Glutamine-linked and non-consensus asparagine-linked oligosaccharides present in human recombinant antibodies define novel protein glycosylation motifs

We report the presence of oligosaccharide structures on a glutamine residue present in the V(L) domain sequence of a recombinant human IgG2 molecule. Residue Gln-106, present in the QGT sequence following the rule of an asparagine-linked consensus motif, was modified with biantennary fucosylated oligosaccharide structures. In addition to the glycosylated glutamine, analysis of a lectin-enriched antibody population showed that 4 asparagine residues: heavy chain Asn-162, Asn-360, and light chain Asn-164, both of which are present in the IgG1 and IgG2 constant domain sequences, and Asn-35, which was present in CDR(L)1, were also modified with oligosaccharide structures at low levels. The primary sequences around these modified residues do not adhere to the N-linked consensus sequon, NX(S/T). Modeling of these residues from known antibody crystal structures and sequence homology comparison indicates that non-consensus glycosylation occurs on Asn residues in the context of a reverse consensus motif (S/T)XN located on highly flexile turns within 3 residues of a conformational change. Taken together our results indicate that protein glycosylation is governed by more diversified requirements than previously appreciated.

Role for cathepsin K in emphysema in smoke-exposed guinea pigs

The protease-antiprotease imbalance in the lung plays an important role in the pathogenesis of smoke-induced emphysema. The aim of this study was to characterize the proteolytic responses leading to emphysema formation in the guinea pig smoke exposure model. Guinea pigs were exposed to cigarette smoke for 1, 2, 4, 8, and 12 weeks. Age-matched guinea pigs exposed to room air served as controls. Cigarette smoke induced inflammation after 4 weeks and generated emphysematous changes in the guinea pigs after 12 weeks of smoke exposure. Increased phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) mitogen-activated protein (MAP) kinases was demonstrated post cigarette smoke exposure. A decrease in elastin and collagen and the loss of type III collagen were observed in the alveolar wall of smoke-exposed guinea pigs. Interestingly, no change was seen in the expression of collagenolytic matrix metalloproteinases. Furthermore, the authors observed a 3-fold increase in cathepsin K activity in the lungs of smoke-exposed guinea pigs. The significance of this finding was supported by human studies that demonstrate increased expression of cathepsin K in the lungs of patients with emphysema. Elevation of cathepsin K in guinea pig lungs after smoke exposure likely constitutes a critical event leading to the disruption of lung extracellular matrix in this model.

Prevalence of BRCA1/2 Mutations and Variants in a Southwest Hispanic Population

Background: There have been a limited number of studies of BRCA mutations in U.S. Hispanics. Of those previously published, two common mutations have been identified, and estimates of their prevalence vary, depending on the population studied. North American Hispanics are a heterogeneous population, consisting of Mexican, Caribbean, Central and South American descent. Furthermore, each of these groups has a significant admixture of other racial and ethnic groups. A limitation of most published studies is that they do not differentiate between these ethnically and genetically diverse Hispanics. In New Mexico, there is a large but relatively homogeneous Hispanic population. Since the University of New Mexico Cancer Center (UNMCC), sees a socially and economically diverse group of patients, the demographics of its Hispanic patients are similar to those of the whole state. Herein, we describe the prevalence of specific mutations and variants in Hispanics from a clinic-based population.Materials and Methods: A chart review of all patients evaluated for hereditary breast cancer risk from 1/1/2005 through 5/30/2009 was conducted. Data collected included patient age, self-reported ethnicity (including, if known, area of ancestral origin), cancer status, family history, BRCA testing status, including method (comprehensive analysis, Ashkenazi panel, single site, and/or comprehensive rearrangement testing), and what, if any, BRCA mutations or variants were found.Results: BRCA testing was performed on 312 patients, 70 of whom identified as NM Hispanic. Another 24 patients were of other Hispanic origins, mainly Mexican. Approximately 30% of those identified as NM Hispanic tested positive for mutations, and most mutations were found in BRCA1. All variants of uncertain significance in this group were found in BRCA2. Approximately 20% of other Hispanics tested positive for mutations, but variants of uncertain significance comprised a higher percentage of the results. In New Mexican Hispanics, 47% tested positive for BRCA1 187delAG, and another 19% tested positive for BRCA1 deletion of exons 9-12, both of which are previously described in the Hispanic populations from southern California and Colorado.Discussion: Although we found a large proportion of previously described mutations in our Hispanic population, 34% had other mutations. In this group, no mutation was seen more than once, indicating the need to offer these patients comprehensive BRCA testing or a combination of founder mutations testing followed by comprehensive sequencing. As most of our patients, even those identified as “Other Hispanic” have Colonial Spanish origins (via Mexico), this data is likely not applicable to Hispanics with other admixtures or historic arrival in the New World, such as Hispanics from the Caribbean.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4077.

