Pre-treatment with chemotherapy can enhance the antigenicity and immunogenicity of tumours by promoting adaptive immune responses

Background:

Some cancer patients are immuno-compromised, and it has been long felt that immune-intervention is not compatible with standard chemotherapies. However, increasing evidence suggests that standard chemotherapy drugs may stimulate beneficial changes in both the immune system and tumour.

Methods:

We have assessed the expression of human leucocyte antigen class 1 (HLA1) on tumour cells before and after chemotherapy agents (cyclophosphamide, oxaliplatin or gemcitabine). In addition, we show that chemotherapy-stressed tumour cells may release cytokines that enhance the interactions between dendritic cells (DCs) and T cells into growth media.

Results:

Here we report that some chemotherapy agents can increase HLA1 expression in tumour cells, even when expression is low. Increases were associated with killing by cytotoxic T cells, which were negated by HLA1-blockade. Furthermore, T-cell function, as indicated by increased proliferation, was enhanced as supernatants derived from tumours treated with chemotherapy augmented DC-maturation and function.

Conclusion:

There is evidence that a facet of immune surveillance can be restored by appropriate chemotherapy agents. Also, tumours exposed to some chemotherapy may secrete cytokines that can mature DCs, which ultimately enhances T-cell responses.

Cell stress and translational inhibitors transiently increase the abundance of mammalian SINE transcripts

The abundance of Alu RNA is transiently increased by heat shock in human cell lines. This effect is specific to Alu repeats among Pol III transcribed genes, since the abundance of 7SL, 7SK, 5S and U6 RNAs is essentially unaffected by heat shock. The rapid induction of Alu expression precedes the heat shock induction of mRNAs for the ubiquitin and HSP 70 heat shock genes. Heat shock mimetics also transiently induce Alu expression indicating that increased Alu expression is a general cell-stress response. Cycloheximide treatment rapidly and transiently increases the abundance of Alu RNA. Again, compared with other genes transcribed by Pol III, this increase is specific to Alu. However, as distinguished from the cell stress response, cycloheximide does not induce expression of HSP 70 and ubiquitin mRNAs. Puromycin also increases Alu expression, suggesting that this response is generally caused by translational inhibition. The response of mammalian SINEs to cell stress and translational inhibition is not limited to SINEs which are Alu homologues. Heat shock and cycloheximide each transiently induce Pol III directed expression of B1 and B2 RNAs in mouse cells and C-element RNA in rabbit cells. Together, these three species exemplify the known SINE composition of placental mammals, suggesting that mammalian SINEs are similarly regulated and may serve a common function.

Dynamical behavior of epidemiological models with nonlinear incidence rates

Epidemiological models with nonlinear incidence rates lambda IpSq show a much wider range of dynamical behaviors than do those with bilinear incidence rates lambda IS. These behaviors are determined mainly by p and lambda, and secondarily by q. For such models, there may exist multiple attractive basins in phase space; thus whether or not the disease will eventually die out may depend not only upon the parameters, but also upon the initial conditions. In some cases, periodic solutions may appear by Hopf bifurcation at critical parameter values.

Influence of nonlinear incidence rates upon the behavior of SIRS epidemiological models

When the traditional assumption that the incidence rate is proportional to the product of the numbers of infectives and susceptibles is dropped, the SIRS model can exhibit qualitatively different dynamical behaviors, including Hopf bifurcations, saddle-node bifurcations, and homoclinic loop bifurcations. These may be important epidemiologically in that they demonstrate the possibility of infection outbreak and collapse, or autonomous periodic coexistence of disease and host. The possible mechanisms leading to nonlinear incidence rates are discussed. Finally, a modified general criterion for supercritical or subcritical Hopf bifurcation of 2-dimensional systems is presented.

Epidemiological models with age structure, proportionate mixing, and cross-immunity

Infection by one strain of influenza type A provides some protection (cross-immunity) against infection by a related strain. It is important to determine how this influences the observed co-circulation of comparatively minor variants of the H1N1 and H3N2 subtypes. To this end, we formulate discrete and continuous time models with two viral strains, cross-immunity, age structure, and infectious disease dynamics. Simulation and analysis of models with cross-immunity indicate that sustained oscillations cannot be maintained by age-specific infection activity level rates when the mortality rate is constant; but are possible if mortalities are age-specific, even if activity levels are independent of age. Sustained oscillations do not seem possible for a single-strain model, even in the presence of age-specific mortalities; and thus it is suggested that the interplay between cross-immunity and age-specific mortalities may underlie observed oscillations.

