Traumatic Neuroma in the External Auditory Canal

Traumatic neuroma is the reparative proliferation of axons and Schwann cells at the proximal end of a severed nerve following injury or surgery. Traumatic neuromas with or without clinical symptoms have rarely been reported in the external auditory canal. A 50-year-old woman with a history of trauma visited our otorhinolaryngology clinic with a 7 × 5-mm mass localized on the anterior wall of the external auditory canal. The mass was easily removed via surgical excision and was histopathologically diagnosed as a neuroma. No signs of recurrence were observed after excision. Herein, the authors present this case, along with a review of the literature.

Benefits of Soybean in the Era of Precision Medicine: A Review of Clinical Evidence

Soybean (Glycine max) is an important ingredient of cuisines worldwide. While there is a wealth of evidence that soybean could be a good source of macronutrients and phytochemicals with health-promoting effects, concerns regarding adverse effects have been raised. In this work, we reviewed the current clinical evidence focusing on the benefits and risks of soybean ingredients. In breast, prostate, colorectal, ovarian, and lung cancer, epidemiological studies showed an inverse association between soybean food intake and cancer risks. Soybean intake was inversely correlated with risks of type 2 diabetes mellitus (T2DM), and soy isoflavones ameliorated osteoporosis and hot flashes. Notably, soybean was one of the dietary protein sources that may reduce the risk of breast cancer and T2DM. However, soybean had adverse effects on certain types of drug treatment and caused allergies. In sum, this work provides useful considerations for planning clinical soybean research and selecting dietary protein sources for human health.

Orobol, 3'-hydroxy-genistein, suppresses the development and regrowth of cutaneous SCC

Chronic solar ultraviolet exposure is a major risk factor for cutaneous squamous cell carcinoma (cSCC), which is the second most common type of skin cancer. Our previous data showed that total protein and phosphorylation levels of T-LAK cell-originated protein kinase (TOPK) were enhanced in solar-simulated light (SSL)-induced skin carcinogenesis and overexpressed in actinic keratosis (AK) and cSCC human skin tissues compared to those in matched normal skin. Thus, targeting TOPK activity could be a helpful approach for treating cSCC. Our data showed that orobol directly binds to TOPK in an ATP-independent manner and inhibits TOPK kinase activity. Furthermore, orobol inhibited anchorage-independent colony formation by SCC12 cells in a dose-dependent manner. After discontinuing the treatment, patients commonly return to tumor-bearing conditions; therefore, therapy or intermittent dosing of drugs must be continued indefinitely. Thus, to examine the efficacy of orobol against the development and regrowth of cSCC, we established mouse models including prevention, and therapeutic models on the chronic SSL-irradiated SKH-1 hairless mice. Early treatment with orobol attenuates chronic SSL-induced cSCC development. Furthermore, orobol showed therapeutic efficacy after the formation of chronic SSL irradiation-induced tumor. In the mouse model with intermittent dosing of orobol, our data showed that re-application of orobol is effective for reducing tumor regrowth after discontinuation of treatment. Moreover, oncogenic protein levels were significantly attenuated by orobol treatment in the SSL-stimulated human skin. Thus, we suggest that orobol, as a promising TOPK inhibitor, could have an effective clinical approach to prevent and treat the development and regrowth of cSCC.

Evaluation of the efficacy and safety of conventional and interlaminar full-endoscopic decompressive laminectomy to treat lumbar spinal stenosis (ENDO-F trial): Protocol for a prospective, randomized, multicenter trial

Lumbar spinal stenosis is a common spinal degenerative condition. Minimally invasive interlaminar full-endoscopic decompressive laminectomy provides greater patient satisfaction and faster recovery than open decompressive laminectomy. The aim of our randomized controlled trial will be to compare the safety and efficacy of interlaminar full-endoscopic laminectomy and open decompressive laminectomy. Our trial will include 120 participants (60 per group) who will undergo surgical treatment for lumbar spinal stenosis. The primary outcome will be the Oswestry Disability Index measured at 12 months postoperatively. Secondary patient-reported outcomes will include back and radicular leg pain measured via a visual analog scale; the Oswestry Disability Index; the Euro-QOL-5 Dimensions score measured at 2 weeks and at 3, 6, and 12 months postoperatively; and patient satisfaction. The functional measures will include time to return to daily activities postoperatively and walking distance/time. The surgical outcomes will include postoperative drainage, operation time, duration of hospital stay, postoperative creatine kinase (an indicator of muscle injury) level, and postoperative surgical scarring. Magnetic resonance and computed tomography images and simple radiographs will be obtained for all patients. The safety outcomes will include surgery-related complications and adverse effects. All evaluations will be performed by a single assessor at each participating hospital who will be blinded to group allocation. The evaluations will be conducted preoperatively and at 2 weeks and 3, 6, and 12 months postoperatively. The randomized, multicenter design of the trial, blinding, and justification of the sample size will reduce the risk of bias in our trial. The results of the trial will provide data regarding the use of interlaminar full-endoscopic laminectomy as an alternative to open decompressive laminectomy that results in similar surgical findings with less invasiveness. Trial registration: This trial is registered at cris.nih.go.kr. (KCT0006198; protocol version 1; 27 May 2021).

Wire perforation of the missed tiny aneurysm originating from the fenestrated A1 segment during the endovascular approach

Vascular anomaly and aneurysmal formation of an anterior communicating artery (ACOM) complex has often been reported. Because of such a complicated relationship between the vascular structure and aneurysms, ACOM aneurysm is one of the most difficult aneurysms to treat among other common anterior circulation aneurysms. We herein report a case of wire perforation of a missed tiny aneurysm arising from the fenestrated A1 segment during the endovascular approach to ACOM aneurysm. Although the fenestration of A1 segment is a rare vascular anomaly, it is likely to accompany saccular type aneurysms in the vicinity of the vascular anomaly. Endovascular treatment for ACOM aneurysm requires more detailed evaluations of the accompanying vascular anomaly and hemodynamics around ACOM to avoid complications.

Development and Validation of Quantitative Analysis Method for Phenanthrenes in Peels of the Dioscorea Genus

Phenanthrenes are bioactive phenolic compounds found in genus Dioscorea, in which they are distributed more in peel than in flesh. Recent studies on phenanthrenes from Dioscorea sp. peels have revealed the potential for valuable biomaterials. Herein, an analytical method using high-performance liquid chromatography (HPLC) for quantitation of bioactive phenanthrenes was developed and validated. The calibration curves were obtained using the phenanthrenes (1-3) previously isolated from Dioscorea batatas concentrations in the range of 0.625-20.00 μg/ml with a satisfactory coefficient of determination (R²) of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) values of the isolated phenanthrenes ranged from 0.78-0.89 and 2.38-2.71 μg/ml, respectively. The intraday and interday precision ranged from 0.25-7.58%. The recoveries of the isolated phenanthrenes were from 95 to 100% at concentrations of 1.25, 2.5, and 5.0 μg/ml. Additionally, phenanthrenes (1-3) were found in all investigated peel extracts. Hence, the developed method was encouraging for the quantitative analysis of phenanthrenes in genus Dioscorea.

