Heterogeneous (gas-solid) chemistry of atmospheric Cr: A case study of Astana, Kazakhstan

Hexavalent chromium (Cr(VI)) is a known carcinogen derived from both anthropogenic and natural sources. This work reports the size-segregated concentrations of total Cr(VI) in particulate matter (PM) in Astana, the capital of Kazakhstan, and provides new insights into the gas-solid reactions of atmospheric Cr. A study of total Cr(VI) in the particulate matter, via a microwave-assisted digestion technique, was conducted using a 5-stage Sioutas Cascade impactor that captures airborne particles in size ranges: >2.5 μm, 1.0-2.5 μm, 0.50-1.0 μm, 0.25-0.50 μm, and <0.25 μm. The total Cr(VI) concentration in the size fraction <0.25 μm was the highest with a maximum value of 9.7 ng/m3. This high concentration may pose a greater risk because smaller airborne particles can penetrate deeper into the lower respiratory tract of the lungs. Total suspended particles Cr(VI) exceeded the 8.0 ng/m3 Reference Concentration (RfC) by 22 times. The overall total Cr(VI) concentration in summer was significantly higher than in fall (p < 0.05), which could be due to factors, including higher temperatures, ozone, and NO2 concentrations in summer and a higher VOC concentration in fall. The results indicate that the interaction between Cr(III) and Cr(VI) through gas-solid reaction can control the speciation of atmospheric Cr.

Quantification and the sources identification of total and insoluble hexavalent chromium in ambient PM: A case study of Aktobe, Kazakhstan

Hexavalent chromium (Cr(VI)), a known carcinogen, emanates from both anthropogenic and natural sources. A pilot study of the ambient Cr(VI) concentrations was conducted at the center of Aktobe which is a few kilometers away from major industrial chromium plants. Total Cr(VI) concentrations were measured in the fall and winter seasons with mean values (S.D) of 5.30 (2.16) ng/m³ and 2.26 (1.80) ng/m³, respectively. Insoluble Cr(VI) levels were 4.80 (1.96) and 2.19 (1.75) ng/m³ for the fall and winter, respectively. The total and insoluble Cr(VI) concentrations in the fall season were significantly higher than in winter, likely due to the higher rate of Cr(III) oxidation in the presence of ozone and ROS in fall compared to the rate of Cr(VI) reduction in the presence of VOCs at higher temperatures. On average, total Cr(VI) constituted 34.49% of the total Cr concentrations suggesting that the dominant valence state of Cr in the atmosphere is Cr(III). The previous reference values of exposure to Cr(VI) must be revisited by taking into account the insoluble Cr(VI) concentration since it is more prevalent in the atmosphere compared to soluble Cr(VI). The influence of the chromium plants as potential sources was not obvious in this study.

Spatial interaction between breast cancer and environmental pollution in the Monterrey Metropolitan Area

This research examines the spatial structure of a sample of breast cancer (BC) cases and their spatial interaction with contaminated areas in the Monterrey Metropolitan Area (MMA). By applying spatial statistical techniques that treat the space as a continuum, degrees of spatial concentration were determined for the different study groups, highlighting their concentration pattern. The results indicate that 65 percent of the BC sample had exposure to more than 56 points of PM10. Likewise, spatial clusters of BC cases of up to 39 cases were identified within a radius of 3.5 km, interacting spatially with environmental contamination sources, particularly with refineries, food processing plants, cement, and metals. This study can serve as a platform for other clinical research by identifying geographic clusters that can help focus health policy efforts.

Residential proximity to industrial pollution sources and colorectal cancer risk: A multicase-control study (MCC-Spain)

BACKGROUND

Colorectal cancer is the third most frequent tumor in males and the second in females worldwide. In Spain, it is an important and growing health problem, and epidemiologic research focused on potential risk factors, such as environmental exposures, is necessary.

OBJECTIVES

To analyze the association between colorectal cancer risk and residential proximity to industries, according to pollution discharge route, industrial groups, categories of carcinogens and other toxic substances, and specific pollutants released, in the context of a population-based multicase-control study of incident cancer carried out in Spain (MCC-Spain).

