Rosai-Dorfman disease with lung involvement in a 10-year-old patient: A case report.

BACKGROUND: Rosai-Dorfman disease (RDD) is a rare benign proliferative disease whose etiology is not clear and may be related to infection or unexplained immune dysfunction. The authors present a case of RDD with lung involvement in a 10-year-old patient. CASE SUMMARY: A 10-year-old girl found that her left cervical lymph nodes were enlarged for more than 7 mo, and the largest range was about 6.5 cm × 5.9 cm × 8.1 cm. Cervical magnetic resonance imaging showed multiple masses in the left neck, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. A malignant tumor, with a high possibility of lymph node metastasis, was initially considered. At the same time, lung computed tomography showed multiple nodules of different sizes scattered on both sides of the lung, with uniform internal density. Thus, a possible metastatic tumor was considered. Finally, RDD was diagnosed by pathology and immunohistochemistry. According to the antibiogram, clindamycin was administered for 2 wk, and prednisone acetate was administered for 7 wk. Nine months later, the ulcer in the left neck was better than before, but the imaging showed that the lesion was not controlled. CONCLUSION: The diagnosis of RDD cannot be made by a single tool and its treatment is a long-term exploratory process. Follow-up is necessary.

Laryngopharyngeal reflux disease management for recurrent laryngeal contact granuloma: A case report.

BACKGROUND: Laryngeal contact granuloma (LCG) is difficult to treat and frequently associated with high persistence and recurrence, despite the availability of both surgical and pharmacological treatment options. An appropriate strategy is therefore needed to help patients with multiple recurrences of LCG to potentially avoid unnecess-ary surgery. CASE SUMMARY: We describe the case of a 34-year-old male patient with recurrent LCG in which a good response was achieved through successful management of laryngophar-yngeal reflux disease using a combination pharmacotherapeutic regimen consisting of anti-reflux therapy, pepsin secretion inhibition, bile acid neutralization, and lifestyle modifications. This patient underwent surgery to excise the granuloma, then relapsed, underwent a second surgery, which was followed by a second recurrence. The granuloma then disappeared after 9 mo of combined treatment with ilaprazole enteric-coated capsules (10 mg qd), mosapride tablets (5 mg tid) and compound digestive enzyme capsules (2 tablets). The drug regimen was discontinued after one year, and no recurrence of the lesion has been reported during the one-year follow-up period. CONCLUSION: We report a combination of pharmacotherapeutics and lifestyle modifications for the management of laryngopharyngeal reflux disease to address recurring LCG.

SIRT1 and LSD1 competitively regulate KU70 functions in DNA repair and mutation acquisition in cancer cells.

Acquisition of BCR-ABL mutations underlies drug resistance of chronic myeloid leukemia (CML) to tyrosine kinase inhibitors, but the molecular mechanisms of mutation acquisition are poorly understood. We previously showed that lysine deacetylase sirtuin 1, SIRT1, promotes acquisition of BCR-ABL mutations in association with enhancing KU70 mediated non-homologous end joining DNA repair. In this study, we demonstrate that lysine specific demethylase 1 (LSD1) plays an opposite role to SIRT1 in regulating DNA repair and mutation acquisition. In response to therapeutic stress and DNA damage, LSD1 and SIRT1 compete for binding to KU70 on DNA damage foci globally and on the ABL locus. The recruitment of SIRT1 or LSD1 to KU70 impacts chromatin structure but does not correlate well with their direct histone modification functions, and SIRT1 helps maintain histone H4K16 acetylation and open chromatin for repair. The competitive KU70 binding by these proteins affects cancer cells' ability to repair broken DNA and acquire resistant genetic mutations in CML and prostate cancer cells. We identify that the core domain of KU70 binds both LSD1 and SIRT1, forming a molecular basis for the competition. The C-terminal SAP motif of KU70 mediates LSD1/SIRT1 competitive interaction by suppressing LSD1 binding to KU70 and ectopic expression of SAP-deleted KU70 to CML cells compromises their ability to acquire BCR-ABL mutations. Our study reveals a novel cellular stress response mechanism in cancer cells and a key role of LSD1/SIRT1/KU70 dynamic interaction in regulating DNA repair and mutation acquisition.