The Time Course of Monocytes Infiltration After Acoustic Overstimulation

Cochlea macrophages regulate cochlea inflammation and may harbors the potentials to protect hearing function from injury, including acoustic overstimulation. Cochlea macrophage numbers increase at 3–7 days after acoustic stimulation. However, the exact timing of macrophage infiltration and maturation from inflammatory monocytes is unclear. Furthermore, neutrophils may also be involved in this process. Therefore, in this study, we investigated time-dependent immune cell infiltration, macrophage transformation, and neutrophil involvement following acoustic stimulation. Flow cytometry and immunofluorescence were conducted in C-X3-C motif chemokine receptor 1 (CX3CR1)+/GFP mice after acoustic overstimulation (at baseline and at 1, 2, 3, and 5 days after exposure to 120 dB for 1 h) to identify inflammatory monocytes in the cochlea. RNA-sequencing and quantitative polymerase chain reaction were performed to identify differentially expressed genes. Inflammatory monocytes infiltrated into the lower portion of the lateral wall within 2 days after acoustic overstimulation (dpn), followed by transformation into macrophages at 3–5 dpn via CX3CR1 upregulation and Ly6C downregulation. In addition, inflammatory monocytes were aggregated inside the collecting venule only at 1 dpn. Neutrophils were not a major type of phagocyte during this response. The gene encoding C-C motif chemokine ligand 2 gene was significantly upregulated as early as 3 h after acoustic overstimulation. Given these results, treatment to control immune response after a noise-induced hearing loss should be applied as soon as possible.

Comparative study of the efficacy and safety of minimally invasive interlaminar full-endoscopic discectomy versus conventional microscopic discectomy in single-level lumbar herniated intervertebral disc (ENDO-F Trial): a multicenter, prospective, randomized controlled trial protocol

Background

Advances in minimally invasive surgery have expanded the indications for interlaminar full-endoscopic discectomy. Although the clinical outcomes for this approach may be equivalent to those of conventional microscopic discectomy, the supporting evidence is still based on small, single-center, prospective, and retrospective studies. Therefore, a multicenter randomized controlled trial is warranted.

Methods

This will be a prospective, multicenter, randomized controlled trial comparing the efficacy and safety of interlaminar full-endoscopic discectomy to those of conventional microscopic discectomy. The trial will enroll 100 participants with a lumbar disc herniation, 50 in each group. The primary outcome will be the Oswestry Disability Index (ODI) score at 12 months post-surgery. Secondary outcomes will be back and leg pain (visual analog scale); the ODI; the EuroQol-5-dimension score; patient satisfaction; and walking distance/time and time to return to daily activities post-surgery. Surgical outcomes will include postoperative drainage, operative time, duration of hospital stay, postoperative creatine kinase level as an indicator of muscle injury, and postoperative scarring. Postoperative magnetic resonance imaging, computed tomography, and simple radiography will be performed to evaluate radiographic outcomes between the two surgical approaches. Surgery-related complications and adverse effects will be evaluated as safety outcomes. A single assessor at each participating hospital, blinded to group allocation, will assess the enrolled participants at baseline, at 2 weeks, and at 3, 6, and 12 months postoperatively.

Discussion

This trial is designed to determine whether interlaminar full-endoscopic discectomy is clinically comparable to microscopic discectomy to treat lumbar disc herniations. All efforts will be made to reduce bias, including adequate sample size, blinded analyses, and multicenter prospective registration. The outcomes will inform practice, providing the evidence needed for using interlaminar full-endoscopic over microscopic discectomy by confirming the potential of this technique to improve patient satisfaction and clinical outcomes.

Trial registration: Clinical Research Information Service; cris.nih.go.kr. (KCT0006277); protocol version (v1, June 8, 2021).

Inflammatory monocytes infiltrate the spiral ligament and migrate to the basilar membrane after noise exposure

Objectives

Noise exposure leads to an increase in the macrophage population. This increment is thought to be caused by the transformation of infiltrated monocytes into macrophages rather than by proliferation of the cochlear resident macrophages. However, studies on infiltrated monocytes in the cochlea are scarce. Thus, we aimed to investigate the infiltration of monocytes and their transformation into macrophages after noise exposure.

Methods

In wild-type and CX3CR1^+/GFP C57/B6 mice, inflammatory monocytes were identified by immunofluorescence of mouse cochlear cells. The findings were confirmed and quantitated by flow cytometry.

Results

One day after noise exposure, monocytes were identified in the spiral ligament. Flow cytometric analysis confirmed that the monocyte population peaked on post-noise exposure day 1 and decreased thereafter. On day 3 after noise exposure, amoeboid-type macrophages increased in the crista basilaris, and on day 5, they spread to the basilar membrane.

Conclusion

Infiltrated monocytes were successfully observed 1 day after noise exposure, preceding the increase in the macrophage population. This finding supports the proposal that infiltrated monocytes transform into macrophages.

Saccular Pathology Is Most Commonly Found in Patients With General Vestibular Disorders

Objectives

The first purpose of this study was to investigate the difference in the frequency of involvement of the superior vestibular nerve (SVN) and inferior vestibular nerve (IVN) territories in general vestibular disorders, and to identify which IVN territory was more commonly involved in patients with IVN lesions. The second purpose was to investigate the correlation of the degree of each saccular and posterior semicircular canal (PSCC) dysfunction, as represented by the parameters of cervical vestibular evoked myogenic potential (cVEMP) and video head impulse test (vHIT), in patients with pathology of the IVN territory.

Methods

In total, 346 patients with dizziness who underwent the caloric test, cVEMP, and vHIT were enrolled. Canal weakness in the caloric test, interaural amplitude difference (IAD) of cVEMP, and vestibulo-ocular reflex gain of the vestibulo-ocular reflex gain of the posterior semicircular canal (p-VOR) in vHIT were analyzed.

Results

Among the enrolled patients, 15.6% had total vestibular nerve dysfunction, 14.5% had solely SVN dysfunction, and 29.5% had solely IVN dysfunction. Isolated saccular pathology was most common in patients with IVN pathology, followed by those with total IVN dysfunction and PSCC dysfunction. IAD and p-VOR were statistically well correlated, and the correlation was strongest in patients with both pathologic IAD and pathologic p-VOR (n=23, r=0.944), followed by patients with normal IAD and pathologic p-VOR (n=27, r=0.762) and patients with pathologic IAD and normal p-VOR (n=106, r=0.339).

Conclusion

Abnormal results were more common in vestibular tests investigating the IVN than in vestibular tests investigating the SVN in patients with general vestibular disorders. Isolated saccular pathology was more frequent than PSCC or combined pathology in patients with IVN dysfunction. Patients with abnormal p-VOR in vHIT had a higher probability of having both saccular and PSCC pathologies than patients with an abnormal IAD. This study describes the characteristics of vestibular-system subregions and provides guidance for clinically interpreting the combination of cVEMP and vHIT results.

Da Vinci SP robotic approach to colorectal surgery: two specific indications and short-term results

BACKGROUND

Da Vinci® Single Port (dvSP) was recently developed. Its application in colorectal surgery is under investigation. The aim of this study was to explore the safety and feasibility of dvSP for intersphincteric (dvSP-ISR), right colectomy (dvSP-RC), and transverse colectomy (dvSP-TC). Surgical indication and short-term results were analyzed.

METHODS

All consecutive patients from a prospective database of patients who underwent dvSP-ISR, dvSP-RC, and dvSP-TC at Korea University Anam Hospital from November 2020 to December 2021, were analyzed. Perioperative, pathological, and oncological short-term outcomes were analyzed.

