Integrating transcriptome-wide association study and mRNA expression profiling identifies novel genes associated with bone mineral density

To scan novel candidate genes associated with osteoporosis, a two-stage transcriptome-wide association study (TWAS) of bone mineral density (BMD) was conducted. The BMD-associated genes identified by TWAS were then compared with the gene expression profiling of BMD in bone cells, B cells, and mesenchymal stem cells. We identified multiple candidate genes and gene ontology (GO) terms associated with BMD.

INTRODUCTION

Osteoporosis (OP) is a metabolic bone disease characterized by decrease in BMD. Our objective is to scan novel candidate genes associated with OP.

METHODS

A transcriptome-wide association study (TWAS) was performed by integrating the genome-wide association study (GWAS) summary of bone mineral density (BMD) with two pre-computed mRNA expression weights of peripheral blood and muscle skeleton. Then, another independent GWAS data of BMD was used to verify the discovery results. The BMD-associated genes identified between discovery and replicate TWAS were further subjected to gene ontology (GO) analysis implemented by DAVID. Finally, the BMD-associated genes and GO terms were further compared with the mRNA expression profiling results of BMD to detect the common genes and GO terms shared by both DNA-level TWAS and mRNA expression profile analysis.

RESULTS

TWAS identified 95 common genes with permutation P value < 0.05 for peripheral blood and muscle skeleton, such as TMTC4 in muscle skeleton and DDX17 in peripheral blood. Further comparing the genes detected by discovery-replicate TWAS with the differentially expressed genes identified by mRNA expression profiling of OP patients found 18 overlapped genes, such as MUL1 in muscle skeleton and SPTBN1 in peripheral blood. GO analysis of the genes identified by discovery-replicate TWAS detected 12 BMD-associated GO terms, such as negative regulation of cell growth and regulation of glycogen catabolic process. Further comparing the GO results of discovery-replicate TWAS and mRNA expression profiles found 6 overlapped GO terms, such as membrane and cell adhesion.

CONCLUSION

Our study identified multiple candidate genes and GO terms for BMD, providing novel clues for understanding the genetic mechanism of OP.

[Prognostic study of 229 follicular lymphoma patients treated with rituximab combined with chemotherapy]

目的

探究滤泡性淋巴瘤（FL）的临床特征，以及FL国际预后指数（FLIPI）、FLIPI2、IPI、修正IPI（R-IPI）、NCCN-IPI在中国FL患者的预后意义。

方法

对2008年11月至2018年4月期间以利妥昔单抗联合CHOP（环磷酰胺、多柔比星、长春新碱及泼尼松）方案治疗的229例初治FL患者资料进行回顾性分析，并对所有患者进行各项预后指数评分。对201例完成化疗且有完整随访记录的患者进行单因素及多因素生存分析。

结果

229例患者中男126例，女103例，中位年龄53（21~82）岁。①对上述预后评分系统中所含的危险因素在患者总生存（OS）和无进展生存（PFS）中的影响进行分析，单因素分析结果显示：年龄>60岁、HGB<120 g/L、血β₂微球蛋白升高、骨髓浸润及C反应蛋白（CRP）升高是影响患者OS和PFS的不良因素（P值均<0.05），利妥昔单抗维持组（RM）与非维持组（non-RM）患者的5年OS率分别为93.33%、87.10%（P=0.020），5年PFS率分别为90.81%、63.47%（P=0.003），前者均优于后者；多因素分析结果显示：HGB<120 g/L（P=0.001）、骨髓浸润（P=0.050）、CRP升高（P=0.010）和non-RM（P=0.010）是影响OS的不良预后因素，HGB<120 g/L（P=0.003）、CRP升高（P=0.009）和non-RM（P=0.003）是影响PFS的不良预后因素。②对FLIPI和FLIP2评分预后模型进行比较分析，结果显示：FLIPI预后模型中，低危、中危和高危组患者的5年OS率（P=0.230）和5年PFS率（P=0.160）差异均无统计学意义。FLIP2预后模型中，5年OS率和5年PFS率差异均有统计学意义（P值均<0.001），在利妥昔单抗治疗组中进行分析，低危、中危和高危组患者的5年OS率分别为96.77%、88.89%、80.00%，差异有统计学意义（P=0.042）。