The emerging and diverse roles of sirtuins in cancer: a clinical perspective.

Sirtuins are a highly conserved family of nicotinamide adenine dinucleotide (NAD(+))-dependent protein lysine modifying enzymes with deacetylase, adenosine diphosphateribosyltransferase and other deacylase activities. Mammals have seven sirtuins, namely SIRT1-7. They are key regulators for a wide variety of cellular and physiological processes such as cell proliferation, differentiation, DNA damage and stress response, genome stability, cell survival, metabolism, energy homeostasis, organ development, aging, and cancer. Here we present an extensive literature review of the roles of mammalian sirtuins, particularly SIRT1 as that is the most studied sirtuin, in human epithelial, neuronal, hematopoietic, and mesenchymal malignancies, covering breast, prostate, lung, thyroid, liver, colon, gastric, pancreatic, ovarian, and cervical cancers, tumors of the central nervous system, leukemia and lymphoma, and soft tissue sarcomas. Collective evidence suggests sirtuins are involved in both promoting and suppressing tumorigenesis depending on cellular and molecular contexts. We discuss the potential use of sirtuin modulators, especially sirtuin inhibitors, in cancer treatment.

Sirtuins in hematological aging and malignancy.

Aging of the hematological system causes anemia, reduced immunity, and increased incidence of hematological malignancies. Hematopoietic stem cells (HSCs) play a crucial role in this process as their functions decline during aging. Sirtuins are a family of protein lysine modifying enzymes that have diverse roles in regulating metabolism, genome stability, cell proliferation, and survival, and have been implicated in mammalian aging and longevity. Here we provide an updated overview of sirtuins in aging research; particularly, how increased activity of SIRT1, SIRT3, or SIRT6 improves several aging parameters, and may possibly increase lifespan in mice. We review the literature on how sirtuins may play a role in HSC aging and hematological malignancies, and how key signaling pathways of HSCs may be affected by sirtuins. Among them, SIRT1 plays a critical role in chronic myelogenous leukemia, an age-dependent malignancy, and inhibition of SIRT1 sensitizes leukemic stem cells to tyrosine kinase inhibitor treatment and blocks acquisition of resistant oncogene mutations. In-depth understanding of sirtuins in HSC aging and malignancy may help design novel strategies to deter hematological aging and improve treatment of hematological malignancies.

Overcoming CML acquired resistance by specific inhibition of Aurora A kinase in the KCL-22 cell model.

Serine/threonine kinase Aurora A is essential for regulating mammalian cell division and is overexpressed in many types of human cancer. However, the role of Aurora A in chemoresistance of chronic myelogenous leukemia (CML) is not well understood. Using the KCL-22 cell culture model we have recently developed for studying mechanisms of CML acquired resistance, we found that Aurora A expression was partially reduced in these cells upon treatment with the tyrosine kinase inhibitor imatinib, which accompanied the acquisition of BCR-ABL mutation for imatinib resistance. Gene knockdown of BCR-ABL also reduced Aurora A expression, and conversely, Aurora A expression increased in hematopoietic progenitor cells after BCR-ABL expression. Inhibition of Aurora A induced apoptosis of CML cells with or without T315I BCR-ABL mutation and suppressed CML cell growth. Inhibition of Aurora A by gene knockdown or a highly specific small molecule inhibitor sensitized CML cells to imatinib treatment and effectively blocked acquisition of BCR-ABL mutations and KCL-22 cell relapse on imatinib, nilotinib or dasatinib. Our results show that Aurora A plays an important role for facilitating acquisition of BCR-ABL mutation and acquired resistance to tyrosine kinase inhibitors in the culture model and suggest that inhibition of Aurora A may provide an alternative strategy to improve CML treatment to overcome resistance.