RESULTS

A total of 7 dvSP-ISR, 5 dvSP-RC, and 1 dvSP-TC were performed. Median age was 56.0 (55.0-61.0) years for the dvSP-ISR and 54.0 (44.7-63.5) years for the dvSP-RC/TC. Median body mass index was 22.8 (17.1-24.8) kg/m² for the dvSP-ISR and 23.6 (20.8-26.9) kg/m² for the dvSP-RC/TC. All dvSP-ISR patients received neoadjuvant long-course chemoradiotherapy, including one patient with squamocellular carcinoma who was treated with 5-fluorouracil (5-FU)/mitomycin. All other patients, excluding one dvSP-RC patient with Crohn's disease, had an adenocarcinoma. Median operation time was 280 (240-370) minutes for the dvSP-ISR and 220 (201-270) minutes for the dvSP-RC/TC. Estimated blood loss was insignificant. No intraoperative complications or conversions to multiport/open surgery was reported. Median post-operative stay was 7.0 (6.0-10.0) days for the dvSP-ISR and 5.0 (4.0-6.7) days for the dvSP-RC/TC. Quality of mesorectum was complete for six patients, and nearly complete for one. Median number of retrieved lymph nodes were 21 (17-25) for the dvSP-ISR and 28 (24-49) for the dvSP-RC/TC. Proximal and distal resection margins were tumor free. Four patients experienced post-operative complications not related to the platform which were: ileus, voiding dysfunction, infected pelvic hematoma, and wound infection. Median follow-up was 9 (6-11) months and 11 (7-17) months for the dvSP-ISR and dvSP-RC/TC, respectively. Two patients had systemic recurrence; all others were tumor free.

CONCLUSIONS

The dvSP platform is safe and feasible for intersphincteric resection with right lower quadrant access, and right/transverse colectomy with suprapubic access. Further studies are needed to evaluate benefit differences compared to multiport robotic platform.

γ-Oryzanol Improves Exercise Endurance and Muscle Strength by Upregulating PPARδ and ERRγ Activity in Aged Mice

SCOPE

γ-Oryzanol, a well-known antioxidant, has been used by body builders and athletes to boost strength and increase muscle gain, without major side effects. However, the effect of γ-Oryzanol on sarcopenia and the underlying molecular mechanism is poorly understood.

RESULTS

Aged mice fed with the γ-Oryzanol diet do not show significant changes in muscle weight, but show increased running endurance as well as improved grip strength. The expression and activity of PPARδ and ERRγ are increased in skeletal muscle of γ-Oryzanol supplemented mice. γ-Oryzanol upregulates oxidative muscle fibers by MEF2 transcription factor, and PGC-1α and ERRα expressions. Fatty acid oxidation related genes and mitochondria biogenesis are upregulated by γ-Oryzanol. In addition, γ-Oryzanol inhibits TGF-β-Smad-NADPH oxidase 4 pathway and inflammatory cytokines such as TNF-α, IL-1β, IL-6, and p65 NF-κB subunit, which cause skeletal muscle weakness. Collectively, γ-Oryzanol attenuates muscle weakness pathway and increases oxidative capacity by increasing PPARδ and ERRγ activity, which contributes to enhance strength and improve oxidative capacity in muscles, consequently enhancing exercise capacity in aged mice. Particularly, γ-Oryzanol directly binds to PPARδ.

CONCLUSIONS

These are the first findings showing that γ-Oryzanol enhances skeletal muscle function in aged mice by regulating PPARδ and ERRγ activity without muscle gain.

Natural Antioxidant and Anti-Inflammatory Compounds in Foodstuff or Medicinal Herbs Inducing Heme Oxygenase-1 Expression

Heme oxygenase-1 (HO-1) is an inducible antioxidant enzyme that catalyzes heme group degradation. Decreased level of HO-1 is correlated with disease progression, and HO-1 induction suppresses development of metabolic and neurological disorders. Natural compounds with antioxidant activities have emerged as a rich source of HO-1 inducers with marginal toxicity. Here we discuss the therapeutic role of HO-1 in obesity, hypertension, atherosclerosis, Parkinson's disease and hepatic fibrosis, and present important signaling pathway components that lead to HO-1 expression. We provide an updated, comprehensive list of natural HO-1 inducers in foodstuff and medicinal herbs categorized by their chemical structures. Based on the continued research in HO-1 signaling pathways and rapid development of their natural inducers, HO-1 may serve as a preventive and therapeutic target for metabolic and neurological disorders.

GSK3β-Mediated Expression of CUG-Translated WT1 Is Critical for Tumor Progression

The Wilms' tumor 1 (WT1) gene is well known as a chameleon gene. It plays a role as a tumor suppressor in Wilms' tumor but also acts as an oncogene in other cancers. Previously, our group reported that a canonical AUG starting site for the WT1 protein (augWT1) acts as a tumor suppressor, whereas a CUG starting site for the WT1 protein (cugWT1) functions as an oncogene. In this study, we report an oncogenic role of cugWT1 in the AOM/DSS-induced colon cancer mouse model and in a urethane-induced lung cancer model in mice lacking cugWT1. Development of chemically-induced tumors was significantly depressed in cugWT1-deficient mice. Moreover, glycogen synthase kinase 3β promoted phosphorylation of cugWT1 at S64, resulting in ubiquitination and degradation of the cugWT1 associated with the F-box^-/- WD repeat-containing protein 8. Overall, our findings suggest that inhibition of cugWT1 expression provides a potential candidate target for therapy. SIGNIFICANCE: These findings demonstrate that CUG-translated WT1 plays an oncogenic role in vivo, and GSK3β-mediated phosphorylation of cugWT1 induces its ubiquitination and degradation in concert with FBXW8.

Feasibility of Asynchronous and Automated Telemedicine in Otolaryngology: Prospective Cross-Sectional Study

BACKGROUND

COVID-19 often causes respiratory symptoms, making otolaryngology offices one of the most susceptible places for community transmission of the virus. Thus, telemedicine may benefit both patients and physicians.

OBJECTIVE

This study aims to explore the feasibility of telemedicine for the diagnosis of all otologic disease types.

METHODS

A total of 177 patients were prospectively enrolled, and the patient's clinical manifestations with otoendoscopic images were written in the electrical medical records. Asynchronous diagnoses were made for each patient to assess Top-1 and Top-2 accuracy, and we selected 20 cases to conduct a survey among four different otolaryngologists to assess the accuracy, interrater agreement, and diagnostic speed. We also constructed an experimental automated diagnosis system and assessed Top-1 accuracy and diagnostic speed.

RESULTS

Asynchronous diagnosis showed Top-1 and Top-2 accuracies of 77.40% and 86.44%, respectively. In the selected 20 cases, the Top-2 accuracy of the four otolaryngologists was on average 91.25% (SD 7.50%), with an almost perfect agreement between them (Cohen kappa=0.91). The automated diagnostic model system showed 69.50% Top-1 accuracy. Otolaryngologists could diagnose an average of 1.55 (SD 0.48) patients per minute, while the machine learning model was capable of diagnosing on average 667.90 (SD 8.3) patients per minute.

CONCLUSIONS

Asynchronous telemedicine in otology is feasible owing to the reasonable Top-2 accuracy when assessed by experienced otolaryngologists. Moreover, enhanced diagnostic speed while sustaining the accuracy shows the possibility of optimizing medical resources to provide expertise in areas short of physicians.

HI-511 overcomes melanoma drug resistance via targeting AURKB and BRAF V600E

Rationale: Melanoma is an aggressive tumor of the skin and drug resistance is still a major problem in melanoma therapy. Novel targets and effective agents to overcome drug resistant melanoma are urgently needed in clinical therapy.