Alu transcripts: cytoplasmic localisation and regulation by DNA methylation

Full length Alu transcripts in HeLa cells are detected by primer extension using reverse transcriptase and are also analyzed as cloned cDNA sequences. The 5' end of these transcripts corresponds to the transcriptional start site for RNA polymerase III indicating that these RNAs are transcribed from their internal polymerase III promoters. The Alu transcripts found in cytoplasmic poly A+ RNAs appear to be organized into RNPs as assayed by sucrose gradient sedimentation. Present at about one hundred to one thousand copies per cell, the Alu transcripts are rare as compared to 7SL RNA. In agreement with previous reports that methylation inhibits Pol III-directed transcription of Alu in vitro, treatment of HeLa cells with 5-azacytidine results in Alu DNA hypomethylation and an increase in the abundance of the Alu transcript. Sequence analysis shows that many different Alu repeats including members of all subfamilies are transcribed by Pol III in vivo. cDNA sequences of the Pol III-directed transcripts exactly match the A box of the Pol III promoter element whereas in other Alu transcripts this element is not faithfully conserved.

Putamen-related regional and network functional deficits in first-episode schizophrenia with auditory verbal hallucinations

OBJECTIVE

Auditory verbal hallucinations (AVHs) are one of the cardinal symptoms of schizophrenia (SZ). Cerebral dysfunction may represent pathophysiological underpinnings behind AVHs in SZ. However, regional and network functional deficits for AVHs in SZ remain to be identified.

METHODS

Seventeen medication-naïve first-episode SZ patients with AVHs, 15 without AVHs, and 19 healthy controls (HCs) were studied using resting-state functional magnetic resonance imaging. We compared the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) among these subjects. Areas with both ALFF and ReHo alterations were used as seeds in functional connectivity (FC) analysis. Then we performed correlation analysis between image measures and symptoms and receiver operating characteristic analysis.

RESULTS

One-way analysis of variance showed significant differences of ALFF and ReHo in the bilateral putamen, thereby being used as seeds. SZ patients with AVHs showed decreased ALFF in the left putamen, increased ReHo in the right dorsolateral prefrontal cortex (DLPFC), and increased right putamen-seeded FC with the left DLPFC and Broca's area relative to those without AVHs. Furthermore, the increased strength of the connectivity between the right putamen and left Broca's area correlated with the severity of SZ symptoms. Both patient groups demonstrated hypoconnectivity within frontal/parietal/temporal cortico-striatal-cerebellar networks compared with HCs.

CONCLUSION

AVHs in SZ may be caused by abnormal regional function in the putamen and prefrontal cortex, as well as hyperconnectivity between them. The putamen-related regional and network functional deficits may reflect imbalance in neuromodulation of AVHs in SZ. Furthermore, dysconnectivity within cortico-striatal-cerebellar networks might subserve the pathogenesis of SZ.

Proposed roles for DNA methylation in Alu transcriptional repression and mutational inactivation

Methylation at CpG dinucleotides to produce 5 methyl cytosine (5me-C) has been proposed to regulate the transcriptional expression of human Alu repeats. Similarly, methylation has been proposed to indirectly favor the transpositional activity of young Alu repeats by transcriptionally inactivating older Alu's through the very rapid transition of 5me-C to T. Both hypotheses are examined here by RNA polymerase III (Pol III) in vitro transcription of Alu templates using HeLa cell extracts. A limiting factor represses the template activity of methylated Alu repeats. Competition by methylated prokaryotic vector DNA's relieves repression, showing that the factor is not sequence specific. This competitor has no effect on the activity of unmethylated templates showing that the repressor is highly specific toward methylated DNA. While methylation of a single pair of CpG dinucleotides in the A box of the Poll III promoter is sufficient to cause repression, methylation elsewhere within the template also causes repression. The repressor causing these effects on the Pol III directed transcription of Alu repeats is thought to be a previously reported, repressor for Pol II directed templates. Young Alu repeats are transcriptionally more active templates than a representative older Alu subfamily member. Also, younger Alu's form stable transcriptional complexes faster, potentially giving them an additional advantage. The mutation of three CpG's to CpA's within and near the A box drastically decreases both the template activity and rate of stable complex formation by a young Alu member. The sensitivity of Alu template activity to CpG transitions within the A box partially explains the selective transpositional advantage enjoyed by young Alu members.

