BRCA2 deficiency increases sensitivity of medulloblastoma to Olaparib by inhibiting RAD51-mediated DNA damage repair system

PurposeBRCA2 defect exists in glioma and regulates drug resistance of glioma to chemotherapy. However, its role in medulloblastoma and the mechanism is not known. To investigate the effects of BRCA2 deficiency combined with Olaparib in medulloblastoma and the mechanism.MethodsBRCA2 was knocked down by RNAi technology and cell proliferation was detected by CCK-8 assay. Cell apoptosis was determined by FACS analysis when the in vivo role of BRCA2 was explored with xenograft mice model. Western blotting technology was used to explore the mechanism of BRCA2.ResultsKnockdown of BRCA2 enhanced the inhibitory effect of Olaparib on proliferation of Daoy and LN229 cells. The inhibition rate of Olaparib on Daoy or LN229 cells was 61.1%, 66.03% in shBRCA2 group, while it was 42.9%, 41.1% in shNC group. Overexpression of RAD51 partially reversed the effect of shBRCA2. In Daoy cells, apoptotic rate was 26.9% in Olaparib group and 58.9% in Olaparib/shBRCA2 group. However, it was 33.4% after RAD51 was overexpressed. It was the same in LN229 cells. In xenograft mice model, tumor volume in Olaparib and Olaparib/shBRCA2 group was 376.12 and 84.95mm3 when tumor weight was 0.46 g and 0.12 g. In addition, the level of RAD51, RAD50, MRE11, and NBS was increased by Olaparib alone but decreased reversely after knockdown of BRCA2 in Daoy cells.ConclusionsKnockdown of BRCA2 increases the sensitivity of medulloblastoma cells to Olaparib and strengthens the efficacy of Olaparib in vitro and in vivo. Knockdown of BRCA2 causes DNA damage repair by regulating RAD51-mediated signaling pathway in Daoy cells.

BRCA2 deficiency increases sensitivity of medulloblastoma to Olaparib by inhibiting RAD51-mediated DNA damage repair system.

PURPOSE: BRCA2 defect exists in glioma and regulates drug resistance of glioma to chemotherapy. However, its role in medulloblastoma and the mechanism is not known. To investigate the effects of BRCA2 deficiency combined with Olaparib in medulloblastoma and the mechanism. METHODS: BRCA2 was knocked down by RNAi technology and cell proliferation was detected by CCK-8 assay. Cell apoptosis was determined by FACS analysis when the in vivo role of BRCA2 was explored with xenograft mice model. Western blotting technology was used to explore the mechanism of BRCA2. RESULTS: Knockdown of BRCA2 enhanced the inhibitory effect of Olaparib on proliferation of Daoy and LN229 cells. The inhibition rate of Olaparib on Daoy or LN229 cells was 61.1%, 66.03% in shBRCA2 group, while it was 42.9%, 41.1% in shNC group. Overexpression of RAD51 partially reversed the effect of shBRCA2. In Daoy cells, apoptotic rate was 26.9% in Olaparib group and 58.9% in Olaparib/shBRCA2 group. However, it was 33.4% after RAD51 was overexpressed. It was the same in LN229 cells. In xenograft mice model, tumor volume in Olaparib and Olaparib/shBRCA2 group was 376.12 and 84.95mm3 when tumor weight was 0.46 g and 0.12 g. In addition, the level of RAD51, RAD50, MRE11, and NBS was increased by Olaparib alone but decreased reversely after knockdown of BRCA2 in Daoy cells. CONCLUSIONS: Knockdown of BRCA2 increases the sensitivity of medulloblastoma cells to Olaparib and strengthens the efficacy of Olaparib in vitro and in vivo. Knockdown of BRCA2 causes DNA damage repair by regulating RAD51-mediated signaling pathway in Daoy cells.

Transoral Thyroidectomy: Safety and Outcomes of 200 Consecutive North American Cases.

