Pathogenic/likely pathogenic mutations identified in Vietnamese children diagnosed with autism spectrum disorder using high-resolution SNP genotyping platform.

Among the most prevalent neurodevelopmental disorders, Autism Spectrum Disorder (ASD) is highly diverse showing a broad phenotypic spectrum. ASD also couples with a broad range of mutations, both de novo and inherited. In this study, we used a proprietary SNP genotyping chip to analyze the genomic DNA of 250 Vietnamese children diagnosed with ASD. Our Single Nucleotide Polymorphism (SNP) genotyping chip directly targets more than 800 thousand SNPs in the genome. Our primary focus was to identify pathogenic/likely pathogenic mutations that are potentially linked to more severe symptoms of autism. We identified and validated 23 pathogenic/likely pathogenic mutations in this initial study. The data shows that these mutations were detected in several cases spanning multiple biological pathways. Among the confirmed SNPs, mutations were identified in genes previously known to be strongly associated with ASD such as SLCO1B1, ACADSB, TCF4, HCP5, MOCOS, SRD5A2, MCCC2, DCC, and PRKN while several other mutations are known to associate with autistic traits or other neurodevelopmental disorders. Some mutations were found in multiple patients and some patients carried multiple pathogenic/likely pathogenic mutations. These findings contribute to the identification of potential targets for therapeutic solutions in what is considered a genetically heterogeneous neurodevelopmental disorder.

[The application of a new type of sterile elastic exsanguination tourniquet in aspiration surgery for upper limb lymphedema].

Objective: To evaluate the effect of a new type of sterile elastic exsanguination tourniquet (SEET) in aspiration surgery for upper limb lymphedema. Methods: The clinical data of 159 patients who underwent aspiration surgery for upper limb lymphedema from January 2017 to June 2022 in the Beijing Shijitan Hospital, Capital Medical University were retrospectively analyzed. Among them, 54 patients were treated with SEET (SEET group), while 105 patients were not treated with SEET (No-SEET group). The propensity score matching method was used, and the surgical indicators and complications were compared between the two groups. The factors affecting intraoperative bleeding volume were analyzed through multiple linear regression analysis. Results: A total of 49 pairs of patients were successfully matched by the propensity score method. The age of patients in the SEET and No-SEET groups was (57.7±8.9) years and (56.8±9.1) years, respectively. Compared with the Non-SEET group, the SEET group had less bleeding volume [(311±164) ml vs (437±173) ml, P<0.001]. The results of multiple linear regression analysis showed that the factors affecting intraoperative bleeding volume included age (ß=-0.142, P=0.041), using the SEET (ß=-0.249, P=0.002), surgical time (ß=0.195, P=0.010) and the amount of fat mixture sucked out (ß=0.464, P<0.001). Conclusions: The clinical application of the SEET in aspiration surgery for upper limb lymphedema is safe, and can significantly reduce the bleeding volume and alleviate blood shortage.

ATP-Responsive Nanoparticles Covered with Biomolecular Machine "Chaperonin GroEL".

Herein, we report an ATP-responsive nanoparticle (GroEL NP) whose surface is fully covered with the biomolecular machine "chaperonin protein GroEL". GroEL NP was synthesized by DNA hybridization between a gold NP with DNA strands on its surface and GroEL carrying complementary DNA strands at its apical domains. The unique structure of GroEL NP was visualized by transmission electron microscopy including under cryogenic conditions. The immobilized GroEL units retain their machine-like function and enable GroEL NP to capture denatured green fluorescent protein and release it in response to ATP. Interestingly, the ATPase activity of GroEL NP per GroEL was 4.8 and 4.0 times greater than those of precursor cys GroEL and its DNA-functionalized analogue, respectively. Finally, we confirmed that GroEL NP could be iteratively extended to double-layered ( GroEL ) 2 ${{^{({\rm GroEL}){_{2}}}}}$ NP.

Structural basis of receptor usage by the engineered capsid AAV-PHP.eB.

