Steady-state and time-resolved fluorescence studies on wild type and mutant chromatium vinosum high potential iron proteins: holo- and apo-forms

Detailed circular dichroism (CD), steady-state and time-resolved tryptophan fluorescence studies on the holo- and apo- forms of high potential iron protein (HiPIP) from Chromatium vinosum and its mutant protein have been carried out to investigate conformational properties of the protein. CD studies showed that the protein does not have any significant secondary structure elements in the holo- or apo- HiPIP, indicating that the metal cluster does not have any effect on formation of secondary structure in the protein. Steady-state fluorescence quenching studies however, suggested that removal of the iron-sulfur ([Fe(4)S(4)](3+)) cluster from the protein leads to an increase in the solvent accessibility of tryptophans, indicating change in the tertiary structure of the protein. CD studies on the holo- and apo- HiPIP also showed that removal of the metal prosthetic group drastically affects the tertiary structure of the protein. Time-resolved fluorescence decay of the wild type protein was fitted to a four-exponentials model and that of the W80N mutant was fitted to a three-exponentials model. The time-resolved fluorescence decay was also analyzed by maximum entropy method (MEM). The results of the MEM analysis agreed with those obtained from discrete exponentials model analysis. Studies on the wild type and mutants helped to assign the fast picosecond lifetime component to the W80 residue, which exhibits fast fluorescence energy transfer to the [Fe(4)S(4)](3+) cluster of the protein. Decay-associated fluorescence spectra of each tryptophan residues were calculated from the time-resolved fluorescence results at different emission wavelengths. The results suggested that W80 is in the hydrophobic core of the protein, but W60 and W76 are partially or completely exposed to the solvent.

The anti-apoptotic role of interleukin-6 in human cervical cancer is mediated by up-regulation of Mcl-1 through a PI 3-K/Akt pathway

Interleukin-6 (IL-6), a multifunctional cytokine, has recently been implicated in human cervical cancer, though the mechanism remains elusive. This study demonstrates that the anti-apoptotic protein Mcl-1 and IL-6 was concomitantly expressed in human cervical cancer tissues and cell lines, but not in normal cervix tissues. Upon IL-6 treatment, Mcl-1, but not other Bcl-2 family members, was rapidly up-regulated peaking at 4-8 h in human cervical cancer C33A cells. Supporting this observation, using anti-IL-6 or anti-IL-6 receptor antibody to interrupt the IL-6 autocrine loop in SiHa cells significantly reduced cellular level of Mcl-1. This study hypothesizes that the expression of Mcl-1 in cervical cancer cells is regulated by IL-6. The matter of which signaling pathways transduced by IL-6 is responsible for the Mcl-1 up-regulation is further investigated herein. Blocking the STAT3 or MAPK pathway with dominant-negative mutant STAT3F or the MEK inhibitor PD98059 failed to inhibit IL-6-mediated Mcl-1 expression. Meanwhile, the IL-6-induced Mcl-1 up-regulation was effectively abolished by treatment with PI 3-K inhibitors, LY294002. Additionally, overexpression of dominant-negative (dn) Akt in C33A cells could inhibit the IL-6-induced increase of Mcl-1. Finally, overexpression of IL-6 in C33A cells caused a markable resistance to apoptosis induced by doxorubicin or cisplatin. Transient transfection of IL-6-overexpressed cells with a mcl-1 antisense vector, leading to the attenuation of their apoptosis-resistant activity. In conclusion, the data herein suggest that IL-6 regulated the mcl-1 expression via a PI 3-K/Akt-dependent pathway that may facilitate the oncogenesis of human cervical cancer by modulating the apoptosis threshold.

Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions

Curcumin (diferuloylmethane), a yellow substance from the root of the plant Curcuma longa Linn., has been demonstrated to inhibit carcinogenesis of murine skin, stomach, intestine and liver. However, the toxicology, pharmacokinetics and biologically effective dose of curcumin in humans have not been reported. This prospective phase-I study evaluated these issues of curcumin in patients with one of the following five high-risk conditions: 1) recently resected urinary bladder cancer; 2) arsenic Bowen's disease of the skin; 3) uterine cervical intraepithelial neoplasm (CIN); 4) oral leucoplakia; and 5) intestinal metaplasia of the stomach. Curcumin was taken orally for 3 months. Biopsy of the lesion sites was done immediately before and 3 months after starting curcumin treament. The starting dose was 500 mg/day. If no toxicity > or = grade II was noted in at least 3 successive patients, the dose was then escalated to another level in the order of 1,000, 2,000, 4,000, 8,000, and 12,000 mg/day. The concentration of curcumin in serum and urine was determined by high pressure liquid chromatography (HPLC). A total of 25 patients were enrolled in this study. There was no treatment-related toxicity up to 8,000 mg/day. Beyond 8,000 mg/day, the bulky volume of the drug was unacceptable to the patients. The serum concentration of curcumin usually peaked at 1 to 2 hours after oral intake of crucumin and gradually declined within 12 hours. The average peak serum concentrations after taking 4,000 mg, 6,000 mg and 8,000 mg of curcumin were 0.51 +/- 0.11 microM, 0.63 +/- 0.06 microM and 1.77 +/- 1.87 microM, respectively. Urinary excretion of curcumin was undetectable. One of 4 patients with CIN and 1 of 7 patients with oral leucoplakia proceeded to develop frank malignancies in spite of curcumin treatment. In contrast, histologic improvement of precancerous lesions was seen in 1 out of 2 patients with recently resected bladder cancer, 2 out of 7 patients of oral leucoplakia, 1 out of 6 patients of intestinal metaplasia of the stomach, I out of 4 patients with CIN and 2 out of 6 patients with Bowen's disease. In conclusion, this study demonstrated that curcumin is not toxic to humans up to 8,000 mg/day when taken by mouth for 3 months. Our results also suggest a biologic effect of curcumin in the chemoprevention of cancer.

Interleukin-6 in cervical cancer: the relationship with vascular endothelial growth factor

OBJECTIVE

Interleukin-6 (IL-6), a central proinflammatory cytokine, has been implicated in cervical cancer, though its role remains elusive. This study was an attempt to elucidate the role of IL-6 in the pathogenesis of cervical cancer, with particular emphasis on tumor angiogenesis.

METHODS

Cytosolic IL-6, vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF) levels were determined via enzyme immunoassay in 60 FIGO stage IB-IIA cervical cancer patients. Immunohistochemical staining in tissue sections was performed to analyze the distributions of IL-6 and IL-6 receptors. Meanwhile, human papillomavirus (HPV) DNA was detected by polymerase chain reaction-based survey. In vitro studies of two cervical cancer cell lines, C33A and SiHa, for the interaction between IL-6 and VEGF were also performed.

RESULTS

Consistently higher expression of IL-6 and VEGF was evident in cancerous tissues than in adjacent noncancer tissues in early-stage cervical cancer patients (P < 0.01). After recombinant human IL-6 was added, VEGF was induced in a time- and dose-dependent manner in cervical cancer cell line C33A. Correspondingly, interrupting the IL-6 autocrine machinery with either anti-IL-6 or anti-IL-6 receptor antibody markedly reduced the expression of VEGF at the transcriptional level in SiHa cells. Significantly higher levels of IL-6 in cancer tissues were observed in patients older than 45 (P < 0.01), patients with tumors >2 cm (P < 0.01), patients with oncogenic HPV-16 or -18 infections (P < 0.01), and patients with squamous cell carcinoma (P = 0.02). Patients with a deeper stromal invasion, vaginal invasion, lymphovascular emboli, or lymph node metastasis appeared to have higher intratumoral IL-6 levels, although the differences were statistically insignificant.

CONCLUSIONS

Substantially high microenvironmental IL-6 levels promote tumor angiogenesis and the development of cervical cancer. Thus, inhibition of the biological activity of IL-6 may be potentially beneficial.

Polymorphisms of GA/GT microsatellite loci from Anguilla japonica

Six novel microsatellite loci, containing (GA)(15\N17) or (GT)(10\N19) perfect tandem repeats, were isolated and characterized for the catadromous eel Anguilla japonica. The allelic size of the 6 loci ranged from 79 to 226 bp in length. All loci were polymorphic with a mean number of 14.7 alleles per locus and a mean heterozygosity of 0.67, suggesting higher polymorphism than that of freshwater and anadromous fishes, but lower than that of marine fishes. Genotype diversity of the 6 loci ranged from 0.22 to 0.61 with a mean value of approximately 0.5. Cross-species amplification showed that 5 of the 6 microsatellite primers proved to be useful in addressing questions of population genetics for all Anguilla species.

