Functional Interactions of Fibronectin and TNFα: A Paradigm of Physiological Linkage Between Cytokines and Extracellular Matrix Moieties

The ECM is composed of various cell-adhesive glycoproteins, such as, fibronectin (FN), laminin (LN), and different types of glycosaminoglycans and proteoglycans. These building blocks of the ECM are linked together to form a dense and complex tissue that fills the interstitial spaces and comprises the boundaries between cells and tissues. The ECM is the major milieu in which immune cells function during inflammatory processes (Shimizu and Shaw, 1991; Yamada, 1991). Recognition of ECM-glycoproteins by immune cells is mediated by very late activation (VLA) receptors, also referred to as integrins of the β₁-subfamily (Hynes, 1992). A prerequisite of lymphocyte-ECM interactions is activation of the cells by mitogens, or via their CD3-T cell receptor complex, either of these types of activation modulates the affinity of otherwise inactive β₁-integrins (Shimizu, et al., 1990).     

稳定表达人源GABAAR-CHO细胞株的建立

目的: 构建α₁亚基诱导表达、β₂和γ_2L亚基稳定表达的人源α₁β₂γ_2L-GABA_AR-CHO(Chinese hamster ovary)细胞株。方法: 从人cDNA文库中扩增α₁、β₂、γ_2L亚基编码基因,分别构建亚基表达载体;将三个亚基表达载体共转染CHO-K1细胞,通过抗性筛选、膜电位检测法进行稳定表达克隆筛选;通过qPCR、Western blot对亚基表达进行鉴定;以激动剂GABA、阳性变构调节剂地西泮(diazepam,Dia)、拮抗剂荷包牡丹碱(bicuculine)为工具药,采用全细胞膜片钳方法及膜电位检测法对稳定表达细胞的药理学功能进行鉴定。结果: 经克隆筛选获得表达量较高的α₁β₂γ_2L-GABA_AR-CHO并对其亚基表达鉴定,结果显示该细胞稳定表达α₁、β₂、γ_2L亚基,构建的α₁β₂γ_2L-GABA_AR-CHO细胞仅在加入四环素(tetracyclin)诱导的情况下表达α₁亚基并与β₂、γ_2L组装成具有功能活性的α₁β₂γ_2L-GABA_AR;对其进行全细胞膜片钳检测研究发现,GABA可对其产生激动效应,引起α₁β₂γ_2L-GABA_AR-CHO细胞产生氯离子通道特征性电流变化,Dia可剂量依赖性地增强GABA对α₁β₂γ_2L-GABA_AR的激动效应;在膜电位检测研究中,获得GABA激动效应EC₅₀为(177.72 ± 15.92)nmol/L,Dia变构效应EC₅₀为(3.63±0.52)μmol/L,拮抗剂Bicuculine拮抗效应IC₅₀为(538.83±29.55)nmol/L。结论: 通过采用诱导表达策略,成功构建了α₁β₂γ_2L-GABA_AR-CHO稳定表达细胞株,该细胞株具有对激动剂、阳性变构剂、拮抗剂特异性检测的药理学功能。     

PKA-mediated phosphorylation of the beta1-adrenergic receptor promotes Gs/Gi switching

Recently, it has been shown that PKA-mediated phosphorylation of the β₂-adrenergic receptor (β₂-AR) by the cyclic AMP-dependent protein kinase (PKA) reduces its affinity for G_s and increases its affinity for G_i. Here we demonstrate that, like the β₂-AR, the β₁-AR is also capable of “switching” its coupling from G_s to G_i in a PKA-dependent manner. The β₁-AR is capable of activating adenylate cyclase via G_s, and can also activate the extracellular-regulated kinases, p44 and p42 (ERK1/2). In transfected CHO cells, the observed β₁-AR-mediated activation of ERK is both sensitive to pertussis toxin (PTX), indicating involvement of G_i/G_o, and to the PKA inhibitor, H-89. β₁-ARs with PKA phosphorylation sites mutated to alanines are unable to activate ERK. Mutating these same residues to aspartic acid, mimicking PKA phosphorylation, leads to a decrease in G_s-stimulated cAMP accumulation and an increase in PTX-sensitive ERK activation. These results strongly support the hypothesis that the β₁-AR, like the β₂-AR, can undergo PKA-dependent “G_s/G_i switching”.     