Adeno-associated virus serotype 9 (AAV9) is a promising gene therapy vector for treating neurodegenerative diseases due to its ability to penetrate the blood-brain barrier. PHP.eB was engineered from AAV9 by insertion of a 7-amino acid peptide and point mutation of neighboring residues, thereby enhancing potency in the central nervous system. Here, we report a 2.24-Å resolution cryo-electron microscopy structure of PHP.eB, revealing conformational differences from other 7-mer insertion capsid variants. In PHP.eB, the 7-mer loop adopts a bent conformation, mediated by an interaction between engineered lysine and aspartate residues. Further, we identify PKD2 as the main AAV receptor (AAVR) domain recognizing both AAV9 and PHP.eB and find that the PHP.eB 7-mer partially destabilizes this interaction. Analysis of previously reported AAV structures together with our pull-down data demonstrate that the 7-mer topology determined by the lysine-aspartate interaction dictates AAVR binding strength. Our results suggest that PHP.eB's altered tropism may arise from both an additional interaction with LY6A and weakening of its AAVR interaction. Changing the insertion length, but not sequence, modifies PKD2 binding affinity, suggesting that a steric clash impedes AAVR binding. This research suggests improved library designs for future AAV selections to identify non-LY6A-dependent vectors and modulate AAVR interaction strength.

[Lower extremity lymphedema as the initial symptom of malignant disease].

To investigate the diagnosis of malignancy with lower extremity lymphedema as the initial manifestation. We performed a retrospective study of 33 patients with malignant lymphedema treated at the Department of Lymphatic Surgery, Beijing Shijitan Hospital, Capital Medical University, from May 22, 2007 to December 31, 2018. A total of 33 cases of lower extremity lymphedema caused or aggravated by malignant tumors were found. The age range of 33 patients with malignant lymphedema was 21 to 84 years. Twenty-two patients were male, and 11 patients were female, with a mean age of (57.5±15.0) years. The time from the occurrence of lymphedema to the diagnosis of malignant tumors ranged from a month to 2 years. The proportion of patients with abnormal tumor markers was 88.9% (24/27), the prevalence of anemia among patients with malignant lymphedema was 42.4% (14/33), and the positive rates of ultrasonography, CT, MRI, and radionuclide imaging were 100.0% (17/17), 100.0% (25/25), 100.0% (4/4) and 60.0% (12/20), respectively. Twenty-seven cases with malignant tumors were confirmed by pathological diagnosis. To avoid delays in the diagnosis and therapy of malignant lymphedema, physicians should actively look for signs or symptoms of lymphedema during the follow-up period and promptly manage patients developing problems.

HIV latency can be established in proliferating and nonproliferating resting CD4+ T cells in vitro: implications for latency reversal.

OBJECTIVE: To determine whether latency can be established and reversed in both proliferating and nonproliferating CD4+ T cells in the same model in vitro. METHODS: Activated CD4+ T cells were infected with either a nonreplication competent, luciferase reporter virus or wild-type full-length enhanced green fluorescent protein (EGFP) reporter virus and cultured for 12 days. The cells were then sorted by flow cytometry to obtain two distinct T-cell populations that did not express the T-cell activation markers, CD69, CD25 and human leukocyte antigen (HLA)-DR: CD69CD25HLA-DR small cells (nonblasts) that had not proliferated in vitro following mitogen stimulation and CD69CD25HLA-DR large cells (which we here call transitional blasts) that had proliferated. The cells were then reactivated with latency-reversing agents and either luciferase or EGFP quantified. RESULTS: Inducible luciferase expression, consistent with latent infection, was observed in nonblasts and transitional blasts following stimulation with either phorbol-myristate-acetate/phytohemagglutinin (3.8 ±â€Š1 and 2.9 ±â€Š0.5 fold above dimethyl sulfoxide, respectively) or romidepsin (2.1 ±â€Š0.6 and 1.8 ±â€Š0.2 fold above dimethyl sulfoxide, respectively). Constitutive expression of luciferase was higher in transitional blasts compared with nonblasts. Using wild-type full-length EGFP reporter virus, inducible virus was observed in nonblasts but not in transitional blasts. No significant difference was observed in the response to latency-reversing agents in either nonblasts or transitional blasts. CONCLUSION: HIV latency can be established in vitro in resting T cells that have not proliferated (nonblasts) and blasts that have proliferated (transitional blasts). This model could potentially be used to assess new strategies to eliminate latency.

[Effect of intranasal excision on nasal vestibular cyst under nasal endoscopy].

Objective: To observe the clinical effects of intranasal excision on nasal vestibular cyst under nasal endoscopy. Methods: Forty-two cases of nasal vestibular cyst diagnosed in the Department of Otorhinolaryngology Head and Neck Surgery, Tianjin Third Central Hospital between Feb. 2011 and Jan. 2016 were treated by intranasal excision under nasal endoscope. Results: All the 42 patients were cured without any complication. The rate of complete stripping was 78.6% (33/42), with operating time of (21.31±4.04) min and bleeding amount of (10.26±2.13) ml. During follow-up ranged from 6 months to 5 years, with the median follow-up time being 19.6 months, no post-operative recurrence and complication were found. Conclusion: Intranasal excision for nasal vestibular cyst under nasal endoscopy is an effective method, which can be widely used in hospitals.