Regulation of G proteins by covalent modification

Heterotrimeric G protein alpha,beta, and gamma subunits are subject to several kinds of co- and post-translational covalent modifications. Among those relevant to G protein-coupled receptor signaling in normal cell function are lipid modifications and phosphorylation. N-myristoylation is a co-translational modification occurring for members of the G(i) family of Galpha subunits, while palmitoylation is a post-translational modification that occurs for these and most other Galpha subunits. One or both modifications are required for plasma membrane targeting and contribute to regulating strength of interaction with the Gbetagamma heterodimer, effectors, and regulators of G protein signaling (RGS proteins). Galpha subunits, including those with transforming activity, are often inactive when unable to be modified with lipids. The reversible nature of palmitoylation is intriguing in this regard, as it lends itself to a regulation integrated with the activation state of the G protein. Several Galpha subunits are substrates for phosphorylation by protein kinase C and at least one is a substrate for phosphorylation by the p21-activated protein kinase. Phosphorylation in both instances inhibits the interactions of these subunits with the Gbetagamma heterodimer and RGS proteins. Several Galpha subunits are also substrates for tyrosine phosphorylation. A Ggamma subunit is phosphorylated by protein kinase C, with the consequence that it interacts more tightly with a Galpha subunit but less well with an effector.

Cytosol vascular endothelial growth factor in endometrial carcinoma: correlation with disease-free survival

OBJECTIVE

The aim of this study was to evaluate whether vascular endothelial growth factor (VEGF) could be a marker for disease-free survival in endometrial carcinoma patients.

METHODS

Fifty-three patients with endometrial carcinoma undergoing surgery were enrolled. Clinical and pathologic items were recorded. Cytosol VEGF was quantified by enzyme immunoassay. The microvessel density (MVD) of the excised tumors was immunohistochemically assessed. The relationship among MVD, cytosol VEGF concentration of the tumor tissues, and clinicopathologic parameters was analyzed. The risk factors influencing clinical outcome were tested.

RESULTS

Higher cytosol VEGF concentrations and MVD values were noted in tumors with advanced stage (more than stage I) (917 versus 125 pg/mg, P = 0.03; 94.1 +/- 37.8 versus 60.8 +/- 38.9, P = 0.008), lymphovascular emboli (917 versus 102 pg/mg, P = 0.001; 94.4 +/- 33.2 versus 62.4 +/- 40.7, P = 0.009), and lymph node metastasis (1032 versus 95 pg/mg, P < 0.001; 116.5 +/- 30.8 versus 56.7 +/- 33.3, P < 0.001). The cytosol VEGF and MVD showed a positive linear correlation (VEGF versus MVD, r = 0.41, P = 0.003). Grade 3 tumor and overexpressed cytosol VEGF (> 800 pg/mg) are independent risk factors for recurrence. There was a trend that patients with grade 1 or 2 tumors and normal-expressed VEGF had the highest probability of disease-free survival, and patients with grade 3 tumors and overexpressed cytosol VEGF had the poorest probability of disease-free survival.

CONCLUSIONS

Cytosol VEGF had a good correlation with the disease progression and metastasis in endometrial carcinoma, and it might also be an independent prognostic factor for disease-free survival of endometrial carcinoma patients.

Carcinosarcoma of ovary associated with previous radiotherapy

Carcinosarcoma is a rare neoplasm which, in the female genital tract, arises mainly in the endometrium. Although the pathogenesis remains obscure, there is an apparent association between pelvic irradiation and uterine sarcomas. There have been sporadic case reports of the development of carcinosarcomas of the cervix, vagina, and extragenital areas, but not of the ovary, after previous pelvic irradiation. We describe a case of ovarian carcinosarcoma arising in a 74-year-old female who had pelvic irradiation 33 years previously. Exploratory laparotomy showed a 25 x 18 x 9 cm left ovarian tumor with adjacent organ invasion including peri-uterine serosa and rectum. The patient was treated by optimal cytoreduction, followed by chemotherapy with adriamycin and cisplatin. However, acute hepatitis caused by reactivation of hepatitis B virus infection developed just before the fifth course of chemotherapy. She died of hepatic failure two weeks later.

Vascular endothelial growth factor and prognosis of cervical carcinoma

OBJECTIVE

To evaluate vascular endothelial growth factor (VEGF) as a marker for predicting lymph node metastasis and an independent prognostic factor of early-stage cervical carcinoma.

METHODS

One hundred thirty-five women with stage IB-IIA cervical carcinoma had radical abdominal hysterectomies and pelvic lymph node dissections. Intratumoral cytosol VEGF concentrations were assayed with enzyme immunoassay. Histopathologic items and cytosol VEGF-influencing clinical outcomes were compared.

