Comprehensive molecular exploration identified promoter DNA methylation of the CRBP1 gene as a determinant of radiation sensitivity in rectal cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (NCRT) for advanced rectal cancer (RC) is a well-evidenced therapy; however, some RC patients have no therapeutic response. Patient selection for NCRT so that non-responsive patients are excluded has been subjective. To date, no molecular markers indicating radiation sensitivity have been reported.

METHODS

We irradiated six colorectal cancer (CRC) cell lines and identified HCT116 cells as radiation-sensitive and HCT15 and DLD-1 cells as radiation resistant. Using a microarray, we selected candidate radiation sensitivity marker genes by choosing genes whose expression was consistent with a radiation-resistant or sensitive cell phenotype.

RESULTS

Among candidate genes, cellular retinol binding protein 1 (CRBP1) was of particular interest because it was not only induced in HCT116 cells by tentative 10 Gy radiation treatments, but also its expression was increased in HCT116-derived radiation-resistant cells vs parental cells. Forced expression of CRBP1 decreased the viability of both HCT15 and DLD-1 cells in response to radiation therapy. We also confirmed that CRBP1 was epigenetically silenced by hypermethylation of its promoter DNA, and that the quantitative methylation value of CRBP1 significantly correlated with histological response in RC patients with NCRT (P=0.031).

CONCLUSIONS

Our study identified CRBP1 as a radiation-sensitive predictor in RC.

The clinical significance of cysteine dioxygenase type 1 methylation in Barrett esophagus adenocarcinoma

Methylation of cysteine dioxygenase type 1 (CDO1) gene, a tumor suppressor gene, has been studied in various cancers; however, there is no information regarding Barrett esophagus cancer. In this study, the clinical significance of CDO1 methylation in Barrett esophagus adenocarcinoma (BEA) was clarified. CDO1 gene promoter methylation was analyzed for DNA from the patient's specimens using quantitative methylation-specific polymerase chain reaction. Thirty-eight BEA patients who underwent resection were identified between 2000 and 2014. Hypermethylation of CDO1 gene was demonstrated to be frequently recognized even at early stage in BEA by quantitative methylation-specific polymerase chain reaction. In BEA, there is a robust prognostic difference between stage I and stage II/III/IV with regard to 5-year relapse-free survival (P = 0.0016) and 5-year overall survival (P = 0.0024), and the tumor size separated by 7 cm was also a prognostic factor. There was significant difference in CDO1 gene methylation according to the tumor size (P = 0.036). BEA patients with CDO1 gene methylation were shown marginally significantly poorer prognosis (P = 0.054) than otherwise patients. In conclusion, higher CDO1 gene methylation was seen in BEA at earlier stage than in squamous cell carcinoma, and it may account for aggressive phenotype of BEA.

The question of whether or not to perform therapeutic hypothermia: A case of neonatal spinal cord injury

Neonatal spinal cord injury is an extremely rare perinatal complication that often occurs concurrently with hypoxic ischemic encephalopathy (HIE), further complicating diagnosis of spinal cord injury. Although therapeutic hypothermia for moderate to severe HIE is widely recommended in Japan, it is difficult to determine whether it satisfies the neurological findings-related entry criteria in some patients.We describe a female infant with neonatal spinal cord injury after forceps delivery, who underwent therapeutic hypothermia upon diagnosis of HIE. The Apgar scores were 5 at 1 min, 6 at 5 min, and not recorded at 10 min. Blood gas analysis of her umbilical artery was not performed. Since respiratory failure, hypotonia and the absence of primitive reflexes were found at 2 hours after birth, she was initially diagnosed with moderate HIE and underwent a therapeutic hypothermia. Magnetic resonance imaging after therapeutic hypothermia revealed the spinal cord was narrowed from the lower medulla oblongata to the upper cervical cord. Thus she was diagnosed with an upper spinal cord injury at that time.Some patients with neonatal spinal cord injuries satisfy the criteria for therapeutic hypothermia. When neonates with asphyxia present with prolonged respiratory failure and hypotonia, spinal cord injury should be considered in the differential diagnosis. Thus, an early MRI is vital for the diagnosis of spinal cord injury.

Robots in Human Environments: Basic Autonomous Capabilities

This article discusses the basic capabilities needed to enable robots to operate in human-populated environments for accomplishing both autonomous tasks and human-guided tasks. These capabilities are key to many new emerging robotic applications in service, construction, field, underwater, and space. An important characteristic of these robots is the “assistance” ability they can bring to humans in performing various physical tasks. To interact with humans and operate in their environments, these robots must be provided with the functionality of mobility and manipulation. The article presents developments of models, strategies, and algorithms concerned with a number of autonomous capabilities that are essential for robot operations in human environments. These capabilities include: integrated mobility and manipulation, cooperative skills between multiple robots, interaction ability with humans, and efficient techniques for real-time modification of collision-free path. These capabilities are demonstrated on two holonomic mobile platforms designed and built at Stanford University in collaboration with Oak Ridge National Laboratories and Nomadic Technologies.