Noradrenergic potentiation of cerebellar Purkinje cell responses to GABA: evidence for mediation through the beta-adrenoceptor-coupled cyclic AMP system

Previous in vivo studies from our laboratory have consistently shown that iontophoretically applied norepinephrine (NE) can potentiate gamma-aminobutyric acid (GABA)-induced depressant responses of cerebrocortical, cerebellar and hypothalamic neurons. Additional experiments have further suggested that this noradrenergic facilitating action is specific for GABA and results from the activation of a beta-type adrenoceptor. The goal of the present studies was to determine if the cAMP second messenger system might also be a component of the mechanism responsible for this NE modulatory action on GABA-mediated inhibition. In one set of in vitro experiments, we examined cerebellar neuronal responses to GABA before, during and after iontophoretic application of NE, 8-bromo-3',5'-cyclic AMP (BcAMP) or 3-isobutyl-1-methyl xanthine (IBMX) or bath application of forskolin (10-30 microM). In a second group of in vivo studies, extracellularly recorded responses of individual cerebellar Purkinje (P) cells to iontophoretic pulses of GABA or beta-alanine were examined before, during and after NE or BcAMP microiontophoresis. In 20 of 25 cerebellar cells recorded from tissue slices, iontophoretically applied NE markedly enhanced responses to GABA in a manner similar to that observed previously in vivo. In these in vitro preparations, bath application of forskolin was also capable of potentiating GABA-induced inhibition in each of 4 cases tested whereas dideoxy-forskolin was not. Iontophoretic application of IBMX further enhanced the facilitating effects of NE on GABA-induced inhibition in 10 of 11 cases tested. Furthermore, under in vitro conditions, BcAMP augmented inhibitory responses to GABA in all cerebellar neurons tested. In the intact rat brain, iontophoretic administration of BcAMP caused a marked NE-like augmentation of P-cell responses to GABA in 73% of the cells tested. As with NE, BcAMP was ineffective in enhancing P-cell inhibitory responses to beta-alanine, an agent which like GABA causes hyperpolarization, by increasing Cl conductance. In summary, these results indicate that a membrane permeant analog of cAMP, a phosphodiesterase inhibitor and an agent which directly activates adenyl cyclase can mimic the previously observed GABA-potentiating actions of NE. Thus, these findings provide further support for the contention that noradrenergic enhancement of GABA inhibition results from a cascade of transmembrane events which includes beta-receptor activation, adenyl cyclase stimulation and increased intracellular production of cAMP.

Laparoscopic bipolar coagulation of uterine vessels: a new method for treating symptomatic fibroids

OBJECTIVE

To evaluate the effects of laparoscopic bipolar coagulation of uterine vessels in treating symptomatic fibroids.

DESIGN

Prospective clinical study.

SETTING

University-affiliated tertiary referral center.

PATIENT(S)

Eighty-seven women with symptomatic fibroids warranting surgical treatment and wanting to retain their uteri.

INTERVENTION(S)

Laparoscopic bipolar coagulation of uterine arteries and anastomotic sites of uterine arteries with ovarian arteries.

MAIN OUTCOME MEASURE(S)

Percentage reduction in the dominant fibroid size and clinical response evaluation.

RESULT(S)

Eighty-five (97.7%) of 87 patients underwent technically successful laparoscopic coagulation of uterine vessels without intraoperative complications. The mean follow-up time was 10.2 months. Symptomatic improvement was reported in 76 (89.4%) of 85 patients, including 18 (21.2%) with complete resolution of symptoms. Significant reductions in the dominant fibroid size (average, 76%) and the uterine volume (average, 46%) were sonographically demonstrated. Two patients conceived 4 and 9 months, respectively, after treatment. Three (3.5%) premenopausal women became postmenopausal postoperatively.

CONCLUSION(S)

Laparoscopic bipolar coagulation of uterine vessels appears to be a promising new method for treating fibroid-related menorrhagia and pelvic pain.

Laparoscopic bipolar coagulation of uterine vessels to treat symptomatic leiomyomas

Laparoscopic bipolar coagulation of uterine vessels was performed in three women with symptomatic myomas who required conventional surgical treatment. Uterine size and dominant myoma size were assessed by ultrasonography before and after surgery. Both uterine arteries, as well as anastomosis zone of uterine arteries with ovarian arteries, were occluded in all three women. Surgery was uneventful, and patients were hospitalized for only 2 days. All women experienced improvement in symptoms with no complications. Postoperative ultrasound showed progressive reduction in size of the dominant myoma. A larger series and longer follow-up are required to evaluate long-term effects and to identify appropriate candidates.

