfide bonds were essential for enterotoxicity but not for release, that spontaneous oxidation by molecular oxygen occurred in vitro in the medium, and that the E. coli cell-bound toxin activity in vivo resulted from an effective export processing of hybrids and not cell lysis. None of the ClpG-STh subunits formed hybrid CS31A-STh fimbriae at the cell surface of E. coli, and a strong decrease in the toxin activity was observed in the absence of CS31A helper proteins. In fact, chimeras translocated across the outer membrane as a free folded monomer once they were guided into the periplasm by the ClpG leader peptide through the CS31A-dependent secretory pathway. In summary, ClpG appears highly attractive as a carrier reporter protein for basic and applied research through the engineering of E. coli for culture supernatant delivery of an active cysteine-containing protein, such as the heat-stable enterotoxin.
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Affiliation(s)
- I Batisson
- Laboratoire de Microbiologie, Institut National de la Recherche Agronomique, Centre de Recherches de Clermont-Ferrand-Theix, 63122 Saint-Genès-Champanelle, France
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4
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Skvirsky RC, Reginald S, Shen X. Topology analysis of the colicin V export protein CvaA in Escherichia coli. J Bacteriol 1995; 177:6153-9. [PMID: 7592380 PMCID: PMC177455 DOI: 10.1128/jb.177.21.6153-6159.1995] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The antibacterial protein toxin colicin V is secreted from Escherichia coli cells by a dedicated export system that is a member of the multicomponent ATP-binding cassette (ABC) transporter family. At least three proteins, CvaA, CvaB, and TolC, are required for secretion via this signal sequence-independent pathway. In this study, the subcellular location and transmembrane organization of membrane fusion protein CvaA were investigated. First, a series of CvaA-alkaline phosphatase (AP) protein fusions was constructed. Inner and outer membrane fractionations of cells bearing these fusions indicated that CvaA is inner membrane associated. To localize the fusion junctions, the relative activities of the fusion proteins, i.e., the amounts of phosphatase activity normalized to the rate of synthesis of each protein, as well as the stability of each fusion, were determined. These results indicated that all of the fusion junctions occur on the same side of the inner membrane. In addition, the relative activities were compared with that of native AP, and the protease accessibility of the AP moieties in spheroplasts and whole cells was analyzed. The results of these experiments suggested that the fusion junctions occur within periplasmic regions of CvA. We conclude that CvaA is an inner membrane protein with a single transmembrane domain near its N terminus; the large C-terminal region extends into the periplasm. This study demonstrates the application of AP fusion analysis to elucidate the topology of a membrane-associated protein having only a single transmembrane domain.
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Affiliation(s)
- R C Skvirsky
- Department of Biology, University of Massachusetts-Boston 02125, USA
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5
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Sanchez J, Solorzano RM, Holmgren J. Extracellular secretion of STa heat-stable enterotoxin by Escherichia coli after fusion to a heterologous leader peptide. FEBS Lett 1993; 330:265-9. [PMID: 8375497 DOI: 10.1016/0014-5793(93)80885-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The mature 19-amino acid STa heat-stable enterotoxin of E. coli has a preceding peptide of 53 amino acids which contains two domains called Pre (aa 1-19) and Pro (aa 20-53) sequences, proposed to be essential for extracellular toxin release by this host. The Pro sequence, however, has been proven not be indispensable for this process since Pro deletion mutants secrete STa. To find out if Pre and/or other unremoved natural STa flanking sequences are responsible for toxin secretion in those mutants we genetically fused mature STa directly to the leader peptide of the periplasmic E. coli heat-labile enterotoxin B-subunit (LTB). Expression of this gene fusion resulted in extracellular secretion of biologically active STa by E. coli independently of natural STa neighboring genetic sequences. Moreover, these results suggest that STa might be able to gain access to the extracellular milieu simply upon its entry into the E. coli periplasm once guided into this compartment by the LTB leader peptide. To test if extracellular secretion in this fashion might be extended to other disulfide bond-rich small peptides, the 13 amino acid conotoxin GI and a non-enterotoxic STa-related decapeptide were cloned. None of the two peptides was found in culture supernatants, in spite of high structural homology to the toxin. Failure to be secreted most likely leads to degradation as peptides were also not detected in bacterial sonicates. We hypothesize that cysteine-rich peptides must have an amino acid length and/or number of disulfide bridges closer to those in STa for them to follow this toxin secretory pathway in E. coli.