Methods: Gene Expression Omnibus (GEO) database analysis, pathway enrichment analysis, and survival rate analysis were utilized to identify a candidate target. An anchorage-independent cell growth assay, flow cytometry, Western blot, and a xenograft mouse model were used to study the function of Aurora kinase B (AURKB) in both drug-sensitive and drug-resistant melanoma. Next, HI-511, a novel dual-target inhibitor targeting both AURKB and BRAF V600E, was designed and examined by an in vitro kinase assay. Methods as indicated above in addition to a BRAF V600E/PTEN-loss melanoma mouse model were used to demonstrate the effect of HI-511 on melanoma development in vitro and in vivo.

Results: AURKB is highly expressed in melanoma and especially in vemurafenib-resistant melanoma and the expression was correlated with patient survival rate. Knocking down AURKB inhibited cell growth and induced apoptosis in melanoma, which was associated with the BRAF/MEK/ERKs and PI3-K/AKT signaling pathways. Importantly, we found that HI-511, a novel dual-target inhibitor against AURKB and BRAF V600E, suppresses both vemurafenib-sensitive and vemurafenib-resistant melanoma growth in vitro and in vivo by inducing apoptosis and mediating the inhibition of the BRAF/MEK/ERKs and PI3K/AKT signaling pathways.

Conclusion: AURKB is a potential target for melanoma treatment. HI-511, a novel dual-target inhibitor against both AURKB and BRAF V600E, could achieve durable suppression of melanoma growth, even drug-resistant melanoma growth.

Synthetic lethality by targeting the RUVBL1/2-TTT complex in mTORC1-hyperactive cancer cells

Despite considerable efforts, mTOR inhibitors have produced limited success in the clinic. To define the vulnerabilities of mTORC1-addicted cancer cells and to find previously unknown therapeutic targets, we investigated the mechanism of piperlongumine, a small molecule identified in a chemical library screen to specifically target cancer cells with a hyperactive mTORC1 phenotype. Sensitivity to piperlongumine was dependent on its ability to suppress RUVBL1/2-TTT, a complex involved in chromatin remodeling and DNA repair. Cancer cells with high mTORC1 activity are subjected to higher levels of DNA damage stress via c-Myc and displayed an increased dependency on RUVBL1/2 for survival and counteracting genotoxic stress. Examination of clinical cancer tissues also demonstrated that high mTORC1 activity was accompanied by high RUVBL2 expression. Our findings reveal a previously unknown role for RUVBL1/2 in cell survival, where it acts as a functional chaperone to mitigate stress levels induced in the mTORC1-Myc-DNA damage axis.

CDK12 and PAK2 as novel therapeutic targets for human gastric cancer

Background: Gastric cancer remains the second leading cause of cancer-related death, and the third in mortality due to lack of effective therapeutic targets for late stage cancer patients. This study aims to identify potential druggable target biomarkers as potential therapeutic options for patients with gastric cancer.

Methods: Immunohistochemistry of human gastric tumor tissues was conducted to determine the expression level of cyclin-dependent kinase 12 (CDK12). Multiple in vitro and in vivo assays such as RNAi, mass spectrometry, computer docking models, kinase assays, cell xenograft NU/NU mouse models (CDXs) and patient-derived xenograft NOD/SCID mouse models (PDXs) were conducted to study the function and molecular interaction of CDK12 with p21 activated kinase 2 (PAK2), as well as to find CDK12 inhibitors as potential treatment options for human gastric cancer.

Results: Here we identified that CDK12 is a driver gene in human gastric cancer growth. Mechanistically, CDK12 directly binds to and phosphorylates PAK2 at T134/T169 to activate MAPK signaling pathway. We further identified FDA approved clinical drug procaterol can serve as an effective CDK12 inhibitor, leading to dramatic restriction of cancer cell proliferation and tumor growth in human gastric cancer cells and PDXs.

Conclusions: Our data highlight the potential of CDK12/PAK2 as therapeutic targets for patients with gastric cancer, and we propose procaterol treatment as a novel therapeutic strategy for human gastric cancer.

Machine learning approach for prediction of hearing preservation in vestibular schwannoma surgery

In vestibular schwannoma patients with functional hearing status, surgical resection while preserving the hearing is feasible. Hearing levels, tumor size, and location of the tumor have been known to be candidates of predictors. We used a machine learning approach to predict hearing outcomes in vestibular schwannoma patients who underwent hearing preservation surgery: middle cranial fossa, or retrosigmoid approach. After reviewing the medical records of 52 patients with a pathologically confirmed vestibular schwannoma, we included 50 patient’s records in the study. Hearing preservation was regarded as positive if the postoperative hearing was within serviceable hearing (50/50 rule). The categorical variable included the surgical approach, and the continuous variable covered audiometric and vestibular function tests, and the largest diameter of the tumor. Four different algorithms were lined up for comparison of accuracy: support vector machine(SVM), gradient boosting machine(GBM), deep neural network(DNN), and diffuse random forest(DRF). The average accuracy of predicting hearing preservation ranged from 62% (SVM) to 90% (DNN). The current study is the first to incorporate machine learning methodology into a prediction of successful hearing preservation surgery. Although a larger population may be needed for better generalization, this study could aid the surgeon’s decision to perform a hearing preservation approach for vestibular schwannoma surgery.

NCM 1921, a Mixture of Several Ingredients, Including Fatty Acids and Choline, Attenuates Atopic Dermatitis in 1-Chloro-2,4-Dinitrobenzene-Treated NC/Nga Mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease in humans. In this study, we evaluated the effects of a mixture (NCM 1921) of omega-3 butter, omega-3 beef tallow oil, omega-3 lard oil, caprylic acid, lauric acid, choline, and Fe on AD in 1-chloro-2,4-dinitrobenzene (DNCB)-treated NC/Nga mice. NCM 1921 significantly ameliorated the macroscopic and microscopic signs and reduced skin thickness and mast cell incorporation in the skin lesions of mice with DNCB-induced AD. Furthermore, it reduced serum immunoglobulin E levels; reduced the number of IgE-producing B cells, peripheral blood mononuclear cells, white blood cells, and differential white blood cells; and increased the number of lymphocytes. NCM 1921 normalized the total cell number in dorsal skin tissue, the axillary lymph node, and spleen following DNCB exposure and reduced the number of CD23+/B220+ cells in the axillary lymph node and CD3+ cells in dorsal skin tissue. Moreover, it reduced the levels of interleukin (IL)-4 and IL-13 but increased the levels of interferon-γ in anti-CD3–stimulated splenocytes. Immunohistofluorescence staining showed that NCM 1921 treatment significantly increased claudin1, filaggrin, and Sirt1 protein expressions in AD skin lesions. These results suggest that NCM 1921 could be a valuable remedy for the treatment of AD.