Tryptophan fluorescence quenching by alkaline pH and ternary complex formation in human beta 1 beta 1 and horse EE alcohol dehydrogenases.

The horse EE and human β₁β₁ alcohol dehydrogenase isoenzymes have almost identical protein backbone folding patterns and contain 2 tryptophans per subunit (Trp-15 and Trp-314). Tyr-286, which had been proposed to quench the fluorescence of Trp-314 by resonance energy transfer at alkaline pH in EE, is substituted by Cys in β₁β₁. The proposed role of Tyr-286 in pH-dependent quenching of EE is confirmed by our observation that tryptophan fluorescence of β₁β₁ is not substantially quenched at alkaline pH. Tyr-286 had also been implicated in the quenching of Trp-314 upon formation of the EE-NAD⁺-trifluoroethanol ternary complex. However, β₁β₁ exhibits the same extent of tryptophan fluorescence quenching as EE upon complexation, which strongly suggests that Tyr-286 is not involved in ternary complex quenching.     

Reactivity study of cyclopentadienyl osmium(II) bisphosphine azido complexes with activated alkynes and nitriles: Isolation of osmium triazolato and tetrazolato complexes by 1,3-dipolar addition

The cyclopentadienyl osmium(II) complexes [(η⁵-C₅H₅)Os(PPh₃)₂X] [X = Br (1), CH₃CN (2)] reacts with sodium azide (NaN₃) to yield the corresponding azido complex [(η⁵-C₅H₅)Os(PPh₃)₂N₃] (3). This undergoes [3+2] dipolar cycloaddition reaction with activated alkynes like dimethyl and diethyl acetylenedicarboxylate to yield triazolato complexes [(η⁵-C₅H₅)Os(PPh₃)₂{N₃C₂(CO₂R)₂}] [R = –CH₂CH₃ (4) and –CH₃ (5)]. The complex 3 also reacts with nitriles such as tetracyanoethylene (TCE), fumaronitrile and p-nitrobenzonitrile to yield complexes of the type [(η⁵-C₅H₅)Os(PPh₃)₂{N₄C₂(CN)C(CN)₂}] (6), [(η⁵-C₅H₅)Os(PPh₃)₂{N₃C₂HCN}] (7) and [(η⁵-C₅H₅)Os(PPh₃)₂{N₄C(C₆H₄–p-NO₂)}] (8). These complexes were fully characterized on the basis of microanalyses, FT-IR and NMR spectroscopic data. The molecular structure of the representative complex [(η⁵-C₅H₅)Os(PPh₃)₂{N₃C₂(CO₂CH₂CH₃)₂}] (4) was determined by single crystal X-ray analysis.     

Beta2-adrenoceptor agonists induce the mammalian clock gene, hPer1, mRNA in cultured human bronchial epithelium cells in vitro

The mammalian Per1 gene is one of the most important components of circadian clock function of the suprachiasmatic nucleus and peripheral tissues. We examined whether the β₂-adrenoceptor agonists, procaterol and fenoterol, induce human Per1 mRNA expression in human bronchial epithelium. The in vitro stimulation of β₂-adrenoceptor agonists in BEAS-2B cells led to a remarkable increase in the level of hPer1 mRNA. Moreover, fenoterol or procaterol induced the phosphorylation of CREB in BEAS-2B cells as verified by immunoblot analysis. β₂-adrenoceptor agonists induced human Per1 mRNA expression by the signaling pathways of cAMP-CREB in BEAS-2B cells.     