RESULTS

Twenty-two women (16.3%) who had disease recurrence had higher levels of cytosol VEGF (1020 versus 112 pg/mg protein, P <.001) than those without recurrence. Using a cutoff value of 400 pg/mg protein resulted in best sensitivity of 75%, best specificity of 70%, positive predictive value of 41%, and negative predictive value of 92%. Only overexpressed cytosol VEGF (hazard ratio 6.44, P <.001) was an independent prognostic factor of disease-free survival. The overexpressed cytosol VEGF (hazard ratio 4.50, P =.021) and positive lymphovascular emboli (hazard ratio 4.11, P =.045) were independent prognostic factor of overall survival.

CONCLUSION

Cytosol VEGF might be a biomarker for the status of pelvic lymph nodes in early-stage cervical carcinoma and an independent prognostic indicator of its outcome.

Strategies for amplification by polymerase chain reaction of the complete sequence of the gene encoding nuclear large subunit ribosomal RNA in corals

The nearly complete nuclear large subunit ribosomal RNA (LSU rRNA) gene in corals was amplified by primers designed from polymerase chain reaction (PCR) strategies. The motif of the putative 3'-terminus of the LSU rRNA gene was sequenced and identified from intergenic spacer (IGS) clones obtained by PCR using universal primers designed for corals. The 3'-end primer was constructed in tandem with the universal 5'-end primer for the LSU rRNA gene. PCR fragments of 3500 bp were amplified for octocorals and non- Acropora scleractinian corals. More than 80% of the Acropora LSU rRNA gene (3000 bp) was successfully amplified by modification of the 5'-end of the IGS primer. Analysis of the 5'-end of LSU rDNA sequences, including the D1 and D2 divergent domains, indicates that the evolutionary rate of the LSU rDNA differs among these taxonomic groups of corals. The genus Acropora showed the highest divergence pattern in the LSU rRNA gene, and the presence of a long branch of the Acropora clade from the other scleractinian corals in the phylogenetic tree indicates that the evolutionary rate of Acropora LSU rDNA might have accelerated after divergence from the common ancestor of scleractinian corals.

Angiogenesis of endometrial carcinomas assessed by measurement of intratumoral blood flow, microvessel density, and vascular endothelial growth factor levels

OBJECTIVE

To evaluate the relationship between blood flow in the tumor assessed by color Doppler ultrasound, microvessel density, and vascular endothelial growth factor levels in endometrial carcinoma.

METHODS

Forty-nine patients undergoing surgery for endometrial carcinoma were enrolled. Transvaginal color Doppler ultrasound was performed preoperatively and the lowest resistance index (RI) in the tumor was recorded for analysis. Vascular endothelial growth factor in the tumor was quantified by enzyme immunoassay. The microvessel density of the excised tumor was assessed immunohistochemically. The relationships between the corresponding RI, microvessel density, and vascular endothelial growth factor level of the tumor tissues and clinical and pathologic parameters were analyzed.

RESULTS

Significantly lower RIs were noted in tumors of stage II or greater (0.37 compared with 0.50, P <.001), of high histologic grade (grade 3) (0.34 compared with 0.49, P =.004), with deep myometrial invasion (one-half depth or greater) (0.39 compared with 0.49, P =.002), with lymphovascular emboli (0.38 compared with 0.49, P <.001), or with lymph node metastasis (0.30 compared with 0.49, P <.001) compared with stage I tumors and tumors of histologic grade 1 or 2, with superficial myometrial invasion, without lymphovascular emboli, or with no lymph node metastasis. Increased vascular endothelial growth factor levels and microvessel density (x200 field) also were detected in tumors of stage II or greater (975 compared with 129 pg/mg, P =.014; and 88 compared with 61, P =.018, respectively), with lymphovascular emboli (1138 compared with 120 pg/mg, P =.002; and 86 compared with 63, P =.023), or with lymph node metastasis (1011 compared with 95 pg/mg, P <.001; and 98 compared with 61, P =. 019). Resistance index, microvessel density, and vascular endothelial growth factor levels in the tumor showed linear correlations (RI compared with microvessel density: r = -.32, P =. 03; RI compared with vascular endothelial growth factor levels: r = -.40, P =.004; microvessel density compared with vascular endothelial growth factor levels: r =.36, P =.011).

CONCLUSION

Blood flow assessed by color Doppler ultrasound has histologic and biologic correlations with angiogenesis and vascular endothelial growth factor levels and might play an important role in predicting tumor progression and metastasis in endometrial carcinoma.