The development and initial validation of the Multicultural Environmental Inventory: a preliminary investigation

This article describes the development and initial validation of the Multicultural Environmental Inventory (MEI). The MEI is an instrument designed to measure an individual's perceptions about the degree to which graduate counseling programs address multicultural issues within curriculum, supervision, climate, and research. This investigation was conducted using the data from 208 students and faculty from counseling psychology graduate programs across the United States approved by the American Psychological Association. By using techniques of exploratory factor analysis, a 4-factor solution was determined to account for the relationships among the items on the MEI. The instrument was modified from 53 to 27 items on the basis of the items' effectiveness in measuring the underlying constructs of interest, and internal consistency information is provided on the final revised instrument (MEI-R). The factors underlying the MEI-R are discussed within the context of a multicultural environment in graduate counseling programs, and directions for future research are considered.

RNA polymerase III promoter and terminator elements affect Alu RNA expression

Promoter elements derived from the 7SL RNA gene stimulate RNA polymerase III (Pol III) directed Alu transcription in vitro. These elements also stimulate expression of Alus transfected into 293 cells, but transcripts from these same constructs are undetectable in HeLa cells. A terminator resembling the terminator for the 7SL RNA gene has no effect on in vitro Alu template activity, but increases expression in vivo in a position independent manner. Alu transcripts generated from templates with and without this terminator have identical half-lives, indicating that this terminator stimulates expression by increasing template activity. Together, these results show that Alu expression may be regulated at multiple levels and can respond to cis-acting elements. This new found ability to express Alu transcripts by transient transfection provides an opportunity to monitor their post-transcriptional fate. Primary Alu transcripts are not extensively adenylated or deadenylated following transcription, but are short-lived compared to 118 nt scAlu RNA. In addition to Alu RNA, transfected templates encode scAlu RNA, but very high levels of Alu RNA expression does not increase the abundance of scAluRNA. ScAluRNA is not merely a transient RNA degradation product, but is instead tightly regulated by factors other than the abundance of primary transcripts.

Major complications of operative and diagnostic laparoscopy for gynecologic disease

STUDY OBJECTIVE

To compare complication rates of diagnostic and operative laparoscopy. Design. Retrospective study (Canadian Task Force classification II-2).

SETTING

One medical center and three teaching hospitals.

PATIENTS

Six thousand four hundred fifty-one women with various indications for laparoscopic diagnosis and/or laparoscopic surgery from January 1994 through June 1999.

INTERVENTION

Diagnostic and operative laparoscopies.

MEASUREMENTS AND MAIN RESULTS

Forty-two major complications occurred that directly resulted in one death. One patient had stomach injury, 3 had major vessel injuries, 5 had ureter injuries, 10 had intestinal injuries, and 23 had bladder injuries. The overall complication rate for all laparoscopies was 0.65% (42/6451); however, it rose to 0.80% (39/4865) for operative laparoscopy compared with 0.19% for diagnostic laparoscopy (3/1586; p <0.001, Fisher's exact test).

CONCLUSION

Laparoscopic surgery is appropriate for managing various gynecologic diseases and has an acceptable complication rate. However, operative laparoscopy should be performed carefully because its rate of complications is significantly higher than that of diagnostic laparoscopy, especially for laparoscopic-assisted vaginal hysterectomy. (J Am Assoc Gynecol Laparosc 8(1):68-73, 2001)

Phylogenetic evidence for multiple Alu source genes

A member of the young PV Alu subfamily is detected in chimpanzee DNA showing that the PV subfamily is not specific to human DNA. This particular Alu is absent from the orthologous loci in both human and gorilla DNAs, indicating that PV subfamily members transposed within the chimpanzee lineage following the divergence of chimpanzee from both gorilla and human. These findings and previous reports describing the transpositional activity of other Alu sequences within the human, gorilla, and chimpanzee lineages provide phylogenetic evidence for the existence of multiple Alu source genes. Sequences surrounding this particular Alu resemble known transcriptional control elements associated with RNA polymerase III, suggesting a mechanism by which cis-acting elements might be acquired upon retrotransposition.