Hetero-polynuclear complexes containing bridging diphenylphosphino-alkenes and -alkynes. The crystal structure of an Rh2{μ−ν:ν−P(Ph2) (CH2)3C≡CR}Co2 complex

The phosphinoalkenes Ph₂P(CH₂)_nCH=CH₂ (n= 1, 2, 3) and phosphinoalkynes Ph₂P(CH₂)_n C≡CR (R = H, N = 2, 3; R = CH₃, N = 1) have been prepared and reacted with the dirhodium complex (η−C₅H₅)₂Rh₂(μ−CO) (μ−η²−CF₃C₂CF₃). Six new complexes of the type (ν−C₅H₅)₂(Rh₂(CO) (μ−η¹:η¹−CF₃C₂CF₃)L, where L is a P-coordinated phosphinoalkene, or phosphinoalkyne have been isolated and fully characterized; the carbonyl and phosphine ligands are predominantly trans on the Rh---Rh bond, but there is spectroscopic evidence that a small amount of the cis-isomer is formed also. Treatment of the dirhodium-phosphinoalkene complexes with (η−CH₃C₅H₄)Mn(CO)₂thf resulted in coordination of the manganese to the alkene function. The Rh₂---Mn complex [(η−C₅H₅)₂Rh₂(CO) (μ−η¹:η¹−CF₃C₂CF₃) {Ph₂P(CH₂)₃CH=CH₂} (η−CH₃C₅H₄)Mn(CO)₂] was fully characterized. Simi treatment of the dirhodium-phosphinoalkyne complexes with Co₂(CO)₈ resulted in the coordination of Co₂(CO)₆ to the alkyne function. The Rh₂---Co₂ complex [(η−C₅H₅)₂Rh₂(CO) (μ−η¹:η¹−CF₃C₂CF₃) {Ph₂PCH₂C≡CCH₃}Co₂(CO)₂], C₃₇H₂₅Co₂F₆O₇PRh₂, was fully characteriz spectroscopically, and the molecular structure of this complex was determined by a single crystal X-ray diffraction study. It is triclinic, space group (C_i¹, No. 2) with a = 18.454(6), B = 11.418(3), C = 10.124(3) Å, = 112.16(2), β = 102.34(3), γ = 91.62(3)°, Z = 2. Conventional R on |F| was 0.052 fo observed (I > 3σ(I)) reflections. The Rh₂ and Co₂ parts of the molecule are distinct, the carbonyl and phosphine are mutually trans on the Rh---Rh bond, and the orientations of the alkynes are parallel for Rh₂ and perpendicular for Co₂. Attempts to induce Rh₂Co₂ cluster formation were unsuccessful.     

Heterobimetallic aggregates of copper(I) with thiotungstates and thiomolybdates. Synthesis and characterization of polymeric (NEt4)3[Cu4(NCS)5WS4], (NEt4)2[(CuNCS)3WS4] and (NEt4)2[(CuNCS)4WS4], M = Mo, W

Reaction of (NEt₄)₂MS₄ (M = Mo, W) with CuCl and KSCN (or NH₄SCN) in acetone or acetonitrile affords a new set of mixed metal–sulfur compounds: infinite anionic chains Cu₄(NCS)₅MS_4³⁻ (1,2), (CuNCS)₃WS_4²⁻ (3) and two dimensional polymeric dianions (CuNCS)₄MS_4²⁻ (4,5). Crystal of 1 (M = W) and 3 are triclinic, space group P1(1:a = 10.356(2),b = 15.039(1),c = 17.356(2)Å, = 78.27(1)°, β = 88.89(2)° and γ = 88.60(1)°,Z = 2,R = 0.04 for 3915 independent data;3:a = 8.449(2),b = 14.622(4),c = 15.809(8)Å, = 61.84(3)°, β = 73.67(3)° and γ = 78.23(2)°,Z = 2,R = 0.029 for 6585 independent data). Crystals of 4 (M = W) and 5 (M = Mo) are monoclinic, space group P2₁/m,Z = 2 (4:a = 12.296(4),b = 14.794(4),c = 10.260(3)Åand β = 101.88(3)°,R = 0.034 for 4450 independent data;5:a = 12.306(2),b = 14.809(3),c = 10.257(2)Åand β = 101.99(3)°,R = 0.043 for 3078 independent data). The crystal structure determinations of 4 and 5 show that four edges of the tetrahedral MS_4²⁻ core are coordinated by copper atoms forming WS₄Cu₄ aggregates linked by eight-membered Cu(NCS)₂Cu rings. A two-dimensional network is thus formed in the diagonal (101) plane. The space between the anionic two-dimensional networks is filled with the NEt_4⁺ cations. Additional NCS groups lead to the [Cu₄(NCS)₅WS₄]³⁻ (1) trianion connected by NCS bridges forming pseudo-dimers. These latter are held together by weak CuS(NCS) interactions giving rise to infinite chains along a direction parallel to [100]. In contrast complex3 develops infinite chains from WS₄Cu₃ aggregates with the same Cu(NCS)₂Cu bridges as in 4 and 5. These chains are running along a direction parallel to [010]. The structural data of the different types of polymeric compounds containing MS_4²⁻ and CuNCS have been used to interpret vibrational spectroscopic data of the thiocyanate groups.     