Abstract C013: HI-B9 suppresses colorectal cancer by inhibiting Wnt/β-catenin pathway

Deregulated Wnt/β-catenin pathway plays an important role in colorectal cancer. β-Catenin interacts with transcription factor 7-like 2 (TCF7L2 or TCF4) to express oncogenes including c-myc, axin2 and cyclin D1. Here we describe a small molecule, referred to as HI-B9, which inhibits the growth of colorectal cancer cell lines. HI-B9 suppressed tryptophan fluorescence of β-catenin that contains TCF4-binding residues. In silico docking of HI-B9 on β-catenin showed a binding mode that blocks Lys 312 residue which is critical for the interaction between β-catenin and its interactors. A binding assay showed that the binding affinity of HI-B9 against β-catenin G307A/K312E mutant was significantly reduced compared to that against wildtype. HI-B9 inhibited β-catenin/TCF4 luciferase activity in a dose-dependent manner. Anchorage-independent growth of HCT116 and HT29 colorectal cancer cells were suppressed by the small molecule. mRNA expression levels of Wnt target genes were reduced by HI-B9 treatment. HI-B9 did not affect the translocation of β-catenin toward the nucleus. The therapeutic effects of HI-B9 was due to the disruption of β-catenin/TCF4 complex formation ex vivo. Our findings demonstrate the therapeutic potential of HI-B9 against colorectal cancer with aberrant Wnt/β-Catenin signaling pathway.

Citation Format: Seung Ho Shin, Kanamata Reddy, Zigang Dong. HI-B9 suppresses colorectal cancer by inhibiting Wnt/β-catenin pathway [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C013. doi:10.1158/1535-7163.TARG-19-C013

Management of isolated recurrence after surgery for pancreatic adenocarcinoma

BACKGROUND

Recurrence of pancreatic cancer after primary pancreatectomy occurs in the vast majority of patients. The role of surgical treatment for recurrent pancreatic cancer is not well established.

METHODS

Patients who underwent primary pancreatectomy with curative intent from 2000 to 2014 at a single large-volume centre were evaluated retrospectively. CT or PET was used to select patients with an isolated recurrence. The clinicopathological features and survival outcomes were compared according to treatment modalities.

RESULTS

Of the 1610 patients with pancreatic cancer who underwent resection, 1346 (83·6 per cent) were diagnosed with recurrent pancreatic cancer. Recurrence was locoregional in 366 patients (27·2 per cent), distant multifocal in 251 (18·6 per cent), distant isolated in 188 (14·0 per cent), locoregional plus distant in 153 (11·4 per cent) and peritoneal seeding in 388 (28·8 per cent). Of the 1346 patients with recurrence, 197 (14·6 per cent) had isolated recurrence; of these, 48 (24·4 per cent of all isolated recurrences; 3·6 per cent of all recurrences) underwent resection. Median survival of the 197 patients after diagnosis of isolated recurrence was 14·7 months; it was longer in patients who underwent surgical resection than among those treated non-surgically (23·5 versus 12·0 months; P = 0·014). Multivariable analysis showed that chemotherapy and resection for recurrence were associated with better prognosis. Median survival after recurrence was longest in the 23 patients with isolated pulmonary recurrence (33·3 months). Survival after recurrence was better in patients who underwent resection of isolated recurrence in the remnant pancreas (median 28·0 versus 12·0 months, P = 0·010) and lung (median 36·5 versus 9·5 months; P = 0·010) than in those who did not undergo resection.

CONCLUSION

Surgical resection may be considered an option for treatment of patients with isolated recurrent pancreatic cancer.

Abstract 1113: Targeting PRPK function blocks colon cancer metastasis

The biological functions of the p53-related protein kinase (PRPK) remain unclear. We have previously demonstrated that PRPK is phosphorylated by the T-LAK cell-originated protein kinase (TOPK) and that phosphorylated PRPK (p-PRPK) promotes colon cancer metastasis. Here, we analyzed colon adenocarcinomas from 87 patients and found that higher expression levels of p-PRPK were associated with later stages of metastatic dissemination (stage III and IV) as compared with earlier stages (stages I and II). Indeed, levels of p-PRPK were higher in metastatic versus malignant human colon adenocarcinomas. Knocking down PRPK expression attenuated colorectal liver and lung metastasis of colon cancer cells in vivo. An in vitro kinase assay indicated that active PRPK does not phosphorylate p53 directly. We found that PRPK phosphorylates survivin, a regulator of colon cancer metastasis. PRPK phosphorylates survivin at Thr34, which is important for survivin stability. Taken together, our data strongly suggest that the PRPK signaling pathway promotes colon cancer metastasis by modulating survivin stability, and that PRPK could be a new prognostic marker for the survival of colon cancer patients. In addition, we identified an FDA-approved bacteriostatic antibiotic, fusidic acid sodium salt (fusidic acid or FA) as an inhibitor of PRPK, and show that FA combined with 5-fluorouracil (5-FU) inhibited PRPK activity and colon cancer metastasis to the lung in mice. We contend that the combination of FA with 5-FU could be an alternative therapeutic strategy to traditional chemotherapy for colon cancer patients with poor prognosis.

Citation Format: Tatyana Zykova, Ke Yao, Seung Ho Shin, Eunmiri Roh, Weiya Ma, Ann M. Bode, Zigang Dong. Targeting PRPK function blocks colon cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1113.

Abstract 3839: A small-molecule inhibitor of the β-catenin-TCF4 interaction suppresses colorectal cancer growth in vitro and in vivo

Colorectal cancer is associated with aberrant activation of the Wnt pathway. β-Catenin plays essential roles in the Wnt pathway by interacting with T-cell factor 4 (TCF4) to transcribe oncogenes. We synthesized a small molecule, referred to as HI-B1, and evaluated signaling changes and biologic consequences induced by the compound. HI-B1 inhibited β-catenin/TCF4 luciferase activity and preferentially caused apoptosis of cancer cells in which the survival is dependent on β-catenin. The formation of the β-catenin/TCF4 complex was disrupted by HI-B1 due to the direct interaction of HI-B1 with β-catenin. Colon cancer patient-derived xenograft (PDX) studies showed that a tumor with higher levels of β-catenin expression was more sensitive to HI-B1 treatment, compared to a tumor with lower expression levels of β-catenin. The different sensitivities of PDX tumors to HI-B1 were dependent on the β-catenin expression level and potentially could be further exploited for biomarker development and therapeutic applications against colon cancer.

Citation Format: Seung Ho Shin, Do Young Lim, Kanamata Reddy, Margarita Malakhova, Fangfang Liu, Ting Wang, Mengqiu Song, Hanyong Chen, Ki Beom Bae, Joohyun Ryu, Kangdong Liu, Mee-Hyun Lee, Ann M. Bode, Zigang Dong. A small-molecule inhibitor of the β-catenin-TCF4 interaction suppresses colorectal cancer growth in vitro and in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3839.

Trans-tympanic Cartilage Chip Insertion for Intractable Patulous Eustachian Tube

Background and Objectives

Patulous Eustachian tube (PET) causes troublesome autophony. We treated PET using tragal cartilage chip insertion to fill in the concavity within the tubal valve and evaluated the feasibility of this method.

Subjects and Methods

This study used a prospective design. Eleven patients with PET disorder were included. Tragal cartilage chip insertion via a transcanal approach into the Eustachian tube (ET) was performed in 14 ears of those patients. They were followed-up for at least 12 months after surgery and were evaluated by symptom questionnaire scores.

Results

The average follow-up was 16.4 months. Thirteen of fourteen ears received immediate complete relief of autophony symptoms. Autophony symptoms at the last follow-up were as follows: four ears (28.6%) had complete relief; five ears (35.7%) showed satisfactory improvement; four ears (28.6%) showed significant but unsatisfactory improvement; and one ear (7.1%) was unchanged. The PET symptom questionnaire in the affected ears showed a significant reduction in autophony (p=0.047) and improvement in breathing sound conduction (p=0.047). There were no complications such as otitis media or occlusion symptom.

Conclusions

Transtympanic cartilage chip insertion into the ET provides a safe and accessible surgical option for the treatment of PET.