BACKGROUND: North American adoption of the transoral endoscopic thyroidectomy vestibular approach (TOETVA) has been limited due to concerns regarding the generalizability of published outcomes, as data are predominantly from Asian cohorts with a different body habitus. We describe our experience with TOETVA in a North American population in the context of the conventional transcervical approach thyroidectomy (TCA). STUDY DESIGN: Cases of TOETVA and TCA were reviewed from August 2017 to March 2020 at a tertiary care center. Outcomes included operative time, major (permanent recurrent laryngeal nerve (RLN) injury, permanent hypoparathyroidism, hematoma, conversion to open surgery), and minor complications. The TOETVA cohort was stratified into body mass index (BMI) classes of underweight/normal < 25 kg/m2, overweight 25-29.9 kg/m2, and obese ≥ 30 kg/m2 for comparative analysis. Multivariable logistic regression analyses were performed for odds of cumulative complication. RESULTS: Two hundred TOETVA and 333 TCA cases were included. There was no difference in incidence of major complications between the TOETVA and TCA cohorts (1.5% vs. 2.1%, p = 0.75). No difference was found in the rate of temporary RLN injury (4.5% vs. 2.1%, p = 0.124) or temporary hypoparathyroidism (18.2% vs. 12.5%, p = 0.163) for TOETVA and TCA, respectively. Surgical technique (TOETVA vs TCA) did not alter the odds of cumulative complication (OR 0.69 95% CI [0.26-1.85]) on logistic regression analysis. In the TOETVA cohort, higher BMI did not lead to a significantly greater odds of cumulative complication, 0.52 (95% CI [0.17-1.58]) and 1.69 (95% CI [0.74-3.88]) for the overweight and obese groups, respectively. CONCLUSION: TOETVA can be performed in a North American patient population without a difference in odds of complication compared to TCA. Higher BMI is not associated with greater likelihood of complication with TOETVA.

[Content determination and principal component analysis of nine active components in Paeonia lactiflora flowers from different cultivars and drying methods].

This study aims to establish an UPLC-DAD method for the simultaneous determination of nine active components in phenolic acids, anthocyanins, monoterpene glucosides and flavonoids in the petals of Paeonia lactiflora flowers from different cultivars and processing methods. UPLC analysis was performed on a Waters ACQUITY UPLC HSS T3 C_(18) column(2.1 mm × 100 mm, 1.8 µm)for gradient elution with a mobile phase consisting of 0.5% formic acid solution(A)-acetonitrile(B)at a flow rate of 0.3 mL·min~(-1).The detection wavelength was determined with a switched wavelength method and the column temperature maintained at 20 ℃, with an injection volume of 2 µL.The contents of the above components in the samples with different sources and treatment methods were obtained. The principal component analysis(PCA)of P. lactiflora flowers was conducted by using SIMCA 14.0 software, and the results showed that the P. lactiflora flowers could be classified into two categories according to cultivars, including P. lactiflora 'Bozhou-shaoyao' as one category with high contents of the above components, P. lactiflora 'Baihuachuanshaoyao' and P. lactiflora 'Honghuachuanshaoyao' as the other category. Dried P. lactiflora flowers could be classified into three categories, including baking-drying, sun-drying and shade-drying, with baking-drying method as the optimal one.The P. lactiflora flowers were not greatly affected by origins, growing altitudes, growing years, or blooming stages.The results of contents determination can be used to guide the cultivar selection, harvest and processing of P. lactiflora flowers.

Neuropsychiatric Symptoms and Risk Factors in Mild Cognitive Impairment: A Cohort Investigation of Elderly Patients.

