Abstract P5-04-30: Developing an immunohistochemistry protocol to detect neurofibromin as an effective, simple, and rapid method to identify NF1-negative breast cancer patients

Background:Neurofibromin is a key tumor suppressor, well-known as a GTPase-Activating-Protein (GAP) to attenuate Ras signaling. It is encoded by the NF1gene, so named because its inactivation was first discovered to cause Neurofibromatosis type 1, an autosomal dominant genetic disorder. We have recently reported thatnonsense (NS) and frameshift (FS) mutations, but not missense mutations, in NF1are associated with a markedly higher risk of relapse and death in early stage ER+breast cancer after adjuvant tamoxifen monotherapy (Griffith et al. in press). Surprisingly, despite being best known as a GAP, no missense mutations inactivating NF1's GAP activity were found in our cohort. We have evidence that these NF1NS/FS mutations cause the resulting mRNAs to be degraded, leading to depletion of the entire NF1 protein. In a separate study that was presented here last year, we showed that NF1 is also an ER co-repressor, which partially explains why the loss of the single tumor suppressor NF1 is so detrimental — because this turns on two potent oncogenic pathways. Thus far there is no effective means to assess loss of NF1 protein in cancer. The objective of this project is to identify these aggressive NF1-negative breast cancers by establishing an immunohistochemistry (IHC) protocol with a valid NF1 antibody in order to properly find and treat them in the future.

Methods:A monoclonal antibody was raised against the C-terminus of NF1. Immunostaining as well as IHC was performed using a set of breast cancer cell lines with varying degrees of NF1 protein levels, including several NF1 null-like cell lines as negative controls. To assess whether the IHC protocol can be used on patients, NF1+and NF1–PDXs as well as patient biopsies were examined.

Results: We have purified a monoclonal antibody against NF1 (m376). By immunostaining, a strong NF1 signal can be seen in T47D cells, which have four copies of the NF1gene. In contrast, there was barely any signal in MDA-MB-175VII cells, which lack detectable NF1 due to NF1FS mutations. While NF1 appears mostly cytoplasmic, 10-15% can be seen in the nucleus. Nuclear NF1 levels can be further increased by the nuclear export blocker leptomycin-B, suggesting that NF1 is shuttled in and out of the nucleus. IHC staining confirmed these features of NF1. In addition, a weak nuclear signal can be seen in cancer cells carrying NF1FS mutations. Experiments are on-going to assess how to analyze tumor samples for NF1 loss and whether NF1FS mutations cause expression of truncated proteins that are nuclear.

Conclusion: Our results suggest that the m376 antibody has the potential to be used for IHC, provided that samples known to be NF1+or NF1–are included as controls. The success of this project will have particular clinical impact in telling us who should notbe treated by tamoxifen. Furthermore, we have an approved clinical trial protocol to assess the concept that these NF1–patients should instead be treated by combining a Ras pathway inhibitor and a SERD.

Citation Format: Peng J, Zheng Z-y, Cakar B, Li J, Singh P, Szafrain AT, Stossi F, Dubrulle J, Mancini MA, Mao R, Miles G, Ellis MJ, Chang EC. Developing an immunohistochemistry protocol to detect neurofibromin as an effective, simple, and rapid method to identify NF1-negative breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-30.

[ORAI1 variation induced combined immunodeficiency: a case report and literature review]