Orthopedic injuries associated with jet-skis (personal watercrafts): A review of 127 inpatients

BACKGROUND

Personal watercrafts (PWC) account for a disproportionate amount of water based injuries. Current literature suggests those with less PWC experience are more at risk for injury. Previous studies have not specifically evaluated the orthopedic implications of PWC usage or how various mechanisms of injury (MOI) contribute to different injury patterns.

HYPOTHESIS

PWC injuries will frequently require orthopedic intervention. The presence of an orthopedic injury will result in increased injury severity score (ISS), hospital and intensive care unit (ICU) length of stay (LOS). Patients visiting our region will have less PWC experience and so are more prone to serious injuries.

MATERIALS AND METHODS

Retrospective cohort study at a single Level 1 trauma center of admitted patients sustaining PWC injuries from 02/2004-03/2017. The following were studied: demographics, mechanism, season, ISS, hospital and ICU LOS, follow-up, fracture characteristics and management.

RESULTS

Hundred and twenty-seven patients were admitted due to PWC injury, 66 (52.0%) sustained an orthopedic injury, totaling 103 fractures (48 [46.6%] lower extremity, 26 [25.2%] upper extremity, 14 [13.6%] vertebral, 11 [10.7%] pelvic ring and 4 [3.9%] acetabulum). The mean age of orthopedic patients was 29 years (range 8-62). Handle bar injuries were significantly associated with open fractures, (13 of 25 open fractures, 3 of which became infected). Injuries occurring during the winter were associated with a higher ISS, yet more injuries occurred in the summer. A patient being a "visitor" to the region did not influence ISS. The mean LOS was 12.6 days for orthopedic patients. Eighteen orthopedic patients (27.3%) required ICU admission and 36 (54.5%) patients required orthopedic surgery (mean 2.11 operations).

DISCUSSION

A majority of PWC injuries resulted in extremity fractures with a moderate percentage requiring orthopedic surgery. Correlations between PWC experience and injury incidence can provide information for increased safety.

LEVEL OF EVIDENCE

IV; retrospective.

Targeting PRPK Function Blocks Colon Cancer Metastasis

The biological functions of the p53-related protein kinase (PRPK) remain unclear. We have previously demonstrated that PRPK is phosphorylated by the T-LAK cell-originated protein kinase (TOPK) and that phosphorylated PRPK (p-PRPK) promotes colon cancer metastasis. Here, we analyzed colon adenocarcinomas from 87 patients and found that higher expression levels of p-PRPK were associated with later stages of metastatic dissemination (stage III and IV) as compared with earlier stages (stages I and II). Indeed, levels of p-PRPK were higher in metastatic versus malignant human colon adenocarcinomas. Knocking down PRPK expression attenuated colorectal liver and lung metastasis of colon cancer cells in vivo An in vitro kinase assay indicated that active PRPK does not phosphorylate p53 directly. We found that PRPK phosphorylates survivin, a regulator of colon cancer metastasis. PRPK phosphorylates survivin at Thr34, which is important for survivin stability. Taken together, our data strongly suggest that the PRPK signaling pathway promotes colon cancer metastasis by modulating survivin stability, and that PRPK could be a new prognostic marker for the survival of colon cancer patients. In addition, we identified an FDA-approved bacteriostatic antibiotic, fusidic acid sodium salt (fusidic acid or FA) as an inhibitor of PRPK, and show that FA combined with 5-fluorouracil (5-FU) inhibited PRPK activity and colon cancer metastasis to the lung in mice. We contend that the combination of FA with 5-FU could be an alternative therapeutic strategy to traditional chemotherapy for colon cancer patients with poor prognosis. Mol Cancer Ther; 17(5); 1101-13. ©2018 AACR.

Effect of the sexual abstinence period recommended by the World Health Organization on clinical outcomes of fresh embryo transfer cycles with normal ovarian response after intracytoplasmic sperm injection

This study was to investigate whether the sexual abstinence period (SAP) recommended by the World Health Organization (WHO) affects clinical outcomes. We compared the rate of clinical outcomes between 2-7 and ≥8 days of SAP in first fresh embryo transfer after intracytoplasmic sperm injection (ICSI) in groups of young maternal age (YMA: <38 years) and old maternal age (OMA: ≥38 years). We conducted a retrospective study of 449 first ICSI cycles with a normal ovarian response. SAP was identified before collecting the semen samples. Semen analysis was performed based on the guidelines recommended by WHO (2010). Sperm preparation was made using the swim-up method. Patients' baseline characteristics in the YMA and OMA groups did not differ. The rates of fertilisation, top-quality embryos on day 3, biochemical pregnancy, clinical pregnancy, ongoing pregnancy, abortion and implantation per cycle were not significantly different between 2-7 and ≥8 days of SAP in the YMA or OMA group. In conclusion, SAP beyond the recommended period by WHO was not associated with the rates of a lower fertilisation and pregnancy in human in vitro fertilisation (IVF). We think that a new criterion of SAP for clinical application in human IVF needs to be considered by WHO.

A Small Molecule Inhibitor of the β-Catenin-TCF4 Interaction Suppresses Colorectal Cancer Growth In Vitro and In Vivo

Colorectal cancer is associated with aberrant activation of the Wnt pathway. β-Catenin plays essential roles in the Wnt pathway by interacting with T-cell factor 4 (TCF4) to transcribe oncogenes. We synthesized a small molecule, referred to as HI-B1, and evaluated signaling changes and biological consequences induced by the compound. HI-B1 inhibited β-catenin/TCF4 luciferase activity and preferentially caused apoptosis of cancer cells in which the survival is dependent on β-catenin. The formation of the β-catenin/TCF4 complex was disrupted by HI-B1 due to the direct interaction of HI-B1 with β-catenin. Colon cancer patient-derived xenograft (PDX) studies showed that a tumor with higher levels of β-catenin expression was more sensitive to HI-B1 treatment, compared to a tumor with lower expression levels of β-catenin. The different sensitivities of PDX tumors to HI-B1 were dependent on the β-catenin expression level and potentially could be further exploited for biomarker development and therapeutic applications against colon cancer.

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HI-B1 is a synthesized compound identified as a β-catenin inhibitor suppressing the β-catenin-TCF4 protein interaction.

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HI-B1 preferentially causes apoptosis in β-catenin-dependent cancer cells.

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A colon cancer PDX mouse model with a high level of β-catenin is sensitive to HI-B1.

β-catenin is an important protein that facilitates colon cancer. Shin et al. synthesized and identified HI-B1 as a direct β-catenin inhibitor. HI-B1 disrupted formation of the β-catenin-TCF4 protein complex. HI-B1 preferentially caused apoptosis of cancer cells in which the survival is dependent on β-catenin. In a comparison of two colon cancer PDX models with different β-catenin levels, they showed that β-catenin-high PDX is more sensitive to HI-B1 treatment than β-catenin-low PDX. HI-B1 could thus be further developed as a colon cancer drug, and β-catenin expression levels might be a predictive biomarker for colon cancer therapy using β-catenin inhibitors.