Congenital rubella syndrome with death from interstitial pneumonia

There was a rubella epidemic in Japan in 2012-2013, which led to an increased number infants being born with congenital rubella syndrome (CRS). Symptoms of CRS are varied and include cataracts, congenital heart disease, and hearing impairment, but case reports of CRS complicated by interstitial pneumonia are rare. We report the case of a patient with CRS who died of respiratory failure caused by interstitial pneumonia. Thrombocytopenia had been present for approximately 1 month after birth, and the patient presented with sudden lung hemorrhage at 64 days old. Thereafter, respiratory condition deteriorated, and the patient died at 107 days old. Given that infants with CRS who have thrombocytopenia and interstitial pneumonia have a high risk of death, they should be monitored carefully for potential complications.

Abstract P3-06-07: Changes in the tumor microenvironment develop acquired resistance to pegylated liposomal doxorubicin in breast cancer mouse model

Pegylated liposomal doxorubicin (PLD) is one of the most widely used nanotherapeutics for the treatment of advanced/metastatic breast cancer. PLD accumulates in tumors utilizing so-called the enhanced permeation and retention (EPR) effect. Nevertheless, therapeutic efficacy and long term survival remain variable due to the development of acquired resistance. Elucidating the mechanisms of acquired resistance to PLD shall help developing new strategies to improve therapeutic outcome. It has been largely overlooked that the transport of therapeutics across biological barriers can significantly affect the efficacy of cancer therapies. Previously, we showed that the transport of PLD to tumors depends both on the tumor type and organ site. This effect is controlled by the extent to which endothelial cells (ECs) are covered by the collagen type IV (Col4) in the basement membrane, which in turn is influenced by the levels of MMP-9. Here, we have developed 4T1 tumor model which develops acquired resistance to PLD and spontaneous lung metastases. Our objective is to elucidate the resistant mechanism by evaluating the changes in the transport of PLD to the sensitive and resistant/metastatic tumors.

BALB/c mice bearing 4T1 cancers were treated with PLD intravenously when tumor volumes reached a size of approximately 100-200 mm3 . Tumor volumes in all mice decreased after initial PLD injections (sensitive). However, tumors started to grow again after 20 days and didn't respond to the second/third injections (resistant). Furthermore, 13 out of 14 mice developed spontaneous lung metastases. To elucidate the mechanisms of the resistance, mice bearing sensitive or resistant tumors were sacrificed after 24 hours of PLD injection, respectively. PLD accumulation in tumors was evaluated by imaging fluorescence of doxorubicin. Immunofluorescence staining was performed to evaluate the expression of ECs, Col4, MMP-9, and efflux pump associated p-glycoprotein (P-gp) in the primary tumors, and the expression of ECs and Col4 were also evaluated in lung metastases.

PLD accumulation was significantly decreased in the resistant tumors compared to the sensitive tumors, although P-gp expression was not increased in the resistant tumors. The amount of ECs and Col4 increased in the resistant tumors. Interestingly, ECs were covered more tightly by Col4 in the resistant tumors as compared with the sensitive tumors, which could decrease the EPR effect in the tumors. MMP-9 expression decreased in the resistant tumors, suggesting less degradation of Col4 in the basement membrane. Coverage of ECs by Col4 was similar between the metastatic lung tumors and uninvolved lung tissue as well as the resistant primary tumors, indicating the EPR effect is not increased in the metastatic tumors.

In summary, ratio of ECs covered by Col4 is higher in the resistant/metastatic tumors as compared to that in the sensitive primary tumors. This structural change in the tumor microenvironment, impeding the sufficient PLD transport to the tumors after the initial PLD therapy, can be a cause of acquired resistance/development of lung metastasis. These changes should be taken into account to develop strategies for overcoming the acquired resistance and metastasis.

Citation Format: Kai M, Liu YT, Saito Y, Ferrari M, Yokoi K. Changes in the tumor microenvironment develop acquired resistance to pegylated liposomal doxorubicin in breast cancer mouse model. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-06-07.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for the Revision of the Clinical and Pathologic Staging of Small Cell Lung Cancer in the Forthcoming Eighth Edition of the TNM Classification for Lung Cancer

INTRODUCTION

Small cell lung cancer (SCLC) is commonly classified as either limited or extensive, but the Union for International Cancer Control TNM Classification of Malignant Tumours seventh edition (2009) recommended tumor, node, and metastasis (TNM) staging based on analysis of the International Association for the Study of Lung Cancer (IASLC) database.

METHODS

Survival analyses were performed for clinically and pathologically staged patients presenting with SCLC from 1999 through 2010. Prognosis was compared in relation to the TNM seventh edition staging to serve as validation and analyzed in relation to proposed changes to the T descriptors found in the eighth edition.

RESULTS

There were 5002 patients: 4848 patients with clinical and 582 with pathological stages. Among these, 428 had both. Survival differences were confirmed for T and N categories and maintained in relation to proposed revisions to T descriptors for seventh edition TNM categories and proposed changes in the eighth edition. There were also survival differences, notably at 12 months, in patients with brain-only single-site metastasis (SSM) compared to SSM at other sites, and SSM without a pleural effusion showed a better prognosis than other patients in the M1b category.