BACKGROUND: Neuropsychiatric symptoms (NPS) have been shown to affect the progression and development of Alzheimer's disease (AD) in the elderly. However, the published data are still controversial and limited in large cohort-based NPS study. AIM: To explore the potential relationship between NPS and mild cognitive impairment (MCI) among the elderly of Chinese community. METHODS: A total of 465 Chinese community-dwelling elderly (age ≥ 60 years) with mild cognitive impairment (MCI) were recruited into this investigation. At baseline, enrolled participants were assessed for Clinical Dementia Rating (CDR), mini-psychiatric examination. They were also subjected to categorical language fluency test, list learning and delayed recall. We assessed the NPS severity by Neuropsychological Inventory (NPI). The global cognitive status (GCS) of the participants at the end of the 3-year study period were measured with the CDR. RESULTS: Approximately 41.6% of subjects had 1 or more NPS (total NPI score ≥ 1) at baseline. The most common NPSs were nocturnal behavior (20.8%), depression (17.3%), apathy (12.7%) and anxiety (13.2%). At the end of 3-year follow-up, 26.9% of baseline depressed patients developed AD, while 15.2% of baseline non-depressed patients developed AD (χ2 = 4.86, P=0. 04). Abnormal motor behavior was significantly correlated with cognitive deterioration as well (χ2 = 5.75, P=0. 03). Logistic regression analysis revealed that depression was considered as a risk factor for AD progression at baseline (95% CI: 1.12-5.67, OR=2.37, P=0.03). CONCLUSIONS: Depression may be an independent factor representing early neurodegeneration in elder patients with MCI. Further studies are warranted to assess whether effective management of NPS promotes the cognitive functions.

Sirtuin 6 promotes cell aging of myeloma cell line KM-HM_(31) by via Hippo signal pathway.

OBJECTIVE: Myeloma poses a serious risk for people's health and life quality. Molecular targeted treatment of myeloma emerges as a promising therapy. This study aimed to determine the effect of Sirtuin 6 on myeloma KM-HM_(31) cell aging and provide evidence for clinical treatment. MATERIALS AND METHODS: Myeloma KM-HM_(31) cell aging model induced by Carbamide peroxide (CP) was generated. Cells were transfected with Sirtuin 6 over-expression plasmid and specific siRNA. Western blot was used to study Sirtuin 6 expression, P53, P16, and Hippo in KM-HM_(31) cells. ß-galactosidase assay was applied to measure cell aging. Verteporfin inhibited Hippo signal pathway and measured aging of KM-HM_(31) cells. RESULTS: The levels of Sirtuin 6, aging protein P53, and P16 were remarkably elevated while Hippo expression was significantly inhibited in CP-induced KM-HM_(31) cells. Transfection of Sirtuin 6 over-expression plasmid enhanced Sirtuin 6 expression in KM-HM_(31) cells and potentiated cell aging with downregulation of Hippo protein. In contrast, a block of Sirtuin 6 resulted in the opposite effect. Moreover, Verteporfin inhibited Hippo signal pathway and enhanced CP-induced KM-HM_(31) cell aging, which contributed similar effect as Sirtuin 6 did. CONCLUSIONS: We showed that sirtuin 6 facilitates CP-induced myeloma cell KM-HM_(31) aging via suppressing Hippo.

Circulating exosomal miRNAs as diagnostic biomarkers in Parkinson's disease.

OBJECTIVE: This research has showed that exosomal miRNAs from cerebrospinal fluid could act as biomarkers for Parkinson's disease (PD). However, no analysis has been conducted to explore the potential value of exosomal miRNAs from plasma. PATIENTS AND METHODS: 52 patients with PD were included in study group. 48 healthy adults were included in control group. Blood samples were collected from all those people and then exosomes were extracted from the plasma. RESULTS: Compared with controls, patients with PD showed a significantly higher expression of circulating exosomal miR-331-5p. ROC curve showed that the area values under the curve of miR-331-5p and miR-505 were 0.849 and 0.898, respectively. CONCLUSIONS: Exosomal miRNAs, including miR-331-5p and miR-505, could potentially act as biomarkers for PD.

Pseudoaneurysm formation after valve sparing root replacement in children with Loeys-Dietz syndrome.