结论

利妥昔单抗时代FLIPI2可以更好地用于FL危险分层。

[Prognostic significance of NCCN-International Prognostic Index (NCCN-IPI) for patients with peripheral T-cell lymphoma treated with CHOP-based chemotherapy]

目的

明确美国国家综合癌症网络国际预后指数（NCCN-IPI）对外周T细胞淋巴瘤（PTCL）患者化疗后的预后评估价值。

方法

回顾性分析2003年1月至2013年5月接受CHOP或CHOP样方案化疗的162例初治PTCL患者的临床资料，采用国际预后指数（IPI）和NCCN-IPI进行危险分层和预后评估。

结果

①162例患者预期5年总生存（OS）和无进展生存（PFS）率分别为33%和20%，中位OS和PFS时间分别为17.0和9.2个月。②多因素分析提示美国东部肿瘤协作组体能状态评分（ECOG评分）≥2分（PFS：HR＝2.418，95%CI 1.535～3.809，P<0.001；OS：HR＝2.347，95%CI 1.435～3.839，P＝0.001）和存在特定的结外病变部位（PFS：HR＝1.800，95%CI 1.216～2.665，P＝0.003；OS：HR＝1.608，95%CI 1.054～2.454，P＝0.027）是影响患者PFS和OS的独立危险因素；ALK⁺是影响间变性大细胞淋巴瘤患者PFS（HR＝0.424，95%CI 0.184～0.975，P＝0.043）及OS（HR＝0.276，95%CI 0.087～0.877，P＝0.029）的独立预后良好因素。③NCCN-IPI低危组患者的生存率显著高于IPI低危组患者（5年OS率74%对54%，χ²＝5.041，P＝0.025；5年PFS率50%对38%，χ²＝5.295，P＝0.021），差异均有统计学意义。

结论

NCCN-IPI较IPI对低危PTCL患者具有更好的预后判断意义，可作为PTCL患者有效的预后分层工具。

[Robot-assisted partial nephrectomy for treating renal hilar tumors: a clinical study of 22 cases]

Objective: To analyze and summarize the surgical experience of robotic-assisted laparoscopic partial nephrectomy (RAPN) for treating renal hilar tumors, and assess the efficacy and safety of this surgery. Methods: The clinical data of 22 renal hilar tumor patients who underwent RAPN in Sir Run Run Shaw Hospital, Zhejiang University School of Medicine between September 2015 and September 2017 was analyzed. The patients included 19 males and 3 females, with an average age of (55.6 ±13.0) years old and the age range was 28-75 years. In 13 cases, the tumors were in left kidney, and 9 in the right. There were 10 large tumors (>4 cm diameter), the average tumor size was (3.7±1.9) cm. Preoperative glomerular filtration rate was normal in all cases. Results: The surgery was successfully finished in all of the cases, with no conversion to open surgery. The mean duration of the surgery was 80-270 min, with an average of (134.7±44.5) min. The blood loss was 80-500 ml, with an average of (135.9±130.7) ml, and none of the cases needed intraoperative blood transfusion. The warm ischemia time was 8-25 min, with an average of (18.2±4.0) min. The postoperative length of hospitalization was 7-23 d, with an average of (11.5±4.1) d. Serious gross hematuria occurred in 1 patient, and paroxysmal atrial fibrillation occurred in 1 patient after surgery. The post-operative pathology showed renal clear cell carcinoma in 18 cases, papillary renal cell carcinoma in 2 cases, chromophobe cell carcinoma in 1 case and well differentiated neuroendocrine tumor in 1 case. The tumor resection margin was negative in all cases. Neither local recurrence nor metastasis was observed during a follow-up of 1 to 15 months. Renal function of all the patients was in normal range. Conclusion: RAPN is a safe, useful approach and a minimally invasive operation for treating renal hilar tumors and it owns crucial advantages in complete and accurate resection of the renal hilar tumors and the reconstruction of the kidney.

Fundamental supply of skin blood flow in the Chinese Han population: Measurements by a full-field laser perfusion imager

BACKGROUND

Skin blood flow is believed to link with many diseases, and shows a significant heterogeneity. There are several papers on basal cutaneous microcirculation perfusion in different races, while the data in Chinese is vacant.