Beta(3)-adrenoceptor agonists for the treatment of frequent urination and urinary incontinence: 2-[4-(2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl)phenoxy]-2-methylpropionic acid.

In a search for novel analogues of β₃-adrenoceptor (AR) agonists relaxing the bladder for treatment of urinary dysfunction, 2-[4-(2-{[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino}ethyl)phenoxy]-2-methylpropionic acids (1a–e), into which a fibrate-like structure had been incorporated, were synthesised. Compound 1a was found to be a selective β₃-AR agonist in functional assays using the ferret detrusor (β₃-AR), rat uterus (β₂-AR), and rat atrium (β₁-AR); β₃: EC₅₀=7.8 nM, β₂: IC₅₀=7,300 nM, β₁: EC₂₀=23,000 nM. The introduction of a chlorine atom or methyl substituent at the ortho-position on the phenyl ring of 1a further improved β₃-AR selectivity. In an in vivo study, 1a lowered intrabladder pressure (ED₅₀=31 μg/kg) in rats, without increasing heart rate, in keeping with the in vitro results. Consequently, it is proposed that 1a and its analogues (1b–e), possess β₃-AR agonistic activity in the absence of undesirable β₁- or β₂-AR mediated actions, and may be useful for clinical treatment and pharmacological studies.     

π-Arene complexes.: Part 12. Synthesis of chromiumtricarbonyl complexes of quinoline and N-methylindoles and selected metallation reactions

The lithiation of indole, using a slight excess of n-butyl lithium in THF, followed by methylation and reaction with [Cr(CO)₆] in refluxing dibutyl ether, resulted in the formation of [Cr(η⁶-N-methylindole)(CO)₃] (1a) and [Cr(η⁶-N-methyl-2-methylindole)(CO)₃] (1b). In contrast, lithiation of quinoline in THF, silylation and the subsequent reaction with [Cr(CO)₆] under similar reaction conditions, afforded [Cr(η⁶-N-trimethylsilyl-2-butyl-1,2-dihydroquinoline)(CO)₃] (2) and [Cr(η⁶-{2-butyl-1,2,3,4-tetrahydroquinoline})(CO)₃] (3). The formation of [Cr(η⁶-2,2′-bis{N-methylindolyl})(CO)₃] (4) implied lithiation at the 2-position of 1a. However, metallation at the 7-position was also indicated during the same reaction. In the presence of [Mn(CO)₅Br], product 4 and the transmetallation product [Cr(η⁶-{7-(N-methylindolyl)Mn(CO)₅})(CO)₃] (5) were isolated. Reaction with titanocene dichloride gave [Cr(η⁶-{2-(N-methylindolyl)TiCp₂Cl})(CO)₃] (6), which slowly converted into [TiCp₂{Cr(η⁶-2-(N-methylindolyl)(CO)₃}₂] (7).     