[Clinical observation on acupuncture kinetotherapy for acute simple laryngitis of wind-heat type].

OBJECTIVE: To observe clinical therapeutic effect of acupuncture kinetotherapy for acute simple laryngitis of wind-heat type and to probe the mechanism. METHODS: Eighty cases were randomly divided into a test group and a control group, 40 cases in each group. The test group were treated with acupuncture kinetotherapy (Acupuncture was given at Kaiyin point No. 1 combined with deep respiratory movement of the glottis), once daily. The control group were treated with ultrasonic aerosol inhalation of 0.9% sodium chloride injection, gentamicin sulfate injection 80 000 U and Dexamethasone injection 5mg, twice a day. The treatment was given for 5 days for the 2 groups. RESULTS: The cured and markedly effective rate was 90.0% in the test group and 82.5% in the control group with no significant difference between the two groups (P>0.05); in the test group there was a very significant difference before and after treatment in the cumulative score of symptoms and the acoustic parameters (P<0.01). CONCLUSION: Acupuncture kinetotherapy has obvious therapeutic effect on acute simple laryngitis of wind heat type, with no toxic and adverse effects.

Tumor suppressor HIC1 directly regulates SIRT1 to modulate p53-dependent DNA-damage responses.

Hypermethylated in cancer 1 (HIC1) is an epigenetically regulated transcriptional repressor that functionally cooperates with p53 to suppress age-dependent development of cancer in mice. Here we show that the mechanism by which the loss of HIC1 function promotes tumorigenesis is via activating the stress-controlling protein SIRT1 and thereby attenuating p53 function. HIC1 forms a transcriptional repression complex with SIRT1 deacetylase, and this complex directly binds the SIRT1 promoter and represses its transcription. Inactivation of HIC1 results in upregulated SIRT1 expression in normal or cancer cells; this deacetylates and inactivates p53, allowing cells to bypass apoptosis and survive DNA damage. Inhibition of SIRT1 function in cells without HIC1 abolishes the resistance to apoptosis. Since aging increases promoter hypermethylation and epigenetic silencing of HIC1, we speculate that the resultant upregulation of SIRT1 may be a double-edged sword that both promotes survival of aging cells and increases cancer risk in mammals.

Inactivation of tumor suppressor genes: choice between genetic and epigenetic routes.

Inactivation of tumor suppressor genes can occur via epigenetic or genetic mechanisms. The reasons underlying this choice of gene inactivation routes during tumorigenesis have not been clarified, nor have the precise roles in cancer evolution for genes which are solely affected by epigenetically mediated loss of function. Here we discuss a mouse model in which the disruption of Hic1, a gene solely involved with epigenetic silencing in human cancer, can markedly influence the disruption of the powerful tumor suppressor gene, p53, in determining malignant tumor incidence, spectrum and virulence. Furthermore, the mechanism for inactivation of Hic1 in tumors produced can be switched from an epigenetic to a genetic mode depending on how the Hic1 and p53 knockouts are localized on mouse chromosome 11. The value of such a model and the implications of the findings for choice of epigenetically versus genetically determined loss of gene function in cancer are discussed.

Heterozygous disruption of Hic1 predisposes mice to a gender-dependent spectrum of malignant tumors.

The gene hypermethylated in cancer-1 (HIC1) encodes a zinc-finger transcription factor that belongs to a group of proteins known as the POZ family. HIC1 is hypermethylated and transcriptionally silent in several types of human cancer. Homozygous disruption of Hic1 impairs development and results in embryonic and perinatal lethality in mice. Here we show that mice disrupted in the germ line for only one allele of Hic1 develop many different spontaneous malignant tumors, including a predominance of epithelial cancers in males and lymphomas and sarcomas in females. The complete loss of Hic1 function in the heterozygous mice seems to involve dense methylation of the promoter of the remaining wild-type allele. We conclude that HIC1 is a candidate tumor-suppressor gene for which loss of function in both mouse and human cancers is associated only with epigenetic modifications.