CONCLUSION

We confirm the prognostic value of clinical and pathological TNM staging in patients with SCLC, and recommend continued usage for SCLC in relation to proposed changes to T, N, and M descriptors for NSCLC in the eighth edition. However, for M descriptors, it remains uncertain whether survival differences in patients with SSM in the brain simply reflect better treatment options rather than better survival based on anatomic extent of disease.

Abstract P6-04-21: Novel therapy of liver metastases of cancer using abraxane loaded into multi-stage nanovector

Purpose; To investigate whether the Abraxane loaded within Multi-Stage Nanovector (MSV) system (MSV-ABX) is more effective in therapy of liver metastases of breast and lung cancer as compared to Abraxane (ABX).

Experimental Design; MTT assay was performed to evaluate sensitivity of 4T1, murine breast cancer cells and 3LL, murine lung cancer cells to ABX or MSV-ABX in vitro. Experimental liver metastases were produced by intra-splenic injection of 4T1 or 3LL cells in Balb/C mice. The mice bearing liver metastases were treated with intravenous injection of (1) control (PBS), (2) ABX or (3) MSV-ABX. Then the mice were sacrificed and liver weight was measured to evaluate the therapeutic efficacy. To evaluate the biological the effects of therapeutics, we performed histological and immunohistochemical analysis of the tumor specimens. Apoptosis of 4T1 and 3LL tumor cells were evaluated by TUNEL staining, and proliferation of the tumor cells were stained using antibody to Ki67. Tumor diameter was measured in H&E stained sections.

Results; There was no significant difference in the sensitivity of 4T1 and 3LL cancer cells to ABX and MSV-ABX, in vitro. All the mice injected with 4T1 or C3LL cells developed multiple liver metastases. The liver weight was significantly lower in the mice treated with MSV-ABX as compared to those in the other groups. The tumor diameters in the liver were significantly smaller in the mice treated with MSV-ABX as compared to those in the other two groups. Immunofluorescent analysis revealed that MSV-ABX inhibited proliferation and increased apoptosis of 4T1 and 3LL tumor cells in the liver significantly more than ABX.Conclusions; These studies demonstrate that MSV-ABX is more effective than ABX in therapy of the liver metastasis of breast and colorectal cancer in our mouse models. These data can be translated into the clinic for planning novel clinical trials using MSV-ABX.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-04-21.

Abstract P4-06-13: Discovering serum biomarkers for predicting accumulation of nanotherapeutics to different tumor and organ microenvironments

Surrogate biomarkers in the circulation for the enhanced permeation and retention (EPR) effect in different tumor and organ microenvironment shall aid in selecting patients who are likely to accumulate higher amount of nanotherapeutics to tumors and thus show better response to the therapeutics. In this study, 4T1 and 3LL murine cancer cell lines, known to have similar sensitivity to pegylated liposomal doxorubicin (PLD) in vitro, were shown to accumulate significantly different quantities of PLD in vivo. PLD accumulation correlated with tumor-specific differences in therapeutic efficacy and vascular permeability, which was modulated by the extent of coverage of tumor-associated endothelial cells by basement membrane. Matrix metalloproteinase (MMP)-9 and its endogenous inhibitor, tissue inhibitor of metalloproteinase (TIMP)-1, played a pivotal role in these phenomena. Differences in vascular permeability and PLD accumulation were also organ-specific and significantly correlated with the relative ratio of MMP-9 and TIMP-1 in the systemic circulation of the tumor-bearing mice. Our findings support the further development of MMP-9 and TIMP-1 as paired serum biomarkers for predicting accumulation of PLD to tumor and the application of these biomarkers could be expanded to other types of nanotherapeutics utilizing the EPR effect for the personalization of cancer therapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-06-13.

Time to first cigarette and lung cancer risk in Japan

BACKGROUND

Cigarette smoking is the major cause of lung cancer (LC). Although the time to first cigarette (TTFC) of the day is a distinct indicator of nicotine dependence, little information is available on its possible relation to LC.

PATIENTS AND METHODS

This case-control study includes a total of 1572 incident LC cases and 1572 non-cancer controls visiting for the first time the Aichi Cancer Center Hospital between 2001 and 2005. We estimated the odds ratio (OR) and 95% confidence interval (CI) for TTFC using a logistic regression model after adjustment for several potential confounders.

RESULTS

TTFC was inversely associated with the risk of LC. This association was consistent across histological subtypes of LC. For all LCs considered among ever smokers and after accurate allowance for smoking quantity and duration, besides other relevant covariates, compared with TTFC >60 min, the adjusted ORs were 1.08 (95% CI, 0.73-1.61) for TTFC of 31-60 min, 1.40 (0.98-2.01) for 6-30 min and 1.86 (1.28-2.71) for within 5 min (Ptrend, < 0.001). Statistically marginally significant heterogeneity by histological subtype was observed (Pheterogeneity, 0.002).

CONCLUSIONS

Nicotine dependence, as indicated by the TTFC, is associated with increased risk of LC and is therefore an independent marker of exposure to tobacco smoking.