Reactivity of {(Ph3P)Pt[μ-η-H---SiH(Ar)]}2 (Ar=2-isopropyl-6-methylphenyl) with phosphines. X-ray crystal structure of trans-{(dppe)Pt[μ-SiH(Ar)]}2

The dinuclear Pt---Si complex {(Ph₃P)Pt{μ-η²-H---SiH(IMP)]}₂ (trans-1a–cis-1b=3:1; IMP=2-isopropyl-6-methylphenyl) reacted with basic phosphines such as 1,2-bis(diphenylphosphino)ethane (dppe) and dimethylphenylphosphine (PMe₂Ph) to afford different dinuclear Pt---Si complexes with loss of H₂, {(P)₂Pt[μ-SiH(IMP)]}₂ [P=dppe, trans-2a (major), cis-2b (trace); PMe₂Ph, 3 (trans only)]. Complexes 2 and 3 were characterized by multinuclear NMR spectroscopy and X-ray crystallography (2a). In contrast, the reaction of 1a,b with the sterically demanding tricyclohexylphosphine (PCy₃) afforded {(Cy₃P)Pt{μ-η²-H---SiH(IMP)]}₂ (trans-4a–cis-4b 2:1) analogous to 1a,b where the central Pt₂Si₂(μ-H)₂ core remains intact but the PPh₃ ligands have been replaced by PCy₃. Complexes 4a and 4b was characterized by multinuclear NMR and IR spectroscopies.     

The synthesis and reactions of A-ring aromatic steroid complexes of manganese tricarbonyl

Treatment of the A-ring aromatic steroids estrone 3-methyl ether and β-estradiol 3, 17-dimethyl ether with Mn(CO)₅⁺BF₄⁻ in CH₂Cl₂ yields the corresponding [(steroid)Mn(CO)₃]BF₄ salts 1 and 2 as mixtures of and β isomers. The X-ray structure of [(estrone 3-methyl ether)Mn(CO)₃]BF₄ · CH₂Cl₂ (1) having the Mn(CO)₃ moiety on the side of the steroid is reported: space group P2₁ with a=10.3958(9), b=10.9020(6), c=12.6848(9) Å, β=111.857(6)°, Z=2, V=1334.3(2) ų, _calc=.481 cm⁻³, R=0.0508, and wR=0.0635. The molecule has the traditional ‘piano stool’ structure with a planar arene ring and linear Mn---C---O linkages. The nucleophiles NaBH₄ and LiCH₂C(O)CMe₃ add to [(β-estradiol 3,17-dimethyl ether)Mn(CO)₃]BF₄ (2) in high yield to give the corresponding - and β-cyclohexadienyl manganese tricarbonyl complexes (3). The nucleophiles add meta to the arene -OMe substituent and exo to the metal. The and β isomers of 3 were separated by fractional crystallization and the X-ray structure of the β isomer with an exo-CH₂C(O)CMe₃ substituent is reported (complex 4): space group P2₁2₁2₁ with a=7.5154(8), b=15.160(2), c=25.230(3) Å, Z=4, V=2874.4(5) ų, _calc=1.244 g cm⁻³, R=0.0529 and wR2=0.1176. The molecule 4 has a planar set of dienyl carbon atoms with the saturated C(1) carbon being 0.592 Å out of the plane away from the metal. The results suggest that the manganese-mediated functionalization of aromatic steroids is a viable synthetic procedure with a range of nucleophiles of varying strengths.     

