Enhanced targeting of triple-negative breast carcinoma and malignant melanoma by photochemical internalization of CSPG4-targeting immunotoxins

Triple-negative breast cancer (TNBC) and malignant melanoma are highly aggressive cancers that widely express the cell surface chondroitin sulfate proteoglycan 4 (CSPG4/NG2). CSPG4 plays an important role in tumor cell growth and survival and promotes chemo- and radiotherapy resistance, suggesting that CSPG4 is an attractive target in cancer therapy. In the present work, we applied the drug delivery technology photochemical internalization (PCI) in combination with the novel CSPG4-targeting immunotoxin 225.28-saporin as an efficient and specific strategy to kill aggressive TNBC and amelanotic melanoma cells. Light-activation of the clinically relevant photosensitizer TPCS2a (fimaporfin) and 225.28-saporin was found to act in a synergistic manner, and was superior to both PCI of saporin and PCI-no-drug (TPCS2a + light only) in three TNBC cell lines (MDA-MB-231, MDA-MB-435 and SUM149) and two BRAFV600E mutated malignant melanoma cell lines (Melmet 1 and Melmet 5). The cytotoxic effect was highly dependent on the light dose and expression of CSPG4 since no enhanced cytotoxicity of PCI of 225.28-saporin compared to PCI of saporin was observed in the CSPG4-negative MCF-7 cells. The PCI of a smaller, and clinically relevant CSPG4-targeting toxin (scFvMEL-rGel) validated the CSPG4-targeting concept in vitro and induced a strong inhibition of tumor growth in the amelanotic melanoma xenograft A-375 model. In conclusion, the combination of the drug delivery technology PCI and CSPG4-targeting immunotoxins is an efficient, specific and light-controlled strategy for the elimination of aggressive cells of TNBC and malignant melanoma origin. This study lays the foundation for further preclinical evaluation of PCI in combination with CSPG4-targeting.

Abstract P1-01-23: Hypoxia induced centrosome amplification via HIF-1α/Plk4 signaling axis associates with poorer overall survival in TNBC

Background: Centrosome amplification (CA) which refers to presence of supernumerary or abnormally large centrosomes drives tumor progression by promoting chromosomal instability and the generation of aggressive tumor clones. Although the role of CA in cancer progression is well-defined, no studies have yet discussed how CA is induced in tumor cells. We report here that intra-tumoral hypoxia, which is considered one of the major contributors to intratumor heterogeneity, induces CA via HIF-1α.

Methods: We first immunohistochemically labeled 24 breast carcinoma and uninvolved adjacent normal tissue samples for HIF-1α and calculated weighted indices (WIs) for nuclear HIF-1α. Adjacent serial sections from the same tumors were also immunofluorescently labeled for γ-tubulin and CA was calculated. Using public microarray datasets (Kao dataset, n=327), we investigated whether centrosomal gene expression is enriched in breast tumors characterized by a hypoxia gene expression signature. Finally, to determine the role of hypoxia in CA induction we exposed cultured TNBC cells (MDA-MB-231 and MDA-MB-468) to hypoxia and overexpressed (OE) and knocked out (KO) HIF-1α in TNBC cells and quantitated CA. Additionally, to discern the biological pathway through which HIF-1α induces CA we performed ChIP assay and in silico analyses to identify the possible targets of HIF-1α.