BACKGROUND: Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder predisposing patients to aneurysm formation and arterial dissection. Aortic root replacement is often performed prophylactically and valve-sparing root replacement (VSRR) has become the procedure of choice. However, in these patients with connective tissue disorders, postoperative pseudoaneurysms may develop. METHODS: All children with LDS undergoing VSRR at a single institution were retrospectively reviewed to identify patients who developed postoperative pseudoaneurysms. RESULTS: Thirty-one children with LDS underwent VSRR; four of these developed pseudoaneurysms of their synthetic aortic root grafts requiring reoperation. These four children were reviewed to investigate the cause of pseudoaneurysm formation after VSRR. Each had severe subtypes of LDS. Each underwent reoperation for repair of their pseudoaneurysms and were found to have suffered pseudoaneurysms as a result of tearing of sutures from their reimplantation VSRR. CONCLUSIONS: Pseudoaneurysms following aortic root replacement with VSRR can occur in children with severe subtypes of LDS. Long-term surveillance is required to detect these potentially life-threatening lesions.

The Role of Autophagy and the Chemokine (C-X-C Motif) Ligand 16 During Acute Lung Injury in Mice.

BACKGROUND Acute lung injury (ALI) is responsible for mortality in hospitalized patients. Autophagy can negatively regulate inflammatory response, and CXCL16 (chemokine (C-X-C motif) ligand 16) is a kind of chemokine, which is closely related to the inflammatory response. However, the relationship between autophagy and CXCL16 in ALI is still unclear. This study aimed to investigate the role of autophagy and chemokine CXCL16 in ALI in mice. MATERIAL AND METHODS Thirty-two male C57BL/6 mice were divided into four groups. The control group (C group) was given normal saline through intraperitoneal injection. The L group was given LPS (lipopolysaccharide) at 30 mg/kg to construct an ALI model. The 3-MA group received an intraperitoneal injection of inhibitor of autophagy 3-methyladenine at 15 mg/kg, 30 minutes before LPS injection. The anti-CXCL16 group was given 20 mg/kg of CXCL16 monoclonal antibody 30 minutes before the LPS injection. RESULTS In the 3-MA Group, the level of histological analysis, lung wet/dry ratio, total protein of BAL (bronchoalveolar lavage fluid) and TNF-a level were higher than the L group (p<0.05), the level of autophagy was lower than the L group (p<0.05), and the level of CXCL16 was higher than the L group (p<0.05). In the anti-CXCL16 group, the level of histological analysis, lung wet/dry ratio, BAL protein, and TNF-α level were declined compared to the L group (p<0.05), but there was no statistically significant difference in expression of CXCL16 detected by ELISA between the anti-CXCL16 group and the L group (p>0.05). CONCLUSIONS Autophagy played a protective role in ALI induced by LPS in mice. Autophagy could regulate the level of CXCL16. The chemokine CXCL16 could exacerbate ALI.

SmgGDS is a transient nucleolar protein that protects cells from nucleolar stress and promotes the cell cycle by regulating DREAM complex gene expression.