Anterior cingulate cortex-related connectivity in first-episode schizophrenia: a spectral dynamic causal modeling study with functional magnetic resonance imaging

Understanding the neural basis of schizophrenia (SZ) is important for shedding light on the neurobiological mechanisms underlying this mental disorder. Structural and functional alterations in the anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), hippocampus, and medial prefrontal cortex (MPFC) have been implicated in the neurobiology of SZ. However, the effective connectivity among them in SZ remains unclear. The current study investigated how neuronal pathways involving these regions were affected in first-episode SZ using functional magnetic resonance imaging (fMRI). Forty-nine patients with a first-episode of psychosis and diagnosis of SZ-according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision-were studied. Fifty healthy controls (HCs) were included for comparison. All subjects underwent resting state fMRI. We used spectral dynamic causal modeling (DCM) to estimate directed connections among the bilateral ACC, DLPFC, hippocampus, and MPFC. We characterized the differences using Bayesian parameter averaging (BPA) in addition to classical inference (t-test). In addition to common effective connectivity in these two groups, HCs displayed widespread significant connections predominantly involved in ACC not detected in SZ patients, but SZ showed few connections. Based on BPA results, SZ patients exhibited anterior cingulate cortico-prefrontal-hippocampal hyperconnectivity, as well as ACC-related and hippocampal-dorsolateral prefrontal-medial prefrontal hypoconnectivity. In summary, spectral DCM revealed the pattern of effective connectivity involving ACC in patients with first-episode SZ. This study provides a potential link between SZ and dysfunction of ACC, creating an ideal situation to associate mechanisms behind SZ with aberrant connectivity among these cognition and emotion-related regions.

Prediction of protein structural classes by modified mahalanobis discriminant algorithm

We first discuss quantitative rules for determining the protein structural classes based on their secondary structures. Then we propose a modification of the least Mahalanobis distance method for prediction of protein classes. It is a generalization of a quadratic discriminant function to the case of degenerate covariance matrices. The resubstitution tests and leave-one-out tests are carried out to compare several methods. When the class sample sizes or the covariance matrices of different classes are significantly different, the modified method should be used to replace the least Mahalanobis distance method. Two lemmas for the derivation of our new algorithm are proved in an appendix.

Effects of anandamide on embryo implantation in the mouse

Anandamide (N-arachidonoylethanolamine), an arachidonic acid derivative, is an endogenous ligand for both the brain-type (CB1-R) and spleen-type (CB2-R) cannabinoid receptors. To investigate the possible effects of anandamide on embryo implantation in the mouse, we used a co-culture system in which mouse embryos are cultured with a monolayer of uterine epithelial cells. Our results indicate that 14 nM anandamide significantly promotes the attachment and outgrowth of the blastocysts on the monolayer of uterine epithelial cells, and those effects could be blocked by CB1-R antagonists SR141716A, but not by SR144528, a CB2-R antagonist. It suggests that the effects of anandamide on embryo attachment and outgrowth are mediated by CB1-R. However, 56 nM anandamide is capable of inhibiting the blastocyst attachment and outgrowth, we, therefore, conclude that anandamide may play an essential role at the outset of implantation.

Reduction of blood pressure with calcium and potassium supplementation in children with salt sensitivity: a 2-year double-blinded placebo-controlled trial

An investigation of the reductive effect of blood pressure and increment of urinary sodium excretion with calcium and potassium supplementation in children with sodium sensitivity is conducted. In total of 261 school children who had completed a 2-year double-blinded, placebo-controlled trial with calcium and potassium supplementation salt sensitivity, with a salt volume expansion and contraction protocol, was determined. The results showed that in children with salt sensitivity, the increase in blood pressure in the supplementary group was lower by 4.3/4.8 mmHg than that in the placebo group (P<0.05), while no significant change was found between the supplementary group and placebo group in children with nonsalt sensitivity. With calcium and potassium supplementation, the night urinary sodium excretion in children with salt sensitivity was significantly increased (P<0.01), and it is negatively correlated with the increase in blood pressure. It was suggested that a moderate increase of calcium and potassium intake in children with salt sensitivity, through interaction with sodium, can promote urinary sodium excretion and may play contribute to the prevention of hypertension.

Successful treatment of symptomatic arteriovenous malformation of the uterus using laparoscopic bipolar coagulation of uterine vessels

OBJECTIVE

To report a case of symptomatic arteriovenous malformation (AVM) of the uterus that was successfully treated with laparoscopic bipolar coagulation of uterine vessels.