Asparagine-linked oligosaccharides present on a non-consensus amino acid sequence in the CH1 domain of human antibodies

We report that N-linked oligosaccharide structures can be present on an asparagine residue not adhering to the consensus site motif NX(S/T), where X is not proline, described in the literature. We have observed oligosaccharides on a non-consensus asparaginyl residue in the C(H)1 constant domain of IgG1 and IgG2 antibodies. The initial findings were obtained from characterization of charge variant populations evident in a recombinant human antibody of the IgG2 subclass. HPLC-MS results indicated that cation-exchange chromatography acidic variant populations were enriched in antibody with a second glycosylation site, in addition to the well documented canonical glycosylation site located in the C(H)2 domain. Subsequent tryptic and chymotryptic peptide map data indicated that the second glycosylation site was associated with the amino acid sequence TVSWN(162)SGAL in the C(H)1 domain of the antibody. This highly atypical modification is present at levels of 0.5-2.0% on most of the recombinant antibodies that have been tested and has also been observed in IgG1 antibodies derived from human donors. Site-directed mutagenesis of the C(H)1 domain sequence in a recombinant-human IgG1 antibody resulted in an increase in non-consensus glycosylation to 3.15%, a greater than 4-fold increase over the level observed in the wild type, by changing the -1 and +1 amino acids relative to the asparagine residue at position 162. We believe that further understanding of the phenomenon of non-consensus glycosylation can be used to gain fundamental insights into the fidelity of the cellular glycosylation machinery.

Improved outcomes in advanced stage uterine carcinosarcoma (mixed mullerian tumor [MMT])

5518

Background: There is currently no consensus regarding the management of advanced stage uterine MMT. In an effort to better define postoperative treatment modalities and their associated outcomes, we retrospectively reviewed factors that influence progression and survival. Methods: A retrospective, multi-institution study of women diagnosed from 1997–2007 was performed. Post-operative treatment included either observation (OBS), RT (brachytherapy, whole pelvic, or combination), chemotherapy (CT) alone or with RT (CT+RT). The majority of chemotherapy regimens included carboplatinum/paclitaxel, Ifosfamide/cisplatin, cisplatin/adriamycin, Data collected included time to recurrence, overall survival and sites of recurrence. Statistics included t-test, ANOVA and Kaplan Meier. Results: 119 patients were identified with late stage uterine MMT. 81 had stage III disease and 38 had stage IV disease. The median age at diagnosis was 67 years (range: 30–86). 70 (59%) were Caucasian and 48 (40%) were African-American. 116 (87%) were optimally debulked and their survival further analyzed. 18 (15%) were observed and 9 of these patients recurred. This group had the poorest median progression free survival (PFS) of 3.4 months. The majority (N = 50, 49%) of late stage patients underwent adjuvant CT with a median PFS of 13.3 months and median OS of 15.6 months. Of these patients 33 (66%) recurred. 18 (17 %) patients underwent RT alone with a median PFS of 12.4 months and OS of 14.9 months. 14 (78%) of these patients recurred. 20 patients (19%) underwent a combination of CT and RT and 11 (55%) experienced recurrences . The combination therapy group had the longest median PFS of 14.3 months and OS of 17.2 months (p = 0.27). Conclusions: Chemotherapy had become the standard therapy for advanced stage MMT however the addition of radiation has not been established. Patients diagnosed with advanced stage MMT can achieve long-term DFS in a minority of patients (33%) treated with chemotherapy. We showed that the addition of radiation to adjuvant chemotherapy showed a slight improvement over chemotherapy alone yet the optimal therapy has yet to be defined. This retrospective review highlights the need for prospective trials of new therapeutic agents and treatment regimens for women with advanced stage uterine MMT.