The chaperone protein and guanine nucleotide exchange factor SmgGDS (RAP1GDS1) is a key promoter of cancer cell proliferation and tumorigenesis. SmgGDS undergoes nucleocytoplasmic shuttling, suggesting that it has both cytoplasmic and nuclear functions that promote cancer. Previous studies indicate that SmgGDS binds cytoplasmic small GTPases and promotes their trafficking to the plasma membrane. In contrast, little is known about the functions of SmgGDS in the nucleus, or how these nuclear functions might benefit cancer cells. Here we show unique nuclear localization and regulation of gene transcription pathways by SmgGDS. Strikingly, SmgGDS depletion significantly reduces expression of over 600 gene products that are targets of the DREAM complex, which is a transcription factor complex that regulates expression of proteins controlling the cell cycle. The cell cycle regulators E2F1, MYC, MYBL2 (B-Myb) and FOXM1 are among the DREAM targets that are diminished by SmgGDS depletion. E2F1 is well known to promote G1 cell cycle progression, and the loss of E2F1 in SmgGDS-depleted cells provides an explanation for previous reports that SmgGDS depletion characteristically causes a G1 cell cycle arrest. We show that SmgGDS localizes in nucleoli, and that RNAi-mediated depletion of SmgGDS in cancer cells disrupts nucleolar morphology, signifying nucleolar stress. We show that nucleolar SmgGDS interacts with the RNA polymerase I transcription factor upstream binding factor (UBF). The RNAi-mediated depletion of UBF diminishes nucleolar localization of SmgGDS and promotes proteasome-mediated degradation of SmgGDS, indicating that nucleolar sequestration of SmgGDS by UBF stabilizes SmgGDS protein. The ability of SmgGDS to interact with UBF and localize in the nucleolus is diminished by expressing DiRas1 or DiRas2, which are small GTPases that bind SmgGDS and act as tumor suppressors. Taken together, our results support a novel nuclear role for SmgGDS in protecting malignant cells from nucleolar stress, thus promoting cell cycle progression and tumorigenesis.

Pyro-Borates, Spiro-Borates, and Boroxinates of BINOL-Assembly, Structures, and Reactivity.

VANOL and VAPOL ligands are known to react with three equivalents of B(OPh)3 to form a catalytic species that contains a boroxinate core with three boron atoms, and these have proven to be effective catalysts for a number of reactions. However, it was not known whether the closely related BINOL ligand will likewise form a boroxinate species. It had simply been observed that mixtures of BINOL and B(OPh)3 were very poor catalysts compared to the same mixtures with VANOL or VAPOL. Borate esters of BINOL have been investigated as chiral catalysts, and these include meso-borates, spiro-borates, and diborabicyclo-borate esters. Borate esters are often in equilibrium, and their structures can be determined by stoichiometry and/or thermodynamics, especially in the presence of a base. The present study examines the structures of borate esters of BINOL that are produced with different stoichiometric combinations of BINOL with B(OPh)3 in the presence and absence of a base. Depending on conditions, pyro-borates, spiro-borates, and boroxinate species can be generated and their effectiveness in a catalytic asymmetric aziridination was evaluated. The finding is that BINOL borate species are not necessarily inferior catalysts to those of VANOL and VAPOL but that, under the conditions, BINOL forms two different catalytic species (a boroxinate and a spiro-borate) that give opposite asymmetric inductions. However, many BINOL derivatives with substitutents in the 3- and 3'-positions gave only the boroxinate species and the 3,3'-Ph2BINOL ligand gave a boroxinate catalyst that gives excellent inductions in the aziridination reaction. BINOL derivatives with larger groups in the 3,3'-position will not form either spiro-borates or boroxinate species and thus are not effective catalysts at all.

[Mutations of vitamin D receptor gene found in patients with multiple myeloma].

Objective: To explore the mutations of vitamin D receptor (VDR) gene in patients with multiple myeloma (MM). Methods: Polymerase chain reaction (PCR) and direct DNA sequencing were used to detect the mutations of VDR gene(loci Fok Ⅰ, Bsm Ⅰ, Apa Ⅰ, Taq Ⅰ) in forty MM cases and 84 healthy control subjects. Results: A synonymous mutation (ATC→ATA , both encode isoleucine) at cDNA codon1421 of VDR gene was found in one MM patients, which correlated to a better therapeutic response. Rare Bsm Ⅰ AA genotype and Taq Ⅰ CC genotype were detected in a MM patient, which might be related to the relapsing and refracfory disease. Meanwhile, a rare allele(rs201747972, global MAF: A=0.0005/1), was found in another MM patient, which might be related to MM cell lines of two origins. rs11574113 G>C, rs2229829 C>A and rs201747972 C>T polymorphic loci(the same as Fok Ⅰ, Bsm Ⅰ, Apa Ⅰ and Taq Ⅰ) were found in a MM patient, which were associated with nonsense-mediated mRNA decay(NMD), contributing to the onset of MM. Conclusions: A new synonymous mutation, rare genotype, rare allele and new SNP are found in this study. These data enrich the genetic information of MM in China, and are helpful for the further research on MM pathogenesis.