DESIGN

Case report.

SETTING

University-affiliated tertiary referral center.

PATIENT(S)

A 66-year-old woman with symptomatic AVM of the uterus.

INTERVENTION(S)

Laparoscopic bipolar coagulation of uterine vessels.

MAIN OUTCOME MEASURE(S)

Clinical symptoms, color Doppler sonographic examination, and pelvic magnetic resonance imaging.

RESULT(S)

Remarkable shrinkage of the lesion size, obvious decrease in all of the impedance measurements (pulsatility, resistance, velocity indexes [systolic/diastolic]), and freedom from symptoms.

CONCLUSION(S)

This modality is a new alternative method for the management of patients with symptomatic AVM of the uterus who do not respond to conservative treatment.

What's missing from multicultural competency research: review, introspection, and recommendations

Much of the multicultural counseling research has pointed out the need for counselors to become culturally competent to appropriately address the needs of an emerging diverse community. To date, however, this body of research has largely focused on counselor competencies, with little attention being given to the client perspective of multicultural counseling competencies. This article discusses the importance of integrating the client perspective within the historical context of the multicultural literature by examining client preferences and expectations, as well as the adequacy of the current empirical data. The authors also raise the issue of politics inherent in multiculturalism and discuss how this affects the research. A number of recommendations are made as a guide for future research.

Glial localization of adenylate-cyclase-coupled beta-adrenoceptors in rat forebrain slices

Fluorocitrate (FC), a selective inhibitor of glial cell respiration, was used to estimate the extent to which glial cells contain adenylate cyclase-coupled beta-adrenoceptors in rat brain slices. The drug blocked 75-95% of the elevation of cyclic AMP caused by the beta-agonist, isoproterenol, in the 4 forebrain regions sampled (frontal and parietal cortex, caudate nucleus, olfactory tubercle). Intracellular recording of neurons in the treated slices confirmed that they were unaffected by FC. Treatment with the neurotoxin, kainic acid, eliminated all electrophysiological activity but did not affect the cAMP response. The results indicate that glial cells contain the preponderance of adenylate-cyclase-coupled beta-adrenoceptors in slices of the rat forebrain and may constitute an important target of the central noradrenergic system in vivo.

Nonlinear oscillations in models of immune responses to persistent viruses

This paper compares several population models for HIV dynamics. The effect of perfect or nonperfect drugs proposed by Ho, Perelson, and others are considered in the more complicated models of Nowak and Bangham for immune responses to persistent viruses. It is pointed out that two models proposed by Nowak and Bangham have different dynamical behaviors. One of them can have sustained oscillations via the Hopf bifurcation and the other does not. To overcome the difficulty in symbolic computations for complicated systems, we use parameter transforms and introduce a semisymbolic method. This method is very efficient in finding Hopf bifurcation parameters and can be used for other models.

Tetraspanin CD9 regulates invasion during mouse embryo implantation

The expression of tetraspanin CD9 was found on blastocysts in mice and endometrium epithelial cells in human and bovine. However, it remains unknown how CD9 is involved in the precise dialogue between embryo and uterus during early pregnancy. This study was designed to investigate the functional roles of CD9 in the embryo implantation with monoclonal antibody against CD9 protein (anti-CD9 mAb) and antisense oligonucleotide against CD9 gene (AS-CD9). Our results showed that intrauterine injection of anti-CD9 mAb on day 4 of pregnancy significantly increased the number of embryos implanted (7.24+/-0.39 versus 4.04+/-0.38). In vitro, anti-CD9 mAb or AS-CD9 significantly enhanced embryo-outgrowth ability on the monolayer of uterus epithelial cells in a dose-dependent manner. However, the attachment of blastocysts to epithelial cells was unaffected. Furthermore, we found that anti-CD9 mAb or AS-CD9 stimulated matrix metalloproteinase 2 (MMP-2) production of blastocysts on Fibronectin. LY294002, a specific inhibitor of phosphoinositide 3-kinase, was able to counteract the effect of anti-CD9 mAb and AS-CD9 on outgrowth ability and production of MMP-2. Our results indicated that CD9 played a role of inhibiting embryo implantation. CD9 was able to impair embryo invasion and the production of MMP-2 through the phosphoinositide 3-kinase signaling pathway.