Objective: To summarize the clinical manifestations and gene variations of combined immunodeficiency caused by ORAI1 variation with a case report and literature review. Methods: The clinical data of the patient who was diagnosed with ORAI1 variation caused combined immunodeficiency in the Department of Pediatrics in Xiangya Hospital of Central South University in February 2018 were extracted and analyzed. The literature till August 2018 was searched with key words of 'ORAI1', and 'immunodeficiency' in both English and Chinese in the database of China national knowledge infrast ructure (CNKI), Wanfang and Pubmed. Results: The patient was a 15 months old girl with acute onset of bilateral ptosis after upper respiratory tract infection, which was rapidly progressed to systemic myasthenia and accompanied with recurrent respiratory tract infection during the treatment. The patient poorly to responded immunomodulatory therapy and anti-infection therapy. Laboratory tests demonstrated decreased complement C3 and NK cell (CD3(-)CD56(+)), increased anti-thyroglobulin, thyroid peroxidase antibody and B lymphocyte (CD3(-)CD19(+)), and slightly increased anti-acetylcholine receptor antibody. Genetic analysis showed the homozygous variation of ORAI1 gene exon l c.12 G>T (p.E4D), with heterozygostty of both parents. There were only 4 papers reporting this disease in the literature review. A total of 7 patients with ORAI1 gene variation were reported, including 3 homozygous variations, 2 heterozygous variations and 2 complex heterozygous variations. The clinical manifestations included early onset recurrent infection, congenital hypotonia, elevated serum IgA and IgM, decreased NK cells, and family history of hereditary diseases. Four of the 7 reported cases died of pulmonary infection and sepsis, and the other 3 survived with low muscular tone and poor self-care ability. Conclusions: The most common clinical manifestations of ORAI1 variation caused combined immunodeficiency are recurrent infection and congenital hypotonia. Myasthenia induced recurrent respiratory tract infection is an important factor of poor prognosis in severe patients. There is a lack of effective treatment for this disease, and the prognosis is poor.

A Simple and Reliable Cooling Approach for the Cryopreservation of Hematopoietic Stem Cells: the Passive Cooling Rate-controlled Technique

BACKGROUND

Cryopreservation of hematopoietic stem cells (HSCs) has widely been used in stem cell transplantation and cellular therapy treating various human diseases. However, the current conventional cooling approach for the cryopreservation of HSCs has the following potential problems: (1) requirement of a very expensive computer-programmed liquid nitrogen freezer (LNF) for the cooling rate control, (2) a large consumption of liquid nitrogen, (3) periodic breakdown of the LNF due to the mechanical failure of the liquid nitrogen valves (i.e., magnetic-solenoid valves) inside the LNF, and (4) constant monitoring of the LNF operation during the HSCs cooling process.

OBJECTIVE

To test and evaluate a simple and reliable approach for the cryopreservation of HSCs using the passive cooling technique.

MATERIALS AND METHODS

A passive cooling-rate-controlled device (PCD) was developed and used to cryopreserve HSCs. The PCD is inexpensive, simple, and user-friendly, which needs only the minimum maintenance and no consumption of liquid nitrogen. The PCD was compared to the LNF for the cryopreservation of HSCs in the present study through experiments. The cell viability and functionality were evaluated after cryopreservation.

RESULTS

In comparison with the LNF method, the PCD approach enabled high cell viability/survival, recovery rate, and functionality after cryopreservation processes.

CONCLUSION

The PCD offers a cost-effective, simple, and reliable approach for the optimal cryopreservation of HSCs.

Management of acute Achilles tendon ruptures: A review

Objectives

The incidence of acute Achilles tendon rupture appears to be increasing. The aim of this study was to summarize various therapies for acute Achilles tendon rupture and discuss their relative merits.

Methods

A PubMed search about the management of acute Achilles tendon rupture was performed. The search was open for original manuscripts and review papers limited to publication from January 2006 to July 2017. A total of 489 papers were identified initially and finally 323 articles were suitable for this review.

Results

The treatments of acute Achilles tendon rupture include operative and nonoperative treatments. Operative treatments mainly consist of open repair, percutaneous repair, mini-open repair, and augmentative repair. Traditional open repair has lower re-rupture rates with higher risks of complications. Percutaneous repair and mini-open repair show similar re-rupture rates but lower overall complication rates when compared with open repair. Percutaneous repair requires vigilance against nerve damage. Functional rehabilitation combining protected weight-bearing and early controlled motion can effectively reduce re-rupture rates with satisfactory outcomes. Biological adjuncts help accelerating tendon healing by adhering rupture ends or releasing highly complex pools of signalling factors.

Conclusion

The optimum treatment for complete rupture remains controversial. Both mini-open repair and functional protocols are attractive alternatives, while biotherapy is a potential future development.