No significant financial relationships to disclose.

Effect of treatment of patients with early-stage uterine carcinosarcoma

5516

Background: The treatment of early stage uterine carcinosarcoma is controversial. We sought to retrospectively review factors that influence progression and survival. Methods: A retrospective, multi-institution study of women diagnosed from 1997–2007 was performed. Postoperative treatment included either observation (OBS), RT (brachytherapy, whole pelvic, or combination), chemotherapy (CT) alone or with RT (CT+RT). Data collected included time to recurrence, overall survival, and sites of recurrence. Statistics included ANOVA and Kaplan Meier. Results: One hundred and forty-six patients were diagnosed with early stage (stages 1 and 2) uterine carcinocarcoma. The median age at diagnosis was 68 years (range:40–91). The majority (62%) were Caucasian, 49 (34%) were African-American and the remainder were other ethnicities. One hundred and seventeen had stage 1 disease and 29 had stage 2. The majority of patients (N = 54, 37 %) were observed, 36 (25%) were treated with CT, 31 (21%) were treated with RT and 17 (12%) were treated with CT + RT. The median progression free survival (PFS) for patients diagnosed with early stage disease was 16.7 months for the OBS cohort and 38.2 months for the CT cohort (p < 0.01). Median overall survival was 23 months for the OBS cohort and 39.3 months for the CT cohort (p = 0.02). The cohorts that underwent RT or CT+RT had improved median progression free (29.9, 20 months) and overall survival (31.7, 20.8 months) as compared to the OBS cohort, however this was not a statistically significant difference. Conclusions: We report on the largest experience in the literature on early stage uterine carcinosarcoma and the first to show that women with early stage disease may benefit from adjuvant chemotherapy. The role of radiation therapy or combination chemotherapy and radiation could not be adequately assessed from this retrospective analysis, but a trend toward improved survival was present. Prospective trials evaluating the best treatment for patients with early stage carcinosarcoma of the uterus should be undertaken to better answer this question.

No significant financial relationships to disclose.