METHODS

MCC-Spain included 557 colorectal cancer cases and 2948 controls in 11 provinces, frequency matched by sex, age, and region of residence. Distances were computed from subjects' residences to each of the 134 industries located in the study area. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance (from 1 km to 3 km) to industrial facilities, adjusting for matching variables and other confounders.

RESULTS

Excess risk (OR; 95%CI) of colorectal cancer was detected near industries overall for all distances analyzed, from 1 km (2.03; 1.44-2.87) to 3 km (1.26; 1.00-1.59). In general, industries releasing pollutants to air showed higher excess risks than facilities releasing pollution to water. By industrial sector, excess risk (OR; 95%CI) was found near (≤3 km) production of metals (2.66; 1.77-4.00), surface treatment of metals (1.48; 1.08-2.02), glass and mineral fibers (2.06; 1.39-3.07), organic chemical industry (4.80; 3.20-7.20), inorganic chemical industry (6.74; 4.38-10.36), food/beverage sector (3.34; 2.38-4.68), and surface treatment using organic solvents (6.16; 4.06-9.36). By pollutants, the main excess risks (OR; 95%CI) were found near (≤3 km) industries releasing nonylphenol (9.19; 5.91-14.28), antimony (5.30; 3.45-8.15), naphthalene (3.11; 2.16-4.49), organotin compounds (2.64; 1.76-3.98), manganese (2.53; 1.63-3.93), dichloromethane (2.52; 1.74-3.66), and vanadium (2.49; 1.59-3.91).

CONCLUSIONS

Our results support the hypothesis that residing in the proximity of industries may be a risk factor for colorectal cancer.

Spatio-temporal analysis of colorectal cancer using a geographic information system in the Iranian military community during the period 2007-2016

INTRODUCTION

Colorectal cancer (CRC) is one of the most prevalent cancers among Iranian people. The study of spatio-temporal distribution of disease has an important role in the design of disease prevention programmes. The purpose of the current study was to describe the spatio-temporal distribution of CRC in the Iranian military community as a sample of the Iranian population.

METHODS

In the current ecological study, all registered cancer cases in the Iranian military community during the period 2007-2016 were considered. To identify hotspots, Getis-Ord Gi statistics were used. All analyses were performed using ArcGIS 10.5 and Excel 2010.

RESULTS

The highest incidences of CRC in 2007-2008, 2009-2010 and 2011-2012 were recorded in Kermanshah province. The highest incidences of CRC in 2013-2014 were seen in Kermanshah, Ghilan, Tehran and North Khorasan. In 2007-2008 and 2009-2010, hotspots were detected in West Azarbayjan. In 2011-2012, hotspots were detected in Zanjan and Qazvin. In 2013-2014, a hotspot was detected in Qazvin. Finally, West Azerbaijan was the hotspot for CRC in 2015-2016.

CONCLUSIONS

The incidence of CRC in men was higher than in women. Also it appeared that North and North West Iran were risk areas for this disease, and so these areas should be considered in the design of disease prevention programme for this cancer type. Additionally, the determination of individual risk factors in the aforementioned geographical areas can play an important role in the prevention of this type of cancer.

microRNA‑577 inhibits cell proliferation and invasion in non‑small cell lung cancer by directly targeting homeobox A1