Amyloid beta peptide (25-35) activates protein kinase C leading to cyclooxygenase-2 induction and prostaglandin E2 release in primary midbrain astrocytes

Prostaglandins (PGs) are generated by the enzymatic activity of cyclooxygenase-1 and -2 (COX-1/2) and modulate several functions in the CNS such as the generation of fever, the sleep/wake cycle, and the perception of pain. Moreover, the induction of COX-2 and the generation of PGs has been linked to neuroinflammatory aspects of Alzheimer's disease (AD). Non-steroidal anti-inflammatory drugs (NSAIDs) that block COX enzymatic activity have been shown to reduce the incidence of AD in various epidemiological studies. While several reports investigated the expression of COX-2 in neurons and microglia, expression of COX-2 in astroglial cells has not been investigated in detail. Here we show that amyloid β peptide 25–35 (Aβ_25–35) induces COX-2 mRNA and protein synthesis and a subsequent release of prostaglandin E₂ (PGE₂) in primary midbrain astrocytes. We further demonstrate that protein kinase C (PKC) is involved in Aβ_25–35-induced COX-2/PGE₂ synthesis. PKC-inhibitors prevent Aβ_25–35-induced COX-2 and PGE₂ synthesis. Furthermore Aβ_25–35 rapidly induces the phosphorylation and enzymatic activation of PKC in primary rat midbrain glial cells and in primary human astrocytes from post mortem tissue. Our data suggest that the PKC isoforms and/or β are most probably involved in Aβ_25–35-induced expression of COX-2 in midbrain astrocytes. The potential role of astroglial cells in the phagocytosis of amyloid and the involvement of PGs in this process suggests that a modulation of PGs synthesis may be a putative target in the prevention of amyloid deposition.     

Cis- and trans-titanium complexes with doubly silyl-bridged dicyclopentadienyl ligands: molecular structure of [(TiCl)2(μ-O){(SiMe2)2(η-C5H3)2}]2(μ-O)2

The reaction of TiCl₄ with Li₂[(SiMe₂)₂(η⁵-C₅H₃)₂] in toluene at room temperature afforded a mixture of cis- and trans-[(TiCl₃)₂{(SiMe₂)₂(η⁵-C₅H₃)₂}] in a molar ratio of 1/2 after recrystallization. The complex trans-[(TiCl₃)₂{(SiMe₂)₂(η⁵-C₅H₃)₂}] was hydrolyzed immediately by the addition of water to THF solutions to give trans-[(TiCl₂)₂(μ-O){(SiMe₂)₂(η⁵-C₅H₃)₂}] as a solid insoluble in all organic solvents, whereas hydrolysis of cis-[(TiCl₃)₂{(SiMe₂)₂(η⁵-C₅H₃)₂}] under different conditions led to the dinuclear μ-oxo complex cis-[(TiCl₂)₂)(μ-O){(SiMe₂)₂(η⁵-C₅H₃)₂}] and two oxo complexes of the same stoichiometry [(TiCl)₂(μ-O){(SiMe₂)₂(η⁵-C₅H₃)₂}]₂(μ-O)₂ as crystalline solids. Alkylation of cis- and trans-[(TiCl₃)₂{(SiMe₂)₂(η⁵-C₅H₃)₂}] with MgCIMe led respectively to the partially alkylated cis-[(TiMe₂Cl)₂{(SiMe₂)₂(η⁵-C₅H₃)₂}] and the totally alkylated trans-[(TiMe₃)₂{(SiMe₂)₂(η⁵-C₅H₃)₂}] compounds. The crystal and molecular structure of the tetranuclear oxo complex [(TiCl)₂(μ-O){(SiMe₂)₂(η⁵-C₅H₃)₂}]₂(μ-O)₂ was determined by X-ray diffraction.     

Synthesis, structure, and heterogeneous catalytic activity of tungsten chalcogenide cubane cluster containing alkaline earth metal complex

A new compound containing a cubane tungsten chalcogenide cluster [W₄(μ₃-Te)₄(CN)₁₂]⁶⁻ and Ca²⁺ complex units has been prepared by the reaction of aqueous solution of K₆[W₄(μ₃-Te)₄(CN)₁₂] · 5H₂O with the solution of a Ca(NO₃)₂ and phen(1,10-phenanthroline) (1:2 molar ratio) in a solvent mixture of H₂O/EtOH. The structure of [{Ca(phen)₂(H₂O)}{Ca(phen)(H₂O)₄}{Ca(phen)₂(H₂O)₃}][W₄Te₄(CN)₁₂] · 5H₂O 1 has been determined by X-ray crystallography. Compound 1 contains [{Ca(phen)(H₂O)₄}{Ca(phen)₂(H₂O)₃}][W₄(μ₃- Te)₄(CN)₁₂] units bridged by {Ca(phen)₂(H₂O)}²⁺ units to form an one-dimensional zigzag chain structure. Interestingly, compound 1 showed a heterogeneous catalytic activity in the transesterification of a range of esters with methanol under the mild conditions. Moreover, it can be reused without any loss of activity through 10 runs with ester.     