Paravertebral block for breast surgery: a cost analysis

Abstract #6103

Background: Paravertebral block (PVB) is a form of regional block that has long been used in surgical procedures, including breast surgery. PVB provides intraoperative and postoperative analgesia, decreasing the need for narcotics (NA). It also decreases amounts of general anesthesia (GA) required. NA and GA contribute to postoperative nausea and vomiting, which is decreased with PVB. There has not been a modern cost analysis of PVB in breast surgery. The purpose of this study is to evaluate patient comfort and cost effectivness of PVB in breast surgery.&#x2028; Materials and Methods: A retrospective chart review of 461 breast cases was performed. Mastectomy with or without axillary staging and lumpectomy with axillary staging were included (n=188). Minor breast biopsies, lumpectomies alone, and combined reconstructions/other procedures were excluded. Data collected included whether or not PVB was performed (based on surgeon/patient/anesthesiologist preference), length of stay (LOS), postoperative requirements for NA and antiemetics (AE), and complications from PVB. Patients (pts) were scheduled as inpatient (IP) or outpatient (OP) based on procedure and comorbidities. The data was analyzed for IP and OP groups for LOS. Cost was calculated from NA and AE use and overnight stay.&#x2028; Results: 188 total procedures (125 IP; 63 OP). 88/125 IP had PVB (70%). 57/63 OP had PVB (90%). IP LOS &lt; 24 hrs had 4/5 with PVB (80%); 1/5 without (20%). LOS 24-36 hrs had 46/63 with PVB (73%); 17/63 without (27%). 57 had LOS &gt; 36 hrs; 38/57 with PVB (67%); 19/57 without (33%). OP LOS 0-2 hrs had 41 pts; 39/41 with PVB (95%); 2/41 without (5%). 22 had LOS &gt; 2 hrs; 18/22 with PVB (82%); 4/22 without (18%). There was an overall shorter LOS for both IP and OP with PVB than without (p=0.0151). 152/188 pts required NA (81%). 112/152 received PVB (74%); 40/152 did not (26%). 36/188 did not require NA (19%). 32/36 received PVB (89%); 4/36 did not (11%). There was a difference between those who did and did not receive PVB and NA use (p=0.0257). 86/188 required antiemetics (46%). 59/86 received PVB (69%); 27/86 did not (31%). 102/188 did not require AE (54%). 86/102 received PVB (84%); 16/102 did not (16%). There was a difference between those who did and did not receive PVB and requirements for AE (p=0.0143). Number of doses of NA and AE were summarized as cost values per pt. The average cost for these medications for an IP with PVB was $184 vs $213 without. OP medicine costs with and without PVB was $39 and $111. Overall average cost difference was $29 for IP, $72 for OP. OP also saved $800 overnight charge. For all pts combined, there was a statistical cost difference (p=0.0085). 1/188 pts had a complication (pneumothorax).&#x2028; Discussion: PVB results in less use of postoperative NA and AE in breast surgery. Not only is this reflected in pt comfort, but also a statistically significant cost reduction for both IP and OP procedures and LOS.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6103.

Integration of immunization services with other health interventions in the developing world: what works and why? Systematic literature review

OBJECTIVE

To assess benefits, challenges and characteristics of integrating child and maternal health services with immunization programmes.

METHODS

Literature review using journal databases and grey literature. Papers meeting the inclusion criteria were rated for the quality of methodology and relevant information was systematically abstracted.

RESULTS

Integrated services were vitamin A supplementation, bednet distribution, deworming tablet distribution, Intermittent Preventive Therapy for infants and referrals for family planning services. Two key characteristics of success were compatibility between interventions and presence of a strong immunization service prior to integration. Overburdened staff, unequal resource allocation and logistical difficulties were mentioned as risks of integration, whereas rapid uptake of the linked intervention and less competition for resources were listed as two key benefits of integration.

CONCLUSION

The theoretical strengths of integrating other health services with immunization services remain to be rigorously proved in practice. When additional interventions are carefully selected for compatibility and when they receive adequate support, coverage of these interventions may improve, provided immunization coverage is already high. Evidence for the effectiveness of integration in increasing efficiency of resource use was insufficient and most benefits and challenges were not statistically quantified. More substantive information about the costs of integrated vs. vertical programmes and full documentation of the impacts of integration on immunization services should be published.

Transgenic expression of matrix metalloproteinase-9 causes adult-onset emphysema in mice associated with the loss of alveolar elastin