Altering expression of alpha3beta1 integrin on podocytes of human and rats with diabetes

The adhesion molecule integrin alpha3beta1 is the major receptor of podocyte to the glomerular capillary basement membrane (GBM). Since progressive alteration of the glomerular extracellular matrix (ECM) compartment leading to GBM thickening is common in diabetic nephropathy, we investigated the cellular distribution of alpha3beta1 integrin in podocytes of patients with diabetic nephropathy and streptozotocin-induced diabetic rats, and we evaluated the effects of high glucose on the cultured rat podocytes. Both human and rat kidneys were stained using the immunoelectron microscopy and immunoperoxidase technique with mouse monoclonal antibodies to human integrin alpha3 subunit. The results showed that both the number of immunogold particles and the staining of integrin alpha3 subunit on podocytes were weaker in patients with diabetic nephropathy than those of control kidneys. The staining of alpha3 on podocytes in the poorly-controlled diabetic rats was also weaker after one and three months of hyperglycemia. However, the staining was identical to controls in rats with only one week of hyperglycemia. High glucose (25 mM) but not streptozotocin in vitro suppressed the alpha3 expression of cultured rat podocytes. Our results demonstrated that the expression of integrin alpha3beta1 on podocytes was suppressed in both human and rats with diabetes, possibly due to the effects of hyperglycemia, and the suppression became more severe with the duration of diabetes.

Regulation of galpha i palmitoylation by activation of the 5-hydroxytryptamine-1A receptor

Nearly all alpha subunits of heterotrimeric GTP-binding regulatory proteins (G proteins) are palmitoylated at cysteine residues near the N terminus. A regulated cycle of palmitoylation could provide a mechanism for modulating G protein signaling by affecting protein interactions and localization of the subunit. In the present studies we utilized both [(3)H]palmitate incorporation and pulse-chase techniques to address the dynamics of alpha(i) palmitoylation in Chinese hamster ovary cells. Both techniques demonstrated a dose- and time-dependent change in [(3)H]palmitate labeling of alpha(i) upon activation of stably expressed 5-hydroxytryptamine-1A receptors by the agonist (+/-)-2-dipropylamino-8-hydroxy-1,2,3, 4-tetrahydronaphthalene hydrobromide (DPAT), with an EC(50) of approximately 10 nm. For the incorporation assay, DPAT elicited an approximate doubling in labeling at the earliest time point measured. For the pulse-chase assay, DPAT promoted a significant loss of radiolabel almost equally as fast. These data demonstrate that the exchange of palmitate on alpha(i) is increased upon stimulation of 5-hydroxytryptamine-1A receptors through the combined processes of depalmitoylation and palmitoylation. These results provide the basis for extending the concept of regulated exchange of palmitate beyond G(s) and provide a framework for exploring the specific functional attributes of the palmitoylated and depalmitoylated forms of subunit.

Laparoscopic cystectomy of a twisted, benign, ovarian teratoma in the first trimester of pregnancy

Adnexal torsion is an unusual, but serious complication in pregnancy. The treatment is surgical, but this may increase the risk of pregnancy loss in the first trimester. The use of laparoscopic surgery, which is less invasive than traditional laparotomy, has been limited by diagnostic and technical difficulties including determination of ovarian tumor nature and spillage of cyst contents intraoperatively. A 25-year-old woman in her 11th week of pregnancy had acute severe left lower-abdominal pain, which was diagnosed as left ovarian teratoma with torsion. She underwent emergency laparoscopic surgery with unwinding of the twisted fallopian tube and ovary and cystectomy of the teratoma. The patient subsequently delivered a full-term baby, without complications. Accurate ultrasound and cytologic diagnoses along with copious intraoperative warm, normal saline irrigation were likely contributing factors to the successful outcome of this case.

