TBK1 Provides Context-Selective Support of the Activated AKT/mTOR Pathway in Lung Cancer

Emerging observations link dysregulation of TANK-binding kinase 1 (TBK1) to developmental disorders, inflammatory disease, and cancer. Biochemical mechanisms accounting for direct participation of TBK1 in host defense signaling have been well described. However, the molecular underpinnings of the selective participation of TBK1 in a myriad of additional cell biological systems in normal and pathophysiologic contexts remain poorly understood. To elucidate the context-selective role of TBK1 in cancer cell survival, we employed a combination of broad-scale chemogenomic and interactome discovery strategies to generate data-driven mechanism-of-action hypotheses. This approach uncovered evidence that TBK1 supports AKT/mTORC1 pathway activation and function through direct modulation of multiple pathway components acting both upstream and downstream of the mTOR kinase itself. Furthermore, we identified distinct molecular features in which mesenchymal, Ras-mutant lung cancer is acutely dependent on TBK1-mediated support of AKT/mTORC1 pathway activation for survival. Cancer Res; 77(18); 5077-94. ©2017 AACR.

XPO1-dependent nuclear export is a druggable vulnerability in KRAS-mutant lung cancer

The common participation of oncogenic KRAS proteins in many of the most lethal human cancers, together with the ease of detecting somatic KRAS mutant alleles in patient samples, has spurred persistent and intensive efforts to develop drugs that inhibit KRAS activity. However, advances have been hindered by the pervasive inter- and intra-lineage diversity in the targetable mechanisms that underlie KRAS-driven cancers, limited pharmacological accessibility of many candidate synthetic-lethal interactions and the swift emergence of unanticipated resistance mechanisms to otherwise effective targeted therapies. Here we demonstrate the acute and specific cell-autonomous addiction of KRAS-mutant non-small-cell lung cancer cells to receptor-dependent nuclear export. A multi-genomic, data-driven approach, utilizing 106 human non-small-cell lung cancer cell lines, was used to interrogate 4,725 biological processes with 39,760 short interfering RNA pools for those selectively required for the survival of KRAS-mutant cells that harbour a broad spectrum of phenotypic variation. Nuclear transport machinery was the sole process-level discriminator of statistical significance. Chemical perturbation of the nuclear export receptor XPO1 (also known as CRM1), with a clinically available drug, revealed a robust synthetic-lethal interaction with native or engineered oncogenic KRAS both in vitro and in vivo. The primary mechanism underpinning XPO1 inhibitor sensitivity was intolerance to the accumulation of nuclear IκBα (also known as NFKBIA), with consequent inhibition of NFκB transcription factor activity. Intrinsic resistance associated with concurrent FSTL5 mutations was detected and determined to be a consequence of YAP1 activation via a previously unappreciated FSTL5-Hippo pathway regulatory axis. This occurs in approximately 17% of KRAS-mutant lung cancers, and can be overcome with the co-administration of a YAP1-TEAD inhibitor. These findings indicate that clinically available XPO1 inhibitors are a promising therapeutic strategy for a considerable cohort of patients with lung cancer when coupled to genomics-guided patient selection and observation.

Prognostic factors for successful outcome in patients undergoing controlled ovarian stimulation and intrauterine insemination

OBJECTIVE

To determine the prognostic factors associated with successful outcome following controlled ovarian stimulation and intrauterine insemination.

DESIGN

Retrospective analysis.

SETTING

University-based assisted reproductive technology centre, Hong Kong.

PATIENTS AND METHODS

Patients included 292 couples undergoing 600 treatment cycles, following a standard protocol of human menopausal gonadotrophin injections. Multiple logistic regression analysis was performed to determine which demographic and sperm parameters gave the maximum discrimination to predict pregnancy.

RESULTS

One hundred and eleven pregnancies resulted from treatment. The pregnancy rates were 18.5% per cycle and 37.9% per couple. The age of the women was significantly lower for pregnant cycles, and the serum oestradiol levels and number of follicles greater than 16 mm in diameter were significantly higher, compared with non-pregnant cycles. The sperm concentration and number of motile spermatozoa were also significantly increased in pregnant cycles. Pregnancy rate was significantly increased when the raw semen sample contained 20 million/mL or more spermatozoa, normal forms comprised 7% or more, and when the number of motile spermatozoa in inseminated samples was 1 million or greater.

CONCLUSION

Using multiple logistic regression analysis, age of the women and serum oestradiol level had the maximum power to predict pregnancy following ovarian stimulation and intrauterine insemination.

A comparative study of raw and prepared semen samples from two consecutive days

OBJECTIVE

To study and compare raw and prepared semen samples from two consecutive days by conventional sperm parameters, various motility characteristics of spermatozoa determined by computer-aided sperm analysis and calcium ionophore-induced acrosome reaction.

STUDY DESIGN

Semen samples of male partners in couples undergoing 81 cycles of double intrauterine insemination were studied. The first sample was produced after abstinence of 2-7 days and the second, 24 hours after the first. Both samples were processed by isolate sperm separation medium.

RESULTS

Semen volume, sperm concentration and total motile spermatozoa were significantly reduced in day 2 raw and prepared samples, whereas normal morphology, motility characteristics and percentage of acrosome-reacted spermatozoa increased significantly in day 2 inseminated samples as compared to day 1. Oligospermic, asthenospermic and teratozoospermic samples showed a significant improvement in concentration, various motility characteristics and normal morphology of spermatozoa in day 2 samples as compared to day 1.

CONCLUSION

Men with normal samples showed improvements in normal morphology and acrosome-reacted spermatozoa, whereas those with subnormal semen samples from day 1 showed a significant improvement in concentration, various spermatozoal velocities and normal morphology on day 2.

Comparison of two colloidal silica-based sperm separation media with a non-silica-based medium

OBJECTIVE

To study and compare the effects of three sperm separation media, two silica-based (Percoll; Pharmacia Biotech AB, Uppsala, Sweden, and Isolate; Irvine Scientific, Santa Ana, CA) and one non-silica-based (Ixaprep; Medicult, Copenhagen, Denmark), on the recovery of progressive motile sperm, the percentage of sperm with normal morphology, various sperm motion characteristics determined by computer-aided sperm analysis, and the percentage of acrosome-reacted sperm.

DESIGN

Prospective study.

SETTING

A university-based assisted reproductive technology center.

PATIENT(S)

Male partners of couples attending our infertility clinic.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Various semen parameters.

RESULT(S)

Both Isolate and Ixaprep resulted in enhanced recovery of motile spermatozoa compared with Percoll. The percentage of sperm with forward progressive motility, the percentage of sperm with normal morphology, and various sperm motion characteristics were similar after the use of Percoll and Isolate and were significantly better than after the use of Ixaprep. The same percentage of acrosome-reacted spermatozoa was observed with all three media. Similar results were observed in both normal and subnormal semen samples.

CONCLUSION(S)

The use of Isolate and Ixaprep resulted in better recovery of motile spermatozoa. Other semen parameters were similar with the use of Isolate and Percoll, whereas the use of Ixaprep was associated with lower sperm velocities and fewer morphologically normal spermatozoa.