Serum levels of the immunomodulatory protein, the progesterone induced blocking factor (PIBF) which is found in high levels during pregnancy is not higher in women with progesterone (P) receptor (R) positive vs. negative breast cancer.

PURPOSE: To determine if serum levels of the immunomodulatory protein, the progesterone induced blocking factor (PIBF), which is present in high levels during normal pregnancy, is present in higher levels in women with breast cancer positive for progesterone receptors. The study would also determine whether the presence or absence of the estrogen receptor in any way modifies PIBF expression. MATERIALS AND METHODS: PIBF using a research ELISA was evaluated in the follicular phase in 21 women with receptor status as follows: seven with estrogen receptor (ER)+ and progesterone receptor (PR)+, seven with ER- and PR+, and seven with ER+ and PR. RESULTS: The results showed no differences in serum PIBF in the three groups. The serum PIBF levels were no different than historical controls in the follicular phase. CONCLUSIONS: Measurement of serum PIBF does not seem to be an important marker to use to either detect women with breast cancer or to help determine tumor virulence or potential specific therapies. If PIBF plays a role in helping cancer cells to escape immune surveillance, it seems that the intracytoplasmic PIBF would be the form most likely operative.

The BET bromodomain inhibitor exerts the most potent synergistic anticancer effects with quinone-containing compounds and anti-microtubule drugs.

BET bromodomain inhibitors are very promising novel anticancer agents, however, single therapy does not cause tumor regression in mice, suggesting the need for combination therapy. After screening a library of 2697 small molecule compounds, we found that two classes of compounds, the quinone-containing compounds such as nanaomycin and anti-microtubule drugs such as vincristine, exerted the best synergistic anticancer effects with the BET bromodomain inhibitor JQ1 in neuroblastoma cells. Mechanistically, the quinone-containing compound nanaomycin induced neuroblastoma cell death but also activated the Nrf2-antioxidant signaling pathway, and the BET bromodomain proteins BRD3 and BRD4 formed a protein complex with Nrf2. Treatment with JQ1 blocked the recruitment of Nrf2 to the antioxidant responsive elements at Nrf2 target gene promoters, and JQ1 exerted synergistic anticancer effects with nanaomycin by blocking the Nrf2-antioxidant signaling pathway. JQ1 and vincristine synergistically induced neuroblastoma cell cycle arrest at the G2/M phase, aberrant mitotic spindle assembly formation and apoptosis, but showed no effect on cell survival in normal non-malignant cells. Importantly, co-treatment with JQ1 and vincristine synergistically suppressed tumor progression in neuroblastoma-bearing mice. These results strongly suggest that patients treated with BET bromodomain inhibitors in clinical trials should be co-treated with vincristine.

The mRNA-binding protein HuR promotes hypoxia-induced chemoresistance through posttranscriptional regulation of the proto-oncogene PIM1 in pancreatic cancer cells.