Neural and local effects of hypoxia on cardiovascular responses to obstructive apnea

Obstructive sleep apnea (OSA) acutely increases systemic (Psa) and pulmonary (Ppa) arterial pressures and decreases ventricular stroke volume (SV). In this study, we used a canine model of OSA (n = 6) to examine the role of hypoxia and the autonomic nervous system (ANS) in mediating these cardiovascular responses. Hyperoxia (40% oxygen) completely blocked any increase in Ppa in response to obstructive apnea but only attenuated the increase in Psa. In contrast, after blockade of the ANS (20 mg/kg iv hexamethonium), obstructive apnea produced a decrease in Psa (-5.9 mmHg; P < 0.05) but no change in Ppa, and the fall in SV was abolished. Both the fall in Psa and the rise in Ppa that persisted after ANS blockade were abolished when apneas were induced during hyperoxia. We conclude that 1) hypoxia can account for all of the Ppa and the majority of the Psa response to obstructive apnea, 2) the ANS increases Psa but not Ppa in obstructive apnea, 3) the local effects of hypoxia associated with obstructive apnea cause vasodilation in the systemic vasculature and vasoconstriction in the pulmonary vasculature, and 4) a rise in Psa acts as an afterload to the heart and decreases SV over the course of the apnea.

Universal Primers for Amplification of Mitochondrial Small Subunit Ribosomal RNA-Encoding Gene in Scleractinian Corals

We describe the construction of polymerase chain reaction primers designed to amplify a portion of the mitochondrial (mt) small subunit ribosomal (SSU) RNA-encoding genes in scleractinian corals. Combinations of cloning and sequencing show that the amplified fragments are between 694 and 896 bp in length. Alignment of the amplified DNA sequences to the published mt SSU rRNA genes of Metridium senile and Sarcophyton glaucum indicates several conserved regions among actiniarian, corallimorpharian, octocorallian, and scleractinians, suggesting this primer set can successfully amplify over 80% of the mt SSU rDNA region of scleractinian corals. Surveys of sequence variation and estimation of the rate of evolution show an extremely slow divergence of the SSU rRNA gene in the family Acroporidae.

Effects of arousal and sleep state on systemic and pulmonary hemodynamics in obstructive apnea

During obstructive sleep apnea (OSA), systemic (Psa) and pulmonary (Ppa) arterial pressures acutely increase after apnea termination, whereas left and right ventricular stroke volumes (SV) reach a nadir. In a canine model (n = 6), we examined the effects of arousal, parasympathetic blockade (atropine 1 mg/kg iv), and sleep state on cardiovascular responses to OSA. In the absence of arousal, SV remained constant after apnea termination, compared with a 4.4 +/- 1.7% decrease after apnea with arousal (P < 0.025). The rise in transmural Ppa was independent of arousal (4.5 +/- 1.0 vs. 4.1 +/- 1.2 mmHg with and without arousal, respectively), whereas Psa increased more after apnea termination in apneas with arousal compared with apneas without arousal. Parasympathetic blockade abolished the arousal-induced increase in Psa, indicating that arousal is associated with a vagal withdrawal of the parasympathetic tone to the heart. Rapid-eye-movement (REM) sleep blunted the increase in Psa (pre- to end-apnea: 5.6 +/- 2.3 mmHg vs. 10.3 +/- 1.6 mmHg, REM vs. non-REM, respectively, P < 0.025), but not transmural Ppa, during an obstructive apnea. We conclude that arousal and sleep state both have differential effects on the systemic and pulmonary circulation in OSA, indicating that, in patients with underlying cardiovascular disease, the hemodynamic consequences of OSA may be different for the right or the left side of the circulation.

N-Myristoylation and betagamma play roles beyond anchorage in the palmitoylation of the G protein alpha(o) subunit

Many of the alpha subunits of heterotrimeric GTP-binding regulatory proteins (G proteins) are palmitoylated, a modification proposed to play a key role in the stable anchorage of the subunits to the plasma membrane. Palmitoylation of alpha subunits from the G(i) family is preceded by N-myristoylation, which alone or together with betagamma probably supports a reversible interaction of the alpha subunit with membrane as a prerequisite to the eventual incorporation of palmitate. Previous studies have not addressed, however, the question of whether membrane association alone, carried out through N-myristoylation, interaction with betagamma, or other events, is sufficient for palmitoylation. We report here for alpha(o) that it is not. We found that N-myristoylation is required for palmitoylation at least in part because it supports events subsequent to membrane attachment. Mutants of alpha(o) designed to target the subunit to membrane without an N-myristoyl group are unable to be palmitoylated as evaluated by incorporation of [(3)H]palmitate. Mutants of alpha(o) unable to interact normally with betagamma yet still attach to membrane demonstrate that betagamma, in contrast, is not required for palmitoylation. betagamma becomes necessary, however, when the N-myristoyl group is absent. Our results suggest that N-myristoylation and betagamma, while almost certainly relevant to the reversible interaction of alpha(o) with membrane, also play at least partly overlapping, post-anchorage roles in palmitoylation.