Cite this article: X. Yang, H. Meng, Q. Quan, J. Peng, S. Lu, A. Wang. Management of acute Achilles tendon ruptures: A review. Bone Joint Res 2018;7:561–569. DOI: 10.1302/2046-3758.710.BJR-2018-0004.R2.

[A family with Allan-Herndon-Dudley syndrome due to SLC16A2 gene mutation]

Objective: To report a family diagnosed with Allan-Herndon-Dudley syndrome (AHDS) due to SLC16A2 gene mutation and to summarize the phenotypes, genotypes, diagnosis, treatment, and prognosis. Methods: The clinical features of a family of AHDS diagnosed in Xiangya Hospital of Central South University in November 2017 were analyzed. Related literature was searched at Online Mendelian Inheritance in Man (OMIM), PubMed, CNKI and Wanfang database (from the establishment of databases to June 2018) by using "Allan-Herndon-Dudley syndrome" , and "AHDS" as keywords and the case reports from April 2013 to June 2018 were reviewed. Results: The proband was a boy aged 8 months who presented with global developmental retardation, inability to hold up the head, disability to sit independently or grab, no language development, elongated face, big ears, esotropia, scoliosis, hypotonia in the trunk, hypertonia in extremities, and hyperreflexia. Brain magnetic resonance imaging (MRI) showed widening of the extracerebral space and delayed myelination. Thyroid function tests revealed increased FT3, decreased FT4 and normal TSH. Whole exome sequencing (WES) revealed the SLC16A2 gene c.431-1 (IVS1) G>C hemizygous mutation. The infant's mother and grandmother are carriers, but whose father had no related mutation. One uncle from maternal side had severe psychomotor retardation as well as dystonia and died at one year of age with unknown etiology. A total of 97 articles were retrieved in which 19 case reports were reviewed. Forty-two cases (22 from 8 families and 20 sporadic) were reported. Among these 42 cases (all males), all of them presented with moderate to severe cognitive dysfunction, 15 with seizures; 36 were bedridden, only 4 could walk; 31 had no language development, 2 could speak sentences, 4 could speak few words, 1 had babbling sounds. Furthermore,16 had microcephaly, 18 had facial dysmorphism, 6 had esotropia, 2 had hearing loss,14 had scoliosis, 11 had joint contracture, 30 had low body weight/muscle wasting, 37 had hypotonia in trunk or extremities, 32 had progressive spastic paraplegia or hypertonia. In terms of thyroid function, 33 had abnormal results, within whom 30 had increased T3, 25 had decreased T4 and 3 had increased TSH. Brain MRI showed delayed myelination in 22 cases, within which one normalized with development. Genetic tests showed that 31 had missense mutation (14 sporadic), 5 had deletion mutation (3 sporadic, and 1 due to frameshift mutation), 5 had insertion mutation (2 sporadic), and 1 had repeated mutation. The prognosis was poor as patients often died of recurrent respiratory tract infection. Conclusions: The main clinical manifestations of AHDS are severe global developmental retardation, hypotonia, spastic paraplegia, abnormal serum levels of thyroid hormone and delayed brain myelination. SLC16A2 c. 431-1 (IVS1) G > C mutation is accountable for this disease.

[Guidelines for diagnosis and treatment of dengue in China]

Dengue is the most prevalent and rapidly spreading mosquito-borne viral disease. As a dengue non-endemic country, China has experienced several dengue outbreaks in recent years. However, dengue patients in China displayed distinct clinical characteristics compared to patients in endemic countries. To standardize the diagnosis and treatment of dengue fever, the experts of the Society of Infectious Diseases, Society of Tropical Medicine and Parasitology of Chinese Medical Association, and the Society of Emergency Medicine, China Association of Chinese Medicine have reached this guideline based on guidelines for diagnosis, treatment, prevention and control of dengue (World Health Organization, 2009); guidelines for diagnosis and treatment of dengue (National Health and Family Planning Commission of the People's Republic of China, 2014, Edition 2), health industry standard of the People's Republic of China "diagnosis for dengue fever (WS216-2018)" and systemic reports on dengue. The guideline includes 8 aspects: introduction, terminology, epidemiology and prevention, etiology and pathogenesis, clinical features, diagnosis, treatment and problems to be solved.