Previously, it has been shown that pancreatic ductal adenocarcinoma (PDA) tumors exhibit high levels of hypoxia, characterized by low oxygen pressure (pO2) and decreased O2 intracellular perfusion. Chronic hypoxia is strongly associated with resistance to cytotoxic chemotherapy and chemoradiation in an understudied phenomenon known as hypoxia-induced chemoresistance. The hypoxia-inducible, pro-oncogenic, serine-threonine kinase PIM1 (Proviral Integration site for Moloney murine leukemia virus 1) has emerged as a key regulator of hypoxia-induced chemoresistance in PDA and other cancers. Although its role in therapeutic resistance has been described previously, the molecular mechanism behind PIM1 overexpression in PDA is unknown. Here, we demonstrate that cis-acting AU-rich elements (ARE) present within a 38-base pair region of the PIM1 mRNA 3'-untranslated region mediate a regulatory interaction with the mRNA stability factor HuR (Hu antigen R) in the context of tumor hypoxia. Predominantly expressed in the nucleus in PDA cells, HuR translocates to the cytoplasm in response to hypoxic stress and stabilizes the PIM1 mRNA transcript, resulting in PIM1 protein overexpression. A reverse-phase protein array revealed that HuR-mediated regulation of PIM1 protects cells from hypoxic stress through phosphorylation and inactivation of the apoptotic effector BAD and activation of MEK1/2. Importantly, pharmacological inhibition of HuR by MS-444 inhibits HuR homodimerization and its cytoplasmic translocation, abrogates hypoxia-induced PIM1 overexpression and markedly enhances PDA cell sensitivity to oxaliplatin and 5-fluorouracil under physiologic low oxygen conditions. Taken together, these results support the notion that HuR has prosurvival properties in PDA cells by enabling them with growth advantages in stressful tumor microenvironment niches. Accordingly, these studies provide evidence that therapeutic disruption of HuR's regulation of PIM1 may be a key strategy in breaking an elusive chemotherapeutic resistance mechanism acquired by PDA cells that reside in hypoxic PDA microenvironments.

Steroid induction of therapy-resistant cytokeratin-5-positive cells in estrogen receptor-positive breast cancer through a BCL6-dependent mechanism.

Therapy resistance remains a major problem in estrogen receptor-α (ERα)-positive breast cancer. A subgroup of ERα-positive breast cancer is characterized by mosaic presence of a minor population of ERα-negative cancer cells expressing the basal cytokeratin-5 (CK5). These CK5-positive cells are therapy resistant and have increased tumor-initiating potential. Although a series of reports document induction of the CK5-positive cells by progestins, it is unknown if other 3-ketosteroids share this ability. We now report that glucocorticoids and mineralocorticoids effectively expand the CK5-positive cell population. CK5-positive cells induced by 3-ketosteroids lacked ERα and progesterone receptors, expressed stem cell marker, CD44, and displayed increased clonogenicity in soft agar and broad drug-resistance in vitro and in vivo. Upregulation of CK5-positive cells by 3-ketosteroids required induction of the transcriptional repressor BCL6 based on suppression of BCL6 by two independent BCL6 small hairpin RNAs or by prolactin. Prolactin also suppressed 3-ketosteroid induction of CK5+ cells in T47D xenografts in vivo. Survival analysis with recursive partitioning in node-negative ERα-positive breast cancer using quantitative CK5 and BCL6 mRNA or protein expression data identified patients at high or low risk for tumor recurrence in two independent patient cohorts. The data provide a mechanism by which common pathophysiological or pharmacologic elevations in glucocorticoids or other 3-ketosteroids may adversely affect patients with mixed ERα+/CK5+ breast cancer. The observations further suggest a cooperative diagnostic utility of CK5 and BCL6 expression levels and justify exploring efficacy of inhibitors of BCL6 and 3-ketosteroid receptors for a subset of ERα-positive breast cancers.

Efficacy of intestinal decompression with long nasointestinal tube and selective contrast radiography in the treatment of small bowel obstruction in elderly patients.

BACKGROUND: This study's aim was to assess the efficacy of intestinal decompression with long tube and selective intestinal radiography in the diagnosis and treatment of small bowel obstruction (SBO) in elderly patients. METHODS: Thirty-two elderly patients with SBO received intestinal decompression with a 300-cm long nasointestinal tube inserted into upper jejunum under radiographic control. The long tube was passed into the proximal part of obstruction or the proximal end of ileum driven by intestinal peristalsis. Selective contrast radiography was done using direct injection of double-contrast medium consisting of 20-100 mL of 76% gastrografin and 50-200 mL of air. The dynamic and multi-position radiographic observation was conducted. RESULTS: Intubation was successful in all 32 patients. SBO resolution was successful in 29/32 (90.6%) patients. The 3 remaining patients proceeded to undergo surgery. Radiographic findings showed no obvious abnormalities in 25/32 (78.1%) patients, adhesive SBO in 6/32 (18.6%), and metastatic intestinal tumor in 1/32 (3.1%) patient. CONCLUSIONS: Decompression using long tube can quickly and effectively relieve obstructive symptoms in elderly patients, and help to avoid emergency surgery and to resolve obstruction. Concurrent contrast radiography is helpful to verify the location and degree of obstruction, and to reveal the cause of the obstruction.