Matrix metalloproteinase (MMP)-9 has been consistently identified in the lungs of patients with chronic obstructive pulmonary disease (COPD). However, its role in the development of the disease remains undefined. Mice that specifically express human MMP-9 in their macrophages were generated, and morphometric, biochemical, and histological analyses were conducted on the transgenic and littermate control mice over 1 yr to determine the effect of macrophage MMP-9 expression on emphysema formation and lung matrix content. Lung morphometry was normal in transgenic mice at 2 mo of age (mean linear intercept = 50+/-3 littermate mice vs. 51+/-2 transgenic mice). However, after 12 mo of age, the MMP-9 transgenic mice developed significant air space enlargement (mean linear intercept = 53+/-3 littermate mice vs. 61+/-2 MMP-9 transgenic mice; P<0.04). Lung hydroxyproline content was not significantly different between wild-type and transgenic mice, but MMP-9 did significantly decrease alveolar wall elastin at 1 yr of age (4.9+/-0.3% area of alveolar wall in the littermate mice vs. 3.3+/-0.3% area of alveolar wall in the MMP-9 mice; P<0.004). Thus these results establish a central role for MMP-9 in the pathogenesis of this disease by demonstrating that expression of this protease in macrophages can alter the extracellular matrix and induce progressive air space enlargement in mice.

Probability of BRCA1/2 mutation varies with ovarian histology: results from screening 442 ovarian cancer families

While there are many reports in the literature of mutation testing of BRCA1 and BRCA2 in breast/ovarian cancer families, the question of which type of ovarian cancers are relevant still pertains. We have undertaken whole gene screening including multiple ligation-dependent probe amplification in an affected individual within 442 unrelated non-Jewish families containing at least one reported ovarian cancer diagnosed less than 50 years or at any age with family history of breast or ovarian cancer for mutations in BRCA1 and BRCA2. A total of 166 mutations were identified 110 (25%) in BRCA1 and 56 (13%) in BRCA2. In families without confirmation of ovarian diagnosis, the detection rate drops significantly. In families fulfilling Breast Cancer Linkage Consortium (BCLC) criteria with confirmed ovarian cancer cases, the mutation detection frequency was 80%. If only BCLC families with unconfirmed ovarian cancers were included, the detection rate dropped to 36% when a relevant ovarian cancer diagnosis was not confirmed. In BCLC families containing only one ovarian cancer, BRCA2 accounted for 45% of identified mutations. No mutations were identified in affected individuals with borderline or mucinous tumours. Detection rates dropped below the 10/20% international thresholds in a number of families with unconfirmed ovarian cancers. Borderline/mucinous pathology substantially reduces the likelihood of identifying a BRCA1/2 mutation. Strenuous efforts should be made to confirm ovarian pathology if the lack of confirmation or refuting the diagnosis would decrease a family's likelihood of mutation detection below screening thresholds. In the UK, a higher proportion of families harbour BRCA2 pathogenic mutations than predicted from previous studies.

Molecular characterisation of SMARCB1 and NF2 in familial and sporadic schwannomatosis

BACKGROUND

Schwannomatosis is a rare condition characterised by multiple schwannomas and lack of involvement of the vestibular nerve. A recent report identified bi-allelic mutations in the SMARCB1/INI1 gene in a single family with schwannomatosis. We aimed to establish the contribution of the SMARCB1 and the NF2 genes to sporadic and familial schwannomatosis in our cohort.

METHODS

We performed DNA sequence and dosage analysis of SMARCB1 and NF2 in 28 sporadic cases and 15 families with schwannomatosis.

RESULTS

We identified germline mutations in SMARCB1 in 5 of 15 (33.3%) families with schwannomatosis and 2 of 28 (7.1%) individuals with sporadic schwannomatosis. In all individuals with a germline mutation in SMARCB1 in whom tumour tissue was available, we detected a second hit with loss of SMARCB1. In addition, in all affected individuals with SMARCB1 mutations and available tumour tissue, we detected bi-allelic somatic inactivation of the NF2 gene. SMARCB1 mutations were associated with a higher number of spinal tumours in patients with a positive family history (p = 0.004).

CONCLUSION

In contrast to the recent report where no NF2 mutations were identified in a schwannomatosis family with SMARCB1 mutations, in our cohort, a four hit model with mutations in both SMARCB1 and NF2 define a subset of patients with schwannomatosis.