Synthesis of 9Z,11E-octadecadienoic and 10E,12Z-octadecadienoic acids, the major components of conjugated linoleic acid

Linoleic acid was efficiently converted into the two major components of conjugated linoleic acid, 9Z,11E-octadecadienoic (1a) and 10E,12Z-octadecadienoic acid (1b) using either the superbase (n-butyllithium/potassium tert-butoxide) or by simply refluxing with KOH in 1-butanol. In turn, 1a and 1b were separated from each other using the lipase from Aspergillus niger via stereoselective esterification in 1-butanol. This enzyme has a preference for the 9Z,11E isomer, 1a, and has excellent selectivity. This method has allowed the ready preparation of gram quantities of 1a and 1b in their highly purified forms, which are not readily accessible by current methods.

Serum vascular endothelial growth factor in epithelial ovarian neoplasms: correlation with patient survival

OBJECTIVE

To investigate the relationship between serum vascular endothelial growth factor (VEGF) and clinicopathological factors and to determine whether VEGF is an independent prognostic factor of ovarian cancer patients.

METHODS

Fifty-six women with International Federation of Gynecology and Obstetrics stages I to IV epithelial ovarian cancer undergoing surgery were enrolled. Clinical and pathologic items were recorded. Pretreatment VEGF serum samples of the 56 women were measured by an enzyme-linked immunosorbent assay. The results were correlated to clinical data. The histopathologic items and serum VEGF influencing clinical outcome were evaluated comparatively.

RESULTS

The median VEGF serum level in ovarian cancer patients was 458.7 pg/mL. The 75% quatile was defined as the cutoff level. Elevated vascular endothelial growth factor serum levels before therapy correlated significantly with poorer disease-free survival (DFS) (log rank test, P = 0.001) and overall survival (OS) (log rank test, P < 0.001) on all of the 56 patients. Besides, significantly reduced DFS (log rank test, P = 0.001) and OR (log rank test, P = 0.006) were also observed on 40 patients with residual disease less than 2 cm. High histologic grade (RR = 2.24 for DFS; RR = 2.38 for OS) and elevated serum VEGF levels (RR = 3.34 for DFS; RR = 4.47 for OS) are the prognostic factors on the 56 ovarian carcinoma patients by multivariate analyses. The advanced surgical staging (RR = 3.28 for DFS; RR = 3.84 for OS), high histologic grade (RR = 2.55 for DFS; RR = 2.44 for OS), and elevated serum VEGF levels (RR = 5.62 for DFS; RR = 5.37 for OS) are the prognostic factors for 40 ovarian carcinoma patients with residual disease less than 2 cm by multivariate analyses.

CONCLUSIONS

Pretreatment VEGF serum levels might be regarded as an additional factor in predicting the outcome of ovarian cancer patients. It also could provide prognostic information in clinically relevant subsets, such as those of residual disease less than 2 cm. Anti-angiogenic therapy, if is available, might be a new treatment modality for ovarian cancer patients with poor prognosis predicted by VEGF and other clinical parameters.

Sea urchin TgBMP2/4 gene encoding a bone morphogenetic protein closely related to vertebrate BMP2 and BMP4 with maximal expression at the later stages of embryonic development

We have cloned a gene fragment (named TgBMP2/4) that encodes a protein homologous to vertebrate bone morphogenetic protein (BMP) 2 and BMP4 in the sea urchin Tripneustes gratilla. This peptide sequence contains 204 amino acids with 7 conserved cysteine residues at the C-terminus of the coding region and a cluster of basic amino acids that may serve as a signal for proteolytic cleavage. Sequence comparison and phylogenetic analyses reveal that TgBMP2/4 is closely related to vertebrate BMP2 and BMP4 as well as to amphioxus BMP2/4, with similarity levels ranging from 90% to 94% at the mature C-terminal domain. Northern blot analyses show that a 6.3-kb TgBMP2/4 mRNA appears first at the mesenchyme blastula stage and increases to a maximal level at the gastrula and pluteus stages. This expression pattern is different from that of a BMP2/4-related gene previously found in sea urchin.

Vascular endothelial growth factor in cervical carcinoma

OBJECTIVE

To quantitate vascular endothelial growth factor of cervical carcinoma and elucidate its clinical correlation.

METHODS

Intratumoral protein levels of vascular endothelial growth factor were measured in 104 cervical cancer patients and in 30 cervical tissue specimens of benign gynecologic diseases as controls. The concentrations were correlated with clinical and pathologic characteristics.