Prolactin suppresses a progestin-induced CK5-positive cell population in luminal breast cancer through inhibition of progestin-driven BCL6 expression.

Prolactin controls the development and function of milk-producing breast epithelia but also supports growth and differentiation of breast cancer, especially luminal subtypes. A principal signaling mediator of prolactin, Stat5, promotes cellular differentiation of breast cancer cells in vitro, and loss of active Stat5 in tumors is associated with antiestrogen therapy failure in patients. In luminal breast cancer, progesterone induces a cytokeratin-5 (CK5)-positive basal cell-like population. This population possesses characteristics of tumor stem cells including quiescence, therapy resistance and tumor-initiating capacity. Here we report that prolactin counteracts induction of the CK5-positive population by the synthetic progestin (Pg) R5020 in luminal breast cancer cells both in vitro and in vivo. CK5-positive cells were chemoresistant as determined by fourfold reduced rate of apoptosis following docetaxel exposure. Pg-induction of CK5 was preceded by marked upregulation of BCL6, an oncogene and transcriptional repressor critical for the maintenance of leukemia-initiating cells. Knockdown of BCL6 prevented induction of CK5-positive cell population by Pg. Prolactin suppressed Pg-induced BCL6 through Jak2-Stat5 but not Erk- or Akt-dependent pathways. In premenopausal but not postmenopausal patients with hormone receptor-positive breast cancer, tumor protein levels of CK5 correlated positively with BCL6, and high BCL6 or CK5 protein levels were associated with unfavorable clinical outcome. Suppression of Pg-induction of CK5-positive cells represents a novel prodifferentiation effect of prolactin in breast cancer. The present progress may have direct implications for breast cancer progression and therapy as loss of prolactin receptor-Stat5 signaling occurs frequently and BCL6 inhibitors currently being evaluated for lymphomas may have value for breast cancer.

Expression of cyclin D1a and D1b as predictive factors for treatment response in colorectal cancer.

BACKGROUND: The aim of this study was to investigate the value of the cyclin D1 isoforms D1a and D1b as prognostic factors and their relevance as predictors of response to adjuvant chemotherapy with 5-fluorouracil and levamisole (5-FU/LEV) in colorectal cancer (CRC). METHODS: Protein expression of nuclear cyclin D1a and D1b was assessed by immunohistochemistry in 335 CRC patients treated with surgery alone or with adjuvant therapy using 5-FU/LEV. The prognostic and predictive value of these two molecular markers and clinicopathological factors were evaluated statistically in univariate and multivariate survival analyses. RESULTS: Neither cyclin D1a nor D1b showed any prognostic value in CRC or colon cancer patients. However, high cyclin D1a predicted benefit from adjuvant therapy measured in 5-year relapse-free survival (RFS) and CRC-specific survival (CSS) compared to surgery alone in colon cancer (P=0.012 and P=0.038, respectively) and especially in colon cancer stage III patients (P=0.005 and P=0.019, respectively) in univariate analyses. An interaction between treatment group and cyclin D1a could be shown for RFS (P=0.004) and CSS (P=0.025) in multivariate analysis. CONCLUSION: Our study identifies high cyclin D1a protein expression as a positive predictive factor for the benefit of adjuvant 5-FU/LEV treatment in colon cancer, particularly in stage III colon cancer.