Tracheal reconstruction with a free vascularized myofascial flap: preclinical investigation in a porcine model to human clinical application

Although there are various methods for tracheal reconstruction, such as a simple approximation with suturing and coverage with adjacent soft tissue or muscle, large defects >50% of the tracheal length still present a clinical challenge. Tissue engineering, a recent promising way to possibly resolve this problem, requires a long preparatory period for stem cell seeding on a scaffold and relatively invasive procedures for stem cell harvesting. As an alternative, we used a vascularized myofascial flap for tracheal reconstruction. In four porcine models, the deep inferior epigastric perforator (DIEP) was used in two and the superior epigastric artery perforator (SEAP) in two. Transformation of the surface of the transplanted myofascial flap was analyzed in the airway environment. The flaps failed in the DIEP group due to venous congestion. At 12 weeks postoperatively, none of SEAP group showed any signs of respiratory distress; the inner surface of the implant exhibited stratified squamous epithelium with sparse cilia. In the clinical setting, a patient who underwent a tracheal reconstruction with a vascularized myofascial flap and 2-year follow-up was in good health with no respiratory distress symptoms.

Caffeic Acid Phenethyl Ester from the Twigs of Cinnamomum cassia Inhibits Malignant Cell Transformation by Inducing c-Fos Degradation

The twigs of Cinnamomum cassia, commonly referred to as Cinnamomi Ramulus, are widely used as one of the primary ingredients in Chinese/Korean traditional medicines that have anticancer effects. However, the active constituents responsible for its anticancer effects and their molecular mechanisms still remain to be elucidated. Caffeic acid phenethyl ester (CAPE) and caffeic acid (CA) were isolated for the first time from C. cassia using LC-MS-guided phytochemical isolation methods. CAPE significantly suppressed EGF- and TPA-induced cell transformation of JB6 P+ cells at sub-micromolar concentrations, whereas CA, a structurally similar compound to CAPE, had no such effect. The antiproliferative and chemopreventive activity of CAPE was found to arise through the inhibition of AP-1 transcriptional activity via the promotion of c-Fos degradation. These findings demonstrate that CAPE may contribute to the chemopreventive/chemotherapeutic effects of C. cassia through downregulating c-Fos.

Monitoring rate and predictability of intraoperative monitoring in patients with intradural extramedullary and epidural metastatic spinal tumors

STUDY DESIGN

Single-center retrospective study.

OBJECTIVES

To evaluate the monitoring rate, sensitivity and specificity of intraoperative monitoring (IOM) during removal of intradural extramedullary (IDEM) or epidural metastatic spinal tumors. Also, to assess the efficacy of monitoring somatosensory-evoked potentials (SSEP) when motor-evoked potentials (MEP) are not measurable.

SETTING

The Neuro-Oncology Clinic, National Cancer Center, Korea.

METHODS

Patients (n=101) with IDEM or epidural metastatic spinal tumors at the cord level underwent surgeries monitored with SSEP and/or MEP. The monitoring rate was defined as negative when MEP or SSEP could not be measured after reversal of the neuromuscular block under general anesthesia. Positive IOM changes included more than a 50% change in the MEP or SSEP amplitude and more than a 10% delay in SSEP latency.

RESULTS

MEP was measurable in 73% of patients. The MEP monitoring rate in patients with motor power grades of 3 or less was 39%, which was lower than that of SSEP (83%). The sensitivity, specificity and predictability of MEP for motor changes were 93, 90 and 91%, respectively. Conversely, the sensitivity, specificity and predictability of SSEP were 62, 97 and 89%, respectively. In patients in whom MEP was not measurable (n=24), SSEP was monitored with a predictability of 83%.

CONCLUSION

In cases of extramedullary spinal tumors, MEP shows a higher sensitivity than SSEP does. However, the monitoring rate of MEP in non-ambulatory patients was lower than that of SSEP. In those cases, SSEP can be useful to monitor for postoperative neurological deficits.

Abstract 821: Discovery of catechol moiety-containing natural compounds as direct ERK2 inhibitors by in vitro kinase assay and co-crystallography

Catechol (pyrocathechol, 1,2-dihydroxybenzene) is a chemical that is used by industry in the manufacture of certain products. Many natural compounds contain catechol as a functional group found in various fruits and vegetables such as apple, apricot, grape, bananas, soybean, peanut, pear, plum, mango, avocado, and mushroom. Extracellular signal-regulated kinase 2 (ERK2), a protein kinase that belongs to MAPK family, modulates many important functions such as cell growth, apoptosis and transcriptional regulation in cancer. The expression levels of ERK2 mRNA and protein are reportedly very high in many human cancers, including leukemia, colon, breast, lung and skin cancer. Previously, we reported that norathyriol and caffeic acid, which possess the catechol moiety, and catechol itself directly bind and inhibit ERK2 kinase activity. Those findings led us to test catechol moiety-containing natural compounds, luteolin, quercetin, fisetin, 7,3’,4’-trihydroxyisoflavone, and cyanidin, against ERK2 kinase activity. We found that all of these compounds directly bind to ERK2 and inhibit its activity. We further confirmed the results by resolving a co-crystal structure of ERK2 bound with luteolin in the ATP binding site. To apply this finding to cancer, the effect of the compounds was tested on the K562 human myelogenous leukemia cell line where ERK2 is highly expressed and knock-down of the protein reduced anchorage-independent growth. Five newly-found ERK2 inhibitors (luteolin, quercetin, fisetin, 7,3’,4’-trihydroxyisoflavone and cyanidin) and three known ERK2 inhibitors (norathyriol, caffeic acid and catechol) decreased cell viability of K562 at 40 ìM. When the eight compounds were used at the same dose in combination (5 ìM each and 40 ìM total), the mixture inhibited ERK2 and reduced cell viability of K562 cells. In summary, using in vitro kinase assays and co-crystallography, we identified new ERK2 inhibitors that contain the catechol functional group, and showed anti-cancer effects of the compounds by cell viability assay and soft agar assay. This work impacts the cancer prevention community by showing that many natural compounds can work together targeting ERK2, an important target in cancer.

Citation Format: Seung Ho Shin, Margarita Malakhova, Igor Kurinov, Do Young Lim, Ann M. Bode, Zigang Dong. Discovery of catechol moiety-containing natural compounds as direct ERK2 inhibitors by in vitro kinase assay and co-crystallography. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 821.

A natural small molecule, catechol, induces c-Myc degradation by directly targeting ERK2 in lung cancer

Various carcinogens induce EGFR/RAS/MAPK signaling, which is critical in the development of lung cancer. In particular, constitutive activation of extracellular signal-regulated kinase 2 (ERK2) is observed in many lung cancer patients, and therefore developing compounds capable of targeting ERK2 in lung carcinogenesis could be beneficial. We examined the therapeutic effect of catechol in lung cancer treatment. Catechol suppressed anchorage-independent growth of murine KP2 and human H460 lung cancer cell lines in a dose-dependent manner. Catechol inhibited ERK2 kinase activity in vitro, and its direct binding to the ERK2 active site was confirmed by X-ray crystallography. Phosphorylation of c-Myc, a substrate of ERK2, was decreased in catechol-treated lung cancer cells and resulted in reduced protein stability and subsequent down-regulation of total c-Myc. Treatment with catechol induced G1 phase arrest in lung cancer cells and decreased protein expression related to G1-S progression. In addition, we showed that catechol inhibited the growth of both allograft and xenograft lung cancer tumors in vivo. In summary, catechol exerted inhibitory effects on the ERK2/c-Myc signaling axis to reduce lung cancer tumor growth in vitro and in vivo, including a preclinical patient-derived xenograft (PDX) model. These findings suggest that catechol, a natural small molecule, possesses potential as a novel therapeutic agent against lung carcinogenesis in future clinical approaches.