An increasing number of studies have indicated that the dysregulation of microRNAs (miRNAs/miR) is closely associated with non‑small cell lung cancer (NSCLC) development and progression by acting as tumor suppressors or oncogenes. Therefore, an in‑depth understanding of the biological roles of miRNAs in NSCLC may provide novel therapeutic methods for the treatment of patients with this disease. In the present study, reverse transcription‑quantitative polymerase chain reaction was used to detect miR‑577 expression in NSCLC tissues and cell lines. Cell Counting Kit‑8 and Transwell invasion assays were performed to determine the effects of miR‑577 on NSCLC cell proliferation and invasion. Luciferase reporter assays were used to demonstrate the relationship between miR‑577 and homeobox A1 (HOXA1) in NSCLC cells. The results revealed that miR‑577 was markedly downregulated in NSCLC tissues and cell lines. Additionally, restoration of miR‑577 expression significantly decreased the proliferation and invasion of NSCLC cells. Furthermore, miR‑577 negatively regulated HOXA1 expression in NSCLC cells by directly binding to its 3'‑untranslated region. HOXA1 was significantly upregulated in NSCLC tissues, and its upregulation was inversely correlated with miR‑577. Notably, restored HOXA1 expression abrogated the reduced proliferation and invasion of NSCLC cells caused by miR‑577 overexpression. Taken together, these results indicated that miR‑577 may have served tumor suppressive roles in NSCLC by directly targeting HOXA1. Therefore, this miRNA may be developed as a potential therapeutic target for the therapy of patients with NSCLC.

MicroRNA-1246 inhibits cell invasion and epithelial mesenchymal transition process by targeting CXCR4 in lung cancer cells

BACKGROUND

Recent studies have indicated that microRNAs (miRNAs) are closely related to lung cancer. However, the effects of miR-1246 on lung cancer are still elusive. In this study, we aimed to explore the molecular mechanisms of miR-1246 in lung cancer.

MATERIALS AND METHODS

Using RT-qPCR assay, we analyzed the expression of miR-1246 in lung cancer cell lines and lung epithelial cell line. Using Cell Counting Kit-8 (CCK-8), flow cytometry, Transwell, RT-qPCR and western blot assays, we investigated cell viability, apoptosis, invasion and epithelial mesenchymal transition (EMT) process. Using luciferase reporter assay, we confirmed a target of miR-1246. Using western blot assay, we detected the protein mechanisms of Janus kinase (JAK)/signal transducer and activator of transcription (STAT) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) signal pathways.

RESULTS

Our results showed that miR-1246 was down-regulated in lung cancer cell lines (A549, H1650 and H1299) compared to in lung epithelial cell line (16HBE14o). MiR-1246 overexpression remarkably inhibited cell invasion as well as up-regulated E-cadherin expression and down-regulated N-cadherin, Vimentin, ZEB1 and Snail expressions in A549 cells. Further studies have confirmed CXCR4 as a target gene of miR-1246, and CXCR4 silence significantly abolished the promotion effect of miR-1246 suppression on cell invasion and EMT process in A549 cells. Besides, miR-1246 blocked JAK/STAT and PI3K/AKT signal pathways by regulation of CXCR4.

CONCLUSIONS

These results demonstrated that miR-1246 inhibited cell invasion and EMT process by targeting CXCR4 and blocking JAK/STAT and PI3K/AKT signal pathways in lung cancer cells.

Geographic distribution of the incidence of colorectal cancer in Iran: a population-based study

OBJECTIVES

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer death in the world. The aim of this study was to investigate the provincial distribution of the incidence of CRC across Iran.

METHODS

This epidemiologic study used data from the National Cancer Registry of Iran and the Center for Disease Control and Prevention of the Ministry of Health and Medical Education of Iran. The average annual age-standardized rate (ASR) for the incidence of CRC was calculated for each province.

RESULTS

We found that adenocarcinoma (not otherwise specified) was the most common histological subtype of CRC in males and females, accounting for 81.91 and 81.95% of CRC cases, respectively. Signet ring cell carcinoma was the least prevalent subtype of CRC in males and females and accounted for 1.5 and 0.94% of CRC cases, respectively. In patients aged 45 years or older, there was a steady upward trend in the incidence of CRC, and the highest ASR of CRC incidence among both males and females was in the age group of 80-84 years, with an ASR of 144.69 per 100,000 person-years for males and 119.18 per 100,000 person-years for females. The highest incidence rates of CRC in Iran were found in the central, northern, and western provinces. Provinces in the southeast of Iran had the lowest incidence rates of CRC.