CXCR5(+) follicular cytotoxic T cells control viral infection in B cell follicles.

During unresolved infections, some viruses escape immunological control and establish a persistant reservoir in certain cell types, such as human immunodeficiency virus (HIV), which persists in follicular helper T cells (TFH cells), and Epstein-Barr virus (EBV), which persists in B cells. Here we identified a specialized group of cytotoxic T cells (TC cells) that expressed the chemokine receptor CXCR5, selectively entered B cell follicles and eradicated infected TFH cells and B cells. The differentiation of these cells, which we have called 'follicular cytotoxic T cells' (TFC cells), required the transcription factors Bcl6, E2A and TCF-1 but was inhibited by the transcriptional regulators Blimp1, Id2 and Id3. Blimp1 and E2A directly regulated Cxcr5 expression and, together with Bcl6 and TCF-1, formed a transcriptional circuit that guided TFC cell development. The identification of TFC cells has far-reaching implications for the development of strategies to control infections that target B cells and TFH cells and to treat B cell-derived malignancies.

Toxicity and in vitro activity of HIV-1 latency-reversing agents in primary CNS cells.

Despite the success of combination antiretroviral therapy (cART), HIV persists in long lived latently infected cells in the blood and tissue, and treatment is required lifelong. Recent clinical studies have trialed latency-reversing agents (LRA) as a method to eliminate latently infected cells; however, the effects of LRA on the central nervous system (CNS), a well-known site of virus persistence on cART, are unknown. In this study, we evaluated the toxicity and potency of a panel of commonly used and well-known LRA (panobinostat, romidepsin, vorinostat, chaetocin, disulfiram, hexamethylene bisacetamide [HMBA], and JQ-1) in primary fetal astrocytes (PFA) as well as monocyte-derived macrophages as a cellular model for brain perivascular macrophages. We show that most LRA are non-toxic in these cells at therapeutic concentrations. Additionally, romidepsin, JQ-1, and panobinostat were the most potent at inducing viral transcription, with greater magnitude observed in PFA. In contrast, vorinostat, chaetocin, disulfiram, and HMBA all demonstrated little or no induction of viral transcription. Together, these data suggest that some LRA could potentially activate transcription in latently infected cells in the CNS. We recommend that future trials of LRA also examine the effects of these agents on the CNS via examination of cerebrospinal fluid.

Using [¹8F]FBAU for imaging brain tumor progression in an F98/tk-luc glioma-bearing rat model.

1-(2-Deoxy-2-[18F]fluoro-ß-D-arabinofuranosyl)-5-bromouracil ([18F]FBAU), a substitute for thymine, has been reported as an effective reporter probe by which to trace cellular metabolism with its positron emission. In the present study, a rat xenograft model bearing F98 glioma transfected with dual reporter genes, herpes simplex virus type 1 thymidine kinase (HSV1-tk) and firefly luciferase (luc) was used for monitoring tumor progression by multimodalities of molecular imaging using [18F]FBAU and D-luciferase as probes. Rat F98 glioma cells were transfected with the pC1-tk-IRES-luc vectors. The selected stable clone was renamed as the F98/tk-luc cell line. Fischer 344 male rats bearing orthotropic F98/tk-luc gliomas in the left brain were used. On day 13 post tumor inoculation, biodistribution, positron emission tomography (PET), magnetic resonance imaging (MRI) and ex vivo autoradiography were performed. The surviving fraction of F98/tk-luc cells treated with 15 µM ganciclovir (GCV) was 15.9%, and the uptake of [131I]FIAU in these cells was significantly enhanced when compared with F98 cells. The correlation coefficient of tumor volume vs. the bioluminescence in the F98/tk-luc glioma-bearing rats was 0.90. The biodistribution showed that the accumulation ratios of [18F]FBAU for glioma-to-normal brain were 9.16, 14.24, 5.7 and 13.7 at 30, 60, 90 and 120 min post i.v. injection, respectively. Consistent tumor enhancement of [18F]FBAU/PET imaging was also noted from 30-90 min post injection. Ex vivo autoradiography also confirmed significant [18F]FBAU uptake in tumors. In conclusion, [18F]FBAU may be used as a PET probe for monitoring glioma progression in animal models and may have potential for clinical use as well.