OBJECTIVE

The aim was to establish the database of absolute fundamental supply of skin blood flow in the Chinese Han population.

METHODS

With a full-field laser perfusion imager (FLPI), the skin blood flow can be quantified. Cutaneous perfusion values were determined in 17 selected skin areas in 406 healthy participants aged between 20 and 80 years (mean 35.05 ± 11.33). Essential parameters such as weight, height were also measured and values of BMI were calculated. The perfusion values were reported in Arbitrary Perfusion Units (APU).

RESULTS

The highest cutaneous perfusion value fell on eyelid (931.20 ± 242.59 in male and 967.83 ± 225.49 in female), and pretibial had the lowest value (89.09 ± 30.28 in male and 85.08 ± 33.59 in female). The values were higher in men than women on the bank of fingertips, nose, forehead, cheek, neck and earlobe (P < .05). Perfusion values on stretch and flexion side of forearm had negative correlation with age (P = .01 and P = 4.88 × 10^-3 , respectively) in male. Abdomen was negatively correlated with BMI in both gender (P = .02, respectively).

CONCLUSIONS

Skin blood flow values vary with skin regions. There is a tendency to measure higher perfusion values in men than in women. And the values are irrelevant with age or BMI.

Abstract P5-14-04: A novel implant to deliver localized hormonal therapy to prevent and treat breast cancer

Most cancer treatment and prevention strategies include removal of the respective organ or systemic therapy. Early interception and cancer prevention is fraught with uncertainties in individual risk assessment and the absence of early surrogate markers to monitor efficacy. Hence, cancer prevention studies typically require large patient numbers. They are performed in unselected populations without clearly defined risk and benefits are often small or diluted. Hence, even successful strategies with documented benefit such as tamoxifen, have found only poor uptake in the at-risk population. Many women and providers are deterred by the low benefits to risk ratio of systemic tamoxifen exposure. The opportunity to selectively treat with an effective agent would limit the need for surgery and circumvent systemic exposure.

We propose a less toxic and less debilitating approach to prevent and treat early stage breast cancer by utilizing the slow release of anti-estrogens from silastic tubing as a local drug delivery device to the breast. Our in vitro and in vivo data demonstrate consistent release of active fulvestrant through at least 52 weeks. Extrapolating from the amount of residual drug left in the tubing after 52 weeks suggests that drug release could be maintained sufficiently to and beyond 5 years. Silastic tubing released fulvestrant at clinically relevant concentrations and associated with inhibition of ER signaling and cell proliferation in vitro. In vivo anti-tumor activity was comparable to systemic administration of the anti-estrogen. The silastic tubing preferentially delivered the anti-estrogen to mammary tissue with minimal accumulation in major organs and 20-fold lower concentrations in adjacent (abdominal) and distant fat (thoracic) pads. Consistent with fulvestrant penetrance through tumors, local delivery was more effective in reducing Ki-67 immediately adjacent to the tubing but maintained concentrations comparable to systemic therapy throughout the entire tumors. We further demonstrated that human fat cells readily take up fulvestrant and then transfer the drug to breast cancer cells. These findings support the use of local drug delivery through the human breast tissue and surrounding fatty tissue. Mammary tissues are rapidly cleared of fulvestrant upon removal of the drug-loaded tubing. This would allow the long term implantation of a drug delivery device designed to be emptied or refilled.

Local drug delivery is ideally suited in a setting of local disease or recurrence with minimal risk for systemic metastases with the goal of producing high concentrations without systemic application of the drug. Our data support the concept of a local silastic tubing device as a means to locally deliver an anti-estrogen in three major applications: early interventions for localized tumors, such as ductal carcinoma in situ (DCIS) or early stage breast cancer with low metastatic potential, prevention of breast cancer in women at higher risk due genetic predisposition, or used in concert with systemic therapy to provide a localized therapeutic boost. Overall, the use of implantable silastic tubing for local drug delivery represents a promising approach and introduces a potential paradigm shift in prevention and treatment of breast cancer.

Citation Format: Munster PN, Park J, Desai P, Garcia E, Cheng S, Greier S, Pawlowska N, Chaudhuri AR, Thomas S. A novel implant to deliver localized hormonal therapy to prevent and treat breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-14-04.