Sulforaphene suppresses growth of colon cancer-derived tumors via induction of glutathione depletion and microtubule depolymerization

SCOPE

Cruciferous vegetables harbor a number of isothiocyanates that have been recognized for their cancer-related properties. Out of these, sulforaphene (a naturally occurring derivative of sulforaphane) has received little attention in studies of colon cancer and its mechanism of action remains to be elucidated.

METHODS AND RESULTS

We observed that sulforaphene inhibited growth of human colon cancer cell lines HCT116, HT-29, KM12, SNU-1040, and DLD-1, while exhibiting negligible toxicity toward nonmalignant cells. Sulforaphene induced G2/M phase cell cycle arrest and apoptosis of colon cancer cells analyzed by flow cytometry, concomitant with phosphorylation of CDK1 and CDC25B at inhibitory sites, and upregulation of the p38 and JNK pathways. It was further determined that sulforaphene is a potent inhibitor of microtubule polymerization while generating reactive oxygen species via the depletion of glutathione. These observations further extended into inhibitory effects against colon tumor growth in a mouse xenograft model.

CONCLUSION

These findings demonstrate that sulforaphene may contribute to the anti-tumor effects of cruciferous vegetables that contain sulforaphene and other isothiocyanates.

The retinoic acid derivative, ABPN, inhibits pancreatic cancer through induction of Nrdp1

Combination chemotherapy for the treatment of pancreatic cancer commonly employs gemcitabine with an EGFR inhibitor such as erlotinib. Here, we show that the retinoic acid derivative, ABPN, exhibits more potent anticancer effects than erlotinib, while exhibiting less toxicity toward noncancerous human control cells. Low micromolar concentrations of ABPN induced apoptosis in BxPC3 and HPAC pancreatic cancer cell lines, concomitant with a reduction in phosphorylated EGFR as well as decreased ErbB3, Met and BRUCE protein levels. The degradation of ErbB3 is a result of proteasomal degradation, possibly due to the ABPN-dependent upregulation of Nrdp1. Administration of ABPN showed significant reductions in tumor size when tested using a mouse xenograft model, with higher potency than erlotinib at the same concentration. Analysis of the tumors demonstrated that ABPN treatment suppressed ErbB3 and Met and induced Nrdp1 in vivo. The data suggest that ABPN may be more suitable in combination chemotherapy with gemcitabine than the more widely used EGFR inhibitor, erlotinib.

Genetic ablation of caspase-7 promotes solar-simulated light-induced mouse skin carcinogenesis: the involvement of keratin-17

Solar ultraviolet irradiation is an environmental carcinogen that causes skin cancer. Caspase-7 is reportedly expressed at reduced levels in many cancers. The present study was designed to examine the role of caspase-7 in solar-simulated light (SSL)-induced skin cancer and to elucidate its underlying molecular mechanisms. Our study revealed that mice with genetic deficiency of caspase-7 are highly susceptible to SSL-induced skin carcinogenesis. Epidermal hyperplasia, tumor volume and the average number of tumors were significantly increased in caspase-7 knockout (KO) mice compared with SKH1 wild-type mice irradiated with SSL. The expression of cell proliferation markers, such as survivin and Ki-67, was elevated in SSL-irradiated skin of caspase-7 KO mice compared with those observed in SSL-exposed wild-type SKH1 mouse skin. Moreover, SSL-induced apoptosis was abolished in skin from caspase-7 KO mice. Two-dimensional gel electrophoresis, followed by matrix-assisted laser desorption/ionization-time-of-flight analysis of skin tissue lysates from SSL-irradiated SKH1 wild-type and caspase-7 KO mice revealed an aberrant induction of keratin-17 in caspase-7 KO mice. Immunohistochemical analysis of skin tumors also showed an increase of keratin-17 expression in caspase-7 KO mice compared with SKH1 wild-type mice. The expression of keratin-17 was also elevated in SSL-irradiated caspase-7 KO keratinocytes as well as in human basal cell carcinomas. The in vitro caspase activity assay showed keratin-17 as a substrate of caspase-7, but not caspase-3. Overall, our study demonstrates that genetic loss of caspase-7 promotes SSL-induced skin carcinogenesis by blocking caspase-7-mediated cleavage of keratin-17.

Identification of a Dual Inhibitor of Janus Kinase 2 (JAK2) and p70 Ribosomal S6 Kinase1 (S6K1) Pathways

Bioactive phytochemicals can suppress the growth of malignant cells, and investigation of the mechanisms responsible can assist in the identification of novel therapeutic strategies for cancer therapy. Ginger has been reported to exhibit potent anti-cancer effects, although previous reports have often focused on a narrow range of specific compounds. Through a direct comparison of various ginger compounds, we determined that gingerenone A selectively kills cancer cells while exhibiting minimal toxicity toward normal cells. Kinase array screening revealed JAK2 and S6K1 as the molecular targets primarily responsible for gingerenone A-induced cancer cell death. The effect of gingerenone A was strongly associated with relative phosphorylation levels of JAK2 and S6K1, and administration of gingerenone A significantly suppressed tumor growth in vivo. More importantly, the combined inhibition of JAK2 and S6K1 by commercial inhibitors selectively induced apoptosis in cancer cells, whereas treatment with either agent alone did not. These findings provide rationale for dual targeting of JAK2 and S6K1 in cancer for a combinatorial therapeutic approach.

Abstract 2601: A natural small molecule, catechol, induces c-Myc degradation by directly targeting ERK2 in lung cancer in vitro and in vivo

For decades, lung cancer has been a leading cause of death in the U.S., mainly due to oncogenic signaling pathways activated by carcinogens such as smoking. Various carcinogens induce EGFR/RAS/MAPK signaling that is critical in the development of lung cancer. In particular, constitutive activation of extracellular signal-regulated kinase 2 (ERK2) is observed in many lung cancer patients, and therefore developing compounds capable of targeting ERK2 against lung carcinogenesis will be beneficial to these patients. Herein, we examined the therapeutic effects of catechol (also known as pyrocatechol or 1,2-dihydroxybenzene), a naturally occurring chemical in many foods such as apple, banana, apricot, grape, plum, avocado and mushroom. Co-crystallography results suggested that ERK2 is a direct target of catechol. In agreement with the co-crystallography result, catechol was confirmed to inhibit ERK2 kinase activity in vitro. Catechol inhibited anchorage-independent KP2 and H460 lung cancer cell growth in a dose-dependent manner. Phosphorylation of c-Myc, a substrate of ERK2, was reduced in catechol-treated lung cancer cells compared to untreated controls. Decreased c-Myc phosphorylation resulted in its reduced protein stability and subsequent down-regulation of total c-Myc levels. Treatment with catechol induced G1 cell cycle arrest and resulted in a decrease of G1 phase related proteins, CDK2 and cyclin D1. In vivo study results also revealed that catechol inhibited growth of KP2 and H460 xenograft tumors. Phosphorylation levels of c-Myc were also strongly decreased by catechol treatment in vivo. Taken together, we have shown that catechol exerts inhibitory effects on the ERK2/c-Myc signaling axis in lung cancer cells to reduce tumor growth in vitro and in vivo. These findings suggest that catechol, a natural small molecule, possesses potential as a novel therapeutic agent against lung carcinogenesis.

Citation Format: Do Young Lim, Seung Ho Shin, Margarita Malakhova, Mee-Hyun Lee, Ann M. Bode, Zigang Dong. A natural small molecule, catechol, induces c-Myc degradation by directly targeting ERK2 in lung cancer in vitro and in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2601. doi:10.1158/1538-7445.AM2015-2601