Slippage of η-allenyl/propargyl to an η structure and tautomerization of η-propargyl to η-allenyl in ligand addition and substitution reactions of platinum(II) complexes

Reactions of [(PPh₃)₂Pt(η³-CH₂CCPh)]OTf with each of PMe₃, CO and Br⁻ result in the addition of these species to the metal and a change in hapticity of the η³-CH₂CCPh to η¹-CH₂CCPh or η¹-C(Ph)=C=CH₂. Thus, PMe₃ affords [(PMe₃)₃Pt(η¹-C(Ph)=C=CH₂)]⁺, CO gives both [trans-(PPh₃)₂Pt(CO)(η¹-CH₂CCPh)]⁺ and [trans-(PPh₃)₂Pt(CO)(η¹-C(Ph)=C=CH₂)]⁺, and LiBr yields cis-(PPh₃)₂PtBr(η¹-CH₂CCPh), which undergoes isomerization to trans-(PPh₃)₂PtBr(η¹-CH₂CCPh). Substitution reactions of cis- and trans-(PPh₃)₂PtBr(η¹-CH₂CCPh) each lead to tautomerization of η¹-CH₂CCPh to η¹-C(Ph)=C=CH₂, with trans-(PPh₃)₂PtBr(η¹-CH₂CCPh) affording [(PMe₃)₃Pt(η¹-C(Ph)=C=CH₂)]⁺ at ambient temperature and the slower reacting cis isomer giving [trans-(PPh₃)(PMe₃)₂Pt(η¹-C(Ph)=C=CH₂)]⁺ at 54 °C . All new complexes were characterized by a combination of elemental analysis, FAB mas spectrometry and IR and NMR (¹H, ¹³C{¹H} and ³¹P{¹H}) spectroscopy. The structure of [(PMe₃)₃Pt(η¹-C(Ph)=C=CH₂)]BPh₄·0.5MeOH was determined by single-crystal X-ray diffraction analysis.     

Anti-β1 Integrin IgG Inhibits Pulmonary Macrometastasis and the Size of Micrometastases from a Murine Mammary Carcinoma

In the present report, we investigated the possible importance of β₁ integrins in the growth and metastasis of a murine mammary carcinoma, SP1, and a metastatic variant, SP1-3M in vivo. CBA/J female mice bearing SP1 tumor transplants were injected with anti-β₁ integrin IgG or control nonimmune IgG (200 μg per mouse; i.p.) every two days. Animals received anti-CD4 antibody (100 μg per mouse) at time zero to suppress immunity against rabbit IgG. Outgrowth of macroscopic metastases from SP1, but not from SP1-3M primary tumors, was markedly inhibited in animals receiving anti-β₁ integrin IgG but not nonimmune IgG. To assess the stage(s) in the metastatic cascade affected, we examined the number and diameter of micrometastatic nodules in treated and untreated groups. The diameter of micrometastases was significantly reduced in SP1-tumor-bearing mice treated with anti-β₁ integrin IgG compared to control IgG, although the number of nodules per cm² of lung sections examined remained unchanged. No change in the number or size of micrometastases in SP1-3M tumor-bearing mice was observed. No difference in the binding, or complement-mediated and antibody-dependent cell-mediated cytotoxicity of anti-β₁ integrin IgG with SP1 and SP1-3M cells was detected. The results suggest that under these conditions anti-β₁ integrin inhibits metastatic tumor growth in lung tissue, but has minimal effect on intravasation, adhesion to target organs and extravasation.