Results: A strong positive correlation between nuclear HIF-1α WI and CA was found in breast tumor samples (Spearman's rho p=0.722, p<0.001). In addition, we found that higher nuclear HIF-1α was associated with worse overall survival (p=0.041; HR=1.03). Our in silico findings suggest that breast tumors with high expression of hypoxia-associated genes exhibited higher expression of centrosomal genes than breast tumors with low expression of hypoxia-associated genes. In addition, cells cultured in hypoxic conditions exhibited ˜1.5 fold higher (p<0.05) CA when compared to the cells cultured in normoxic conditions. Interestingly level of CA decreased when HIF-1α KO TNBC cells were exposed to hypoxia and it increased when HIF-1α OE TNBC cells were culture in normoxic conditions. Furthermore, we discovered that HIF-1α induced CA by directly regulating the expression of Plk4 which was confirmed by performing ChIP assay. Our results indicated HIF-1α interaction with the motif in the PLK4 promoter from genomic DNA of MDA-MB 231 cells under hypoxic conditions, was significantly (p=0.04) higher when compared with the cells cultured under normoxic conditions. Plk4 mRNA expression was assessed using the online BC gene expression data sets (n=25). We found significantly higher expression of Plk4 in TNBC (n=374) when compared with non-TNBC (n=4098) and it was associated with poor overall survival (HR=1.76; p=0.054) in TNBC.

Conclusion: Collectively our findings suggest that hypoxia drives CA in TNBC via HIF-1α and contribute to poor outcomes. Thus, determination of CA and HIF-1α can help risk stratification in TNBC patients for more personalized treatments.

Citation Format: Mittal K, Choi DH, Maganti N, Ogden A, Melton BD, Kaur J, Gupta MV, Jonsdottir K, Janseen EAM, Aleskandarany MA, Rakha EA, Rida PCG, Aneja R. Hypoxia induced centrosome amplification via HIF-1α/Plk4 signaling axis associates with poorer overall survival in TNBC [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 P1-01-23.

Salivary biomarkers for oral cancer and pre-cancer screening: a review

OBJECTIVE

The objective of the study was to conduct a systematic review of the literature assessing potential salivary biomarkers of oral cancer and pre-cancer and discuss emerging issues and challenges in relation to oral cancer and pre-cancer diagnostics.

MATERIALS AND METHODS

Search for articles involved the Medline, PubMed, and EMBASE. Specific terms were used from January 1995 to March 2017 by three experts.

RESULTS

This search collected 270 articles, of which 105 articles such as reviews, case reports, news, letter to editor, etc. in first round and 117 articles such as publications in other languages than English, non-human studies, etc. were excluded. The remaining 48 articles considered analyzing whole saliva as well as specific gland saliva. Thirty-one studies considered oral stimuli such as eating, drinking, and oral hygiene practices for varied periods of time prior to sample collection. The time of collection of saliva was morning in most studies, but the exact time of collection was not mentioned. Three studies showed to have evaluated the whole saliva without centrifugation. Two-dimensional gel electrophoresis and tandem mass spectrometry were the most commonly used methods. Most of the potential salivary biomarkers of oral cancer are salivary proteins.

CONCLUSION

Combination approach of salivary biomarkers could be used as screening tool to improve early detection and diagnostic precision of oral pre-cancer and cancer.

CLINICAL RELEVANCE

The current findings are of importance for clinicians and researchers to mitigate the challenges in salivary-based diagnosis of oral cancer and to evaluate reliable, specific, and sensitive salivary biomarkers for oral pre-cancer and cancer diagnosis.

Effect of maternal oxygen inhalation on foetal free radical activity: a prospective, randomized trial

BACKGROUND

Maternal inhalation of 35-40% oxygen concentration has no significant effect on foetal partial pressure of oxygen, and 60-100% produced maternal and foetal hyperoxia with increased free radical activity. The benefit of 50% maternal oxygen inhalation on foetal oxygenation, oxidant stress and total antioxidant status (TAS) during Caesarean section (CS) has not been simultaneously evaluated.

METHODS

In this prospective, randomized, controlled trial 120 ASA physical status I-II, term pregnant women were recruited to elective CS (n = 60) and emergency CS (n = 60) and received either 50% oxygen or air inhalation following subarachnoid block (SAB). Patients and investigators were blinded to the inhaled oxygen concentration. The primary outcome of the study was foetal umbilical artery (UA) malondialdehyde (MDA) at birth.