Curcumin synergistically enhances the radiosensitivity of human oral squamous cell carcinoma via suppression of radiation-induced NF-κB activity.

The anticancer effect of curcumin has been widely reported. However, whether curcumin can enhance the radiosensitivity of human oral squamous cell carcinoma (OSCC) remains to be elucidated. The aim of the present study was to evaluate the efficacy of curcumin combined with radiation against OSCC. SAS cells were transfected with the luciferase gene (luc) and named SAS/luc. NF-κB/DNA binding activity, the surviving fraction and NF-κB-regulated effector protein expression were determined by electrophoretic mobility shift assay, clonogenic survival assay and western blotting, respectively. The therapeutic efficacy was evaluated in SAS/luc tumor-bearing mice by caliper measurement and bioluminescence imaging. Curcumin enhanced SAS/luc radiosensitivity through the inhibition of radiation-induced NF-κB activity and expression of effector proteins both in vitro and in vivo. With 4 Gy or greater radiation doses, synergistic effects of curcumin were observed. The combination group (curcumin plus radiation) had significantly better tumor control compared with that of curcumin or radiation alone. No significant body weight change of mice was found throughout the entire study. In conclusion, curcumin is a radiosensitizer against OSCC with negligible toxicity.

Entinostat is a histone deacetylase inhibitor selective for class 1 histone deacetylases and activates HIV production from latently infected primary T cells.

OBJECTIVES: To compare the potency, toxicity and mechanism of action of multiple histone deacetylase inhibitors (HDACi) in activating HIV production from latency. DESIGN: In-vitro analysis of HDACi in a primary T-cell model of HIV latency and latently infected cell lines. METHODS: Latently infected chemokine ligand 19 (CCL19)-treated CD4⁺ T cells and the latently infected cell lines ACH2 and J-Lat were treated with a panel of HDACi, including entinostat, vorinostat, panonbinostat and MCT3. Viral production and cell viability were compared. Expression of cellular HDACs was measured by western blot and PCR. Association of HDACs with the HIV long-terminal repeat (LTR) using latently infected CCL19-treated primary CD4⁺ T cells in the presence and absence of specific HDACi was determined by chromatin immunoprecipitation (ChIP). RESULTS: We demonstrated considerable variation in the potency and toxicity of HDACi in latently infected primary CD4⁺ T cells and cell lines. All HDACi tested activated HIV production in latently infected primary T cells with greatest potency demonstrated with entinostat and vorinostat and greatest toxicity with panobinostat. Following the addition of HDACi in vitro, there were no changes in markers of T-cell activation or expression of the HIV coreceptors chemokine (C-X-C motif) receptor 4 (CXCR4) or chemokine (C-C motif) receptor type 5 (CCR5). ChIP analysis of latently infected CCL19-treated primary CD4⁺ T cells showed binding by HDAC1, HDAC2 and HDAC3 to the LTR with removal of HDAC1 and HDAC2 following treatment with the HDACi vorinostat and HDAC1 only following treatment with entinostat. CONCLUSION: The HDACi entinostat, selective for inhibition of class I HDACs, induced virus expression in latently infected primary CD4⁺ T cells making this compound an attractive novel option for future clinical trials.

Imaging, autoradiography, and biodistribution of (188)Re-labeled PEGylated nanoliposome in orthotopic glioma bearing rat model.

The (188)Re-labeled pegylated nanoliposome (abbreviated as (188)Re-Liposome) was prepared and evaluated for its potential as a theragnostic agent for glioma. (188)Re-BMEDA complex was loaded into the pegylated liposome core with pH 5.5 ammonium sulfate gradient to produce (188)Re-Liposome. Orthotopic Fischer344/F98 glioma tumor-bearing rats were prepared and intravenously injected with (188)Re-Liposome. Biodistribution, pharmacokinetic study, autoradiography (ARG), histopathology, and nano-SPECT/CT imaging were conducted for the animal model. The result showed that (188)Re-Liposome accumulated in the brain tumor of the animal model from 0.28%±0.09% injected dose (ID)/g (n=3) at 1 hour to a maximum of 1.95%±0.35% ID/g (n=3) at 24 hours postinjection. The tumor-to-normal brain uptake ratio (T/N ratio) increased from 3.5 at 1 hour to 32.5 at 24 hours. Both ARG and histopathological images clearly showed corresponding tumor regions with high T/N ratios. Nano-SPECT/CT detected a very clear tumor image from 4 hours till 48 hours. This study reveals the potential of (188)Re-Liposome as a theragnostic agent for brain glioma.