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Affiliation(s)
- J Sanchez
- Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico
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6
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Yang Y, Gao Z, Guzmán-Verduzco LM, Tachias K, Kupersztoch YM. Secretion of the STA3 heat-stable enterotoxin of Escherichia coli: extracellular delivery of Pro-STA is accomplished by either Pro or STA. Mol Microbiol 1992; 6:3521-9. [PMID: 1474896 DOI: 10.1111/j.1365-2958.1992.tb01787.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The methanol-soluble, heat-stable enterotoxin of Escherichia coli is a protease-resistant extracellular peptide which is synthesized as a 72-amino-acid precursor Pre-Pro-STA3. The specific roles of Pre (19 amino acids), Pro (34 amino acids) and STA3 (19 amino acids) in the secretion process were studied by functionally deleting each of the three domains. Deletion of the Pre signal sequence resulted in a short-lived cell-associated molecule with an M(r) equivalent to that of Pro-STA3. Deletion of Pro (i.e., Pre-STA3) resulted in the rapid extracellular accumulation of STA3; the periplasmic intermediate found in the secretion of the wild-type toxin was undetected. Deletion of the STA3 domain resulted in a cell-associated Pre-Pro peptide; with time this form converted to periplasmic Pro which later became extracellular. When DNA encoding either STA3, by itself, or Pro-STA3 (lacking the signal peptide) was expressed, these peptides were degraded intracellularly, with no periplasmic or extracellular forms detected. The results presented demonstrate that the signal peptide (Pre) is essential even for the export of small peptides to the periplasm, and that its absence causes the STA3 domain to become susceptible to intracellular proteases. The rapid degradation of intracellular STA3 indicates that its proteolytic resistance is acquired in a compartment other than the cytoplasm. The results also show that after the Pre domain is proteolytically cleaved from Pre-STA3 and Pre-Pro, the STA3 and Pro peptides can exit to the culture supernatant.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- Y Yang
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
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Abstract
We have identified a gene involved in bacterial cell division, located immediately upstream of the
ftsI
gene in the min 2 region of the
Escherichia coli
chromosome. This gene, which we named
ftsL
, was detected through characterization of Tn
phoA
insertions in a plasmid containing this chromosomal region. Tn
phoA
topological analysis and fractionation of alkaline phosphatase fusion proteins indicated that the
ftsL
gene product is a 13.6-kDa cytoplasmic membrane protein with a cytoplasmic amino terminus, a single membrane-spanning segment, and a periplasmic carboxy terminus. The
ftsL
gene is essential for cell growth and division. A null mutation in
ftsL
resulted in inhibition of cell division, formation of long, nonseptate filaments, ultimate cessation of growth, and lysis. Under certain growth conditions, depletion of FtsL or expression of the largest
ftsL-phoA
fusion produced a variety of cell morphologies, including Y-shaped bacteria, indicating a possible general weakening of the cell wall. The FtsL protein is estimated to be present at about 20 to 40 copies per cell. The periplasmic domain of the protein displays a sequence with features characteristic of leucine zippers, which are involved in protein dimerization.
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10
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Delor I, Kaeckenbeeck A, Wauters G, Cornelis GR. Nucleotide sequence of yst, the Yersinia enterocolitica gene encoding the heat-stable enterotoxin, and prevalence of the gene among pathogenic and nonpathogenic yersiniae. Infect Immun 1990; 58:2983-8. [PMID: 2201642 PMCID: PMC313599 DOI: 10.1128/iai.58.9.2983-2988.1990] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The gene encoding the heat-stable enterotoxin (yst) was cloned from the chromosome of Yersinia enterocolitica W1024 (serotype O:9), and the nucleotide sequence was determined. The yst gene encodes a 71-amino-acid polypeptide. The C-terminal 30 amino acids of the predicted protein exactly correspond to the amino acid sequence of the toxin extracted from culture supernatants (T. Takao, N. Tominaga, and Y. Shimonishi, Biochem. Biophys. Res. Commun. 125:845-851, 1984). The N-terminal 18 amino acids have the properties of a signal sequence. The central 22 residues are removed during or after the secretion process. This organization in three domains (Pre, Pro, and mature Yst) resembles that of the enterotoxin STa of Escherichia coli. The degree of conservation between the E. coli and Y. enterocolitica toxins is much lower in the Pre and the Pro domains than in the mature proteins. The mature toxin of Y. enterocolitica is much larger than that of E. coli, but the active domain appears to be highly conserved. The yst gene of Y. enterocolitica introduced in E. coli K-12 directed the secretion of an active toxin. The cloned yst gene was used as an epidemiological probe among a collection of 174 strains representative of all Yersinia species except Yersinia pestis and numerous Y. enterocolitica subgroups. In Y. enterocolitica, there was a clear-cut difference between pathogenic and nonpathogenic strains: 89 of 89 pathogenic and none of 51 nonpathogenic strains contained yst-homologous DNA, suggesting that Yst is involved in pathogenesis. Among the other Yersinia species, only four strains of Yersinia kristensenii had DNA homologous to yst.
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Affiliation(s)
- I Delor
- Unité de Microbiologie, Université Catholique de Louvain, Brussels, Belgium
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12
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Rasheed JK, Guzmán-Verduzco LM, Kupersztoch YM. Two precursors of the heat-stable enterotoxin of Escherichia coli: evidence of extracellular processing. Mol Microbiol 1990; 4:265-73. [PMID: 2187146 DOI: 10.1111/j.1365-2958.1990.tb00593.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Expression of the gene of the methanol-soluble, heat-stable enterotoxin of Escherichia coli (STA) allowed the identification by SDS-PAGE of a cell-associated 7500 Dalton STA-related peptide; when similar experiments were performed with a phosphate buffer SDS-PAGE system, an additional Mr 9800 band became apparent. The 9800 Dalton form, pre-pro-STA, accumulated as an intracellular species when the experiments were performed in the presence of the proton ionophore CCCP (carbonylcyanide m-chlorophenylhydrazone); by pulse-chase experiments, it was shown that pre-pro-STA became a periplasmic Mr 7500 pro-STA and this form was chased to the culture supernatant; periplasmic and extracellular pro-STA showed the same electrophoretic mobility. A short time after the pulse, pro-STA was converted extracellularly to mature STA (Mr 4500). It is proposed that STA is synthesized as pre-pro-STA, a 72-amino-acid peptide that is subsequently cleaved between amino acids 19 and 20 as it is translocated across the inner membrane. The resulting 53-amino-acid pro-STA is first detected in the periplasm and is then secreted to the culture supernatant. Pro-STA is cleaved extracellularly to yield mature STA (Mr 4500).
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Affiliation(s)
- J K Rasheed
- Department of Microbiology, University of Texas, Southwestern Medical Center, Dallas 75235
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