RESULTS

In both elective and emergency CS, there was no difference in foetal oxidative stress and TAS in spite of increase in maternal PaO2. In elective CS, maternal MDA was higher at delivery in mothers breathing 50% oxygen as compared to their own baseline values (P = 0.04). In emergency CS, maternal TAS at 10 min was lower in mothers inhaling 50% oxygen as compared to air (P = 0.01). The average duration of maternal oxygen supplementation was ~10.3 min in elective and ~7.4 min in emergency CS. Neonatal outcome, episodes of maternal hypotension and oxygen desaturation were similar in both the groups.

CONCLUSION

Brief duration of 50% oxygen maternal inhalation during elective or emergency CS did not significantly affect foetal MDA and TAS under SAB.

Examples of dynamic chirality in nuclei

In many cases the chirality was almost observed but the transition probabilities are different. This fact is clearly seen in the cases of 134Pr and 102Rh. In the case of chirality, the yrast and the side bands should be nearly degenerate. In the angular momentum region where chirality sets, the B(E2) values of the electromagnetic transitions deexciting analog states of the chiral twin bands should be almost equal. Correspondingly the B(M1) values should exhibit staggering. Our lifetime measurements in the cases of 134Pr and 102Rh and the theoretical analysis do not support static chirality. Chirality has mainly a dynamical character in both nuclei. In the present paper, we compare our results with the results for other chiral candidate nuclei, which fulfill static chirality conditions.

Aberrant promoter hypermethylation of selected apoptotic genes in childhood acute lymphoblastic leukemia among North Indian population

Promoter hypermethylation mediates gene silencing in many neoplasms. Acute leukemia has been reported to harbor multiple genes aberrantly silenced by hypermethylation.

AIM

In present study, we investigated the prevalence of hypermethylation of caspase-8 (CASP8), TMS1 and DAPK genes in correlation with clinicopathological factors in childhood acute lymphoblastic leukemia (ALL).

MATERIALS AND METHODS

A case-control study has been conducted based on bone marrow and peripheral blood samples from 125 ALL patients and 100 sex-age matched healthy controls. Methylation specific polymerase chain reaction (PCR) and bisulfite sequencing PCR was performed to analyze the methylation status of these genes. Reverse transcription PCR and real time PCR was carried out to determine changes in the mRNA expression level of the genes due to hypermethylation.

RESULTS

Hypermethylation of the 5´CpG islands of the CASP8, TMS1 and DAPK gene promoters was found in 3.2, 6.4, and 13.6% of 125 childhood ALL samples from north Indian population, respectively. There were significant differences in pattern of hypermethylation of TMS1 (p = 0.045) and DAPK (p < 0.001) between patients and healthy controls. Down-regulation of mRNA expression was found in cases in which CASP8, TMS1 and DAPK were hypermethylated.

CONCLUSIONS

The present study indicated the impact of hypermethylation-mediated inactivation of CASP8, TMS1 and DAPK genes, which is associated with risk of childhood ALL. This abnormality occurs in leukemogenesis and it may be used as a biomarker and for predicting the prognosis of ALL.

Suicide and self-inflicted injury hospitalizations in Canada (1979 to 2014/15)

INTRODUCTION

The purpose of this paper is to describe the trends and patterns of self-inflicted injuries, available from Canadian administrative data between 1979 and 2014/15, in order to inform and improve suicide prevention efforts.

METHODS

Suicide mortality and hospital separation data were retrieved from the Public Health Agency of Canada (PHAC) holdings of Statistics Canada's Canadian Vital Statistics: Death Database (CVS:D) (1979 to 2012); Canadian Socio-Economic Information Management System (CANSIM 2011, 2012); the Hospital Morbidity Database (HMDB) (1994/95 to 2010/11); and the Discharge Abstract Database (2011/12 to 2014/15). Mortality and hospitalization counts and rates were reported by sex, 5-year age groups and method.