Host attachment, invasion, and stimulation of proinflammatory cytokines by Campylobacter concisus and other non-Campylobacter jejuni Campylobacter species.

BACKGROUND: Campylobacter concisus and other non-Campylobacter jejuni Campylobacter species have been implicated in the initiation of gastrointestinal diseases. In the present study, we investigated the interaction between these bacteria and the human intestinal epithelium and immune cells. METHODS: The ability of C. concisus, Campylobacter showae, Campylobacter hominis, and Bacteroides ureolyticus to invade epithelial cells was examined using scanning electron microscopy and gentamicin protection assays. Proinflammatory cytokines generated by epithelial and immune cells in response to these bacteria were determined by enzyme-linked immunosorbent assay. Ussing Chamber, immunofluorescent stain, and Western blot were used to further elucidate the impact of C. concisus on intestinal barrier integrity and functions. RESULTS: Attachment of non-C. jejuni Campylobacter species to Caco-2 or HT-29 cells was mediated by flagellum-dependent and/or -independent processes. C. concisus was able to invade Caco-2 cells, generate a membrane-ruffling effect on the epithelial surface on entry, and damage epithelial barrier functions by preferential attachment to the cell-cell junctions. Proinflammatory cytokine profiles exhibited by epithelial cells, monocytes, and macrophages in response to C. concisus and other non-C. jejuni Campylobacter species were species and strain specific. CONCLUSIONS: These findings demonstrate that C. concisus and other non-C. jejuni Campylobacter species may play a role in initiating gastrointestinal diseases.

An efficient and aseptic preparation of "sodium fluoride ((18)F) injection" in a GMP compliant facility.

INTRODUCTION: "Sodium fluoride ((18)F) injection" is an isotonic NaCl solution containing [(18)F]NaF to be used as bone imaging agent. Although its NDA was approved by the US FDA in 1972, it has not been commercially available since 1975 due to mostly the popularity of (99m)Tc-MDP. Recently, advances in PET/CT technology and the often interrupted (99m)Tc supply have led to the renewed interest in the use of [(18)F]NaF to detect bone metastases in cancer patients. This report introduces an efficient, low-cost and aseptic preparation of "Sodium fluoride ((18)F) injection" for PET scan. METHOD: (18)F-Fluoride in target water from cyclotron was adsorbed onto four different forms of anion-exchange resins then desorbed by isotonic NaCl solution into the product vial. One of the resins that yielded the product at the suitable pH was used for the aseptic preparation. The components for this setup, including stopcocks, extension tubes, etc., were all single-use, individually packed and sterile. The process was done in a lead-line isolator maintained in grade A (PIC/S) aseptic condition. The quality of the obtained "Sodium fluoride ((18)F) injection" was analyzed according to its monograph in the European Pharmacopoeia (EP). RESULTS: The resin in the chloride form yielded the product of pH 6.7 and was chosen for the subsequent preparation. The radiochemical yield was quantitative. The product met all criteria specified in EP, including biological, physical and chemical specifications. CONCLUSIONS: This method is an efficient, space-saving and extremely low-cost operation that easily performed in an aseptic environment meeting GMP standard. The quality of the "Sodium fluoride ((18)F) injection" so yielded meets EP specifications. This setup provides hospital with facility meeting GMP standard a cost effective and efficient method for "Sodium fluoride ((18)F) injection" production without the need for the expensive automatic module and extra QC instrument.

Kimura's disease with generalized lymphadenopathy demonstrated by positron emission tomography scan.

Kimura's disease is a chronic inflammatory disorder that occurs mainly in Asian patients. Most imaging studies focus on the loco-regional involvement of this disorder. Images of the whole body fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) scan have not been reported in the literature before. The possibility of lymphoid clonality is also discussed frequently despite its clinically benign course. We present a patient of Kimura's disease initially assessed by whole body 18F-FDG PET study and proved by pathologic findings. 18F-FDG-PET scan showed diffusely intense uptake in the neck, axillary, pelvic and inguinal nodal regions bilaterally, as well as in the mediastinal, celiac region. The flow cytometric analysis of lymph node tissue confirmed the absence of clonality. The image of 18F-FDG-PET in Kimura's disease can closely resemble that seen in neoplastic disorders such as lymphoma or metastatic lymphadenopathy. It should be taken into consideration as a differential diagnosis for a generalized lymphadenopathy.