RESULTS

The median concentrations of vascular endothelial growth factor in cervical cancer tissues were higher than those in benign cervical tissues (180.0 versus 0.0 pg/mg of protein, P < .001). Tumors larger than 4 cm (1030.0 versus 118.0 pg/mg of protein, P < .001) and with deep stromal invasion (364.0 versus 111.0 pg/mg of protein, P = .016) had higher levels than those smaller than 4 cm or with superficial stromal invasion. Higher levels were also found in tumors with lymphovascular emboli (568.0 versus 118.0 pg/mg of protein, P = .006), parametrial invasion (582.0 versus 117.0 pg/mg of protein, P = .04), and pelvic lymph node metastasis (759.5 versus 121.0 pg/mg of protein, P = .002) than in those without. The protein levels of vascular endothelial growth factor correlated positively with tumor sizes (r = 0.340, P < .001). Tumors with overexpressed VEGF were larger (3.35 +/- 1.17 versus 2.13 +/- 1.28 cm, P < .001) and had higher incidence of deep stromal invasion (20 of 57 versus 6 of 47, P = .009), lymphovascular emboli (15 of 33 versus 11 of 71, P = .011), parametrial invasion (15 of 32 versus 11 of 72, P = .002), and lymph node metastasis (10 of 20 versus 16 of 84, P = .004).

CONCLUSION

Intratumoral protein level of vascular endothelial growth factor in cervical cancer tissue correlates well with local tumor progression and tumor metastasis. Vascular endothelial growth factor might be a marker for evaluating disease severity.

Influence of histologic type and age on survival rates for invasive cervical carcinoma in Taiwan

OBJECTIVE

The aim of this study was to assess survival rates and to evaluate histologic type and age as prognostic factors for cervical carcinoma in an ethnically homogenous population in Taiwan.

METHODS

A retrospective analysis was conducted of 3678 cases of squamous cell carcinoma and adenocarcinoma that were diagnosed and treated for invasive cervical carcinoma between 1977 and 1994. Observed survival rates were estimated using the Kaplan-Meier method, and prognostic factors were assessed using Cox's proportional hazards regression analysis.

RESULTS

Correlating both FIGO stage and age with histologic type revealed a higher proportion of cases with adenocarcinoma in the lower FIGO stages (P = 0.0417). Further, we found that the younger the age group the higher the proportion of cases of cervical adenocarcinoma (P = 0.0006). The 5-year survival rate was lower for patients with adenocarcinoma than for patients with squamous cell carcinoma (66.5 vs 74.0%, P = 0.0009). The 5-year survival rates for FIGO stages I, II, III, and IV squamous cell carcinoma were 81.3, 75.2, 42.7, and 26.1%, respectively, while for adenocarcinoma they were 75.9, 62.9, 29.2, and 0%, respectively. The difference in survival rates between squamous cell carcinoma and adenocarcinoma was found mainly in stage I (P = 0.0039) and stage II (P = 0.0103), where radiotherapy was used as the primary treatment. Age also affected the overall Kaplan-Meier estimate of survival. The younger the age group, the better the survival rate (P < 0.0001). Multivariate analysis confirmed a highly significant association between survival rate and both histologic type (P < 0.0001) and age (P = 0.0037).

CONCLUSIONS

Early stage cervical cancer (stages I and II) with a glandular component had a lower 5-year survival rate than squamous cell carcinoma in cases where radiotherapy was the primary treatment. We speculate that this difference in survival rates between cervical adenocarcinoma and squamous cell carcinoma was due to the relative ineffectiveness of radiotherapy as a primary treatment in cases of adenocarcinoma.

Pregnancy with primary tubal placental site trophoblastic tumor--A case report and literature review

Placental site trophoblastic tumor (PSTT) is a rare trophoblastic neoplasm with malignant potential. The diagnosis and prognosis of this rare disease remain difficult. A case of tubal PSTT with the primary manifestation of internal bleeding at 30 weeks' gestation is presented. Emergency exploratory laparotomy and right partial salpingectomy were performed initially. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy were done immediately after cesarean section at 34 weeks' gestation. No further adjuvant therapy was given after surgery. No evidence of tumor recurrence or signs of metastasis were noted during 12 months of follow-up. Heterotopic pregnancy, one with intrauterine normal pregnancy and the other with implanting in the right fallopian tube and placental site trophoblastic tumor transformation, was proposed. To our knowledge, this is the first such case in the English literature.