RESULTS

The Canadian suicide rate (males and females combined, all ages, age-sex standardized rate) has decreased from 14.4/100 000 (n = 3355) in 1979 to 10.4/100 000 (n = 3926) in 2012, with an annual percent change (APC) of -1.2% (95% CI: -1.3 to -1.0). However, this trend was not observed in both sexes: female suicide rates stabilized around 1990, while male rates continued declining over time-yet males still accounted for 75.7% of all suicides in 2012. Suffocation (hanging and strangulation) was the primary method of suicide (46.9%) among Canadians of all ages in 2012, followed by poisoning at 23.3%. In the 2014/15 fiscal year, there were 13 438 hospitalizations in Canada (excluding Quebec) associated with self-inflicted injuries-over 3 times the number of suicides. Over time females have displayed consistently higher rates of hospitalization for self-inflicted injury than males, with 63% of the total. Poisoning was reported as the most frequent means of self-inflicted harm in the fiscal year 2014/15, at 86% of all hospitalizations.

CONCLUSION

Suicides and self-inflicted injuries continue to be a serious - but preventable - public health problem that requires ongoing surveillance.

Microbial pectinases: an ecofriendly tool of nature for industries

Pectinases are the growing enzymes of biotechnological sector, showing gradual increase in their market. They hold a leading position among the commercially produced industrial enzymes. These enzymes are ecofriendly tool of nature that are being used extensively in various industries like wine industry; food industry; paper industry for bleaching of pulp and waste paper recycling; in the processing of fruit–vegetables, tea–coffee, animal feed; extraction of vegetable oil and scouring of plant fibres. Moreover, enzymatic catalysis is preferred over other chemical methods, since it is more specific, less aggressive and saves energy. This is the review which covers the information available on the applicability potential of this group of enzymes in various sectors.

Concerns about usage of smartphones in operating room and critical care scenario

Smartphones and tablets have taken a central place in the lives of health care professionals. Their use has dramatically improved the communication and has become an important learning tool as the medical information can be assessed online at anytime. In critical care settings, use of smartphone facilitates quick passage of information through E-mail messaging and getting feedback from the concerned physician quickly, thereby reducing medical errors. However, in addition to the benefits offered, these devices have become a significant source of nosocomial infections, distraction for medical professionals and interfere with medical equipments. They may also put privacy and security of patients at stake. The benefits could be severely undermined if abuse and over use are not kept in check. This review article focuses on various applications of smartphones in healthcare practices, drawback of the use of these devices and the recommendations regarding the safe use of these devices.

A COMPARATIVE ANALYSIS OF METHYLATION STATUS OF TUMOR SUPPRESSOR GENES IN PAIRED BIOPSY AND SERUM SAMPLES FROM CERVICAL CANCER PATIENTS AMONG NORTH INDIAN POPULATION

Tumor-specific genetic or epigenetic alterations have been detected in serum DNA in case of various types of cancers. In breast cancer, the detection of tumor suppressor gene hypermethylation has been reported in several body fluids. Promoter hypermethylation of some genes like MYOD1, CALCA, hTERT etc. has also been detected in serum samples from cervical cancer. The present study is the first report on the comparison of promoter hypermethylation of tumor suppressor genes likep14, p15, p16, p21, p27, p57, p53, p73, RARβ2, FHIT, DAPK, STAT1 and-RB1 genes in paired biopsy and serum samples from cervical cancer patients among north Indian population. This is also the first report on the hypermethylation of these genes in serum samples from cervical cancer patients among north Indian population. According to the results of the present study, promoter hypermethylation of these genes can also be detected in serum samples of cervical cancer patients. The sensitivity of detection of promoter hypermethylation in serum samples of cervical cancer patients as compared to paired biopsy samples was found to be around 83.3%. It was observed that promoter hypermethylation was mainly observed in the serum samples in the higher stages and very rarely in the lower stages. The present study clearly showed that serum of patients with cervical cancer can also be used to study methylated genes as biomarkers.