Fluoro-, bromo-, and iodopaclitaxel derivatives: synthesis and biological evaluation.

Paclitaxel (Taxol) is a clinically important chemotherapeutic agent. We describe the synthesis of fluoro-, bromo-, and iodopaclitaxel and their [(18)F]fluoro-, [(76)Br]bromo-, and [(124)I]iodo- analogues. [(18)F]Fluoropaclitaxel shows high uptake and rapid clearance from tissues in rats. Preadministration of paclitaxel in normal rats significantly increases (p < 0.005) retention of [(18)F]fluoropaclitaxel and [(76)Br]bromopaclitaxel in blood (33.0%), heart (32.0%), lung (37.6%) kidney (142.4%); and blood (33.4%), lung (42.3%), kidney (62.4%), respectively. [(18)F]Fluoropaclitaxel uptake in the brain of mdr1a/1b(-/-) mice is increased 1400% (p < 1.3e-07) relative to wild-type controls. Preadministration of paclitaxel or XR9576, a modulator, had little effect on the biodistribution in these mdr1a/1b(-/-) mice. As a result, [(18)F]fluoropaclitaxel will be a useful radiopharmaceutical for the study of multidrug resistant tumors.

Improved renal clearance and tumor targeting of 99mTc-labeled anti-Tac monoclonal antibody Fab by chemical modifications.

This study was undertaken to improve the renal clearance and tumor targeting properties of 99mTc-labeled humanized anti-Tac (HuTac) monoclonal antibody Fab fragments using two chemical approaches: 1) labeling with a renal secretion agent 99mTc-mercaptoacetyltriglycine (MAG3) and 2) lowering its isoelectric point (pI) by acylation. HuTac Fab (3.3 mg/mL) was reacted with a trifluorophenyl ester (TFP) of 99mTc-MAG3 alone or was additionally reacted with TFP-glycolate to reduce the pI. In Balb/c mice, 99mTc-MAG3-Fab (pI > 9.3) rapidly accumulated in the kidneys (177% injected dose [ID]/g at 15 min) and then gradually cleared out of the kidneys. In contrast, the glycolation (pI 4.6 approximately 6.6) drastically reduced the renal uptake (31% ID/g) and also the whole-body retention (82% ID vs 101% for the nonglycolated) at 15 min, indicating that the glycolated 99mTc-MAG3-Fab (pI 4.6 approximately 6.6) was rapidly excreted. The glycolated remained in the blood longer than the nonglycolated (1.2% vs 0.3% ID/g at 360 min), but this effect was less drastic than the effect shown on the renal uptake. In nude mice bearing receptor-positive (ATAC4) tumors, the glycolated 99mTc-MAG3-Fab increased the peak tumor uptake to 14.8% ID/g from 8.3% ID/g for 99mTc-MAG3-Fab, whereas the glycolation resulted in a drastic reduction of the renal uptake at 15 min. We demonstrated that the renal clearance and the tumor targeting of Fab could be optimized by chemical modifications.

Differences in sensitivity of biological functions mediated by epidermal growth factor receptor activation with respect to endogenous and exogenous ligands.

Despite constitutive expression of autocrine transforming growth factor-alpha (TGF-alpha) in growth factor-independent colon carcinoma cells, the epidermal growth factor receptor (EGFr) is not saturated and can be further activated by exogenous EGFr ligand. Given that the activation of EGFr by exogenous growth factor has no further effect on DNA synthesis, the question arises as to what function this additional EGFr activation might have. We report that EGF induces integrin alpha2 expression, integrin-mediated adhesion, and micromotility of HCT116 cells. The stimulatory effect of ligand on these biological functions is abrogated by treatment with AG1478- and EGFr-blocking monoclonal antibody. This provides evidence that the biological responses are EGFr-mediated and EGFr is located upstream of integrin alpha2 expression. Therefore, although exogenous EGF has no effect on DNA synthesis beyond that induced by autocrine TGF-alpha (at subsaturating levels of EGFr occupation) exogenous growth factor does induce integrin alpha2 expression, cell adhesion, and micromotion. An important finding revealed by this study is the documentation of biological responses of EGFr-mediated functions, including DNA synthesis, cell adhesion, and micromotion, which differ in sensitivity with respect to different degrees of EGFr activation at the basal state and in response to exogenous ligand.