CONCLUSIONS

Wide geographical variation was found in the incidence of CRC across the 31 provinces of Iran. These variations must be considered for prevention and control programs for CRC, as well as for resource allocation purposes.

The Incidence of Malignant Tumors in Environmentally Disadvantaged Regions of Kazakhstan

Objective:

To explore the prevalence of malignant tumors in the adult population through 2003-2014 in parts of the Aral Sea region: a zone of ecological disaster, a zone of ecological crisis and a zone of precritical conditions.

Methods:

The long-time average annual levels of cancer morbidity stratified by zones of the Aral Sea region and trends of long-time average annual incidence indicators of malignant tumors were identified. Leading cancer localizations in the adult population was established and associations between cancer incidence and environmental pollution were analyzed. In addition, associations between individual risk factors and cancer incidence in the adult population was established. Correlations between a hazard index and the cancer incidence in the adult population were calculated.

Results:

In all three Aral Sea regions, as well as in Zhanaarkinskii district, leading cancer in adult population was esophageal, stomach, tracheal, lung, hepatobiliary, and breast. Long-time average annual levels of cancer morbidity in adult population living in the Aral sea region is 1.5 times higher comparing to the control region. In particular, long-time average annual levels of cancer morbidity in adult population living in the zone of ecological disaster was 57.2% higher, in the zone of ecological crisis - 61.9% higher, and in the zone of precritical condition – 16.8% higher. Long-time average annual levels in the adult population of the Aral Sea region significantly exceeded control levels for brain and central nervous system cancer, cancer of bone and articular cartilage, and thyroid cancer.

Conclusion:

It has was established that the total cancer morbidity depended on the total hazard index associated with the inhalation of nickel and the combined cadmium intake (r=0.8).

Thyroid Cancer Epidemiology in Iran: a Time Trend Study

BACKGROUND

Considering the rising incidence of thyroid cancer worldwide, the aim of our study was to investigate the temporal trends in the incidence of this cancer in a large population of Iranian patients.

MATERIALS AND METHODS

We used the Iran Cancer Data System (ICDS) Registry to assess the thyroid cancer trend from 2004 to 2010 with regard to different genders, age groups, and morphologies. To do this we analyzed the data of 10,913 new cases of thyroid cancer that occurred during these years.

RESULTS

The incidence rate (per one year) of thyroid cancer was 2.20 per 100,000 persons between 2004 and 2010 in Iran. Papillary thyroid cancer was the most common histology type, with an annual rate of 0.29 in Iran. The highest rate of prevalence in thyroid cancer was observed at the age of 45 years at the time of diagnosis. We found a female-to-male ratio of 2 in Iran. A significant decrease was detected in the trend of thyroid cancer in children <19y, which was not correlated to the trend of older patients.

CONCLUSIONS

As expected, the trend of thyroid cancer increased over the 7 years, primarily contributed by papillary thyroid cancer. A rising pattern of incidence was seen in all the age groups except patients aged under 19 years.

Clinical, Histopathological and Molecular Characteristics of Metastatic Breast Cancer in North-Eastern Kazakhstan: a 10 Year Retrospective Study

Background:

Breast cancer (BC) is the top cancer among women worldwide and has been the most frequent malignancy among Kazakhstan women over the past few decades. Information on clinical and histopathological features of metastatic breast cancer (MBC), as well as the distribution of molecular subtypes is limited for Kazakh people.

Materials and Methods:

The present observational retrospective study was carried out at Regional Oncologic Dispensaries in the North-East Region of Kazakhstan (in Semey and Pavlodar cities). Сlinical and histopathological data were obtained for a total of 570 MBC patients in the 10 year period from 2004-2013, for whom data on molecular subtype were available for 253. Data from hospital charts were entered into SPSS 20 for analysis by one-way ANOVA analysis of associations of different variables with 1-5 year survival. Pearson correlation and linear regression models were used to examine the relation between parameters with a p-value < 0.05 considered statistically significant.

Results:

No significant relationships were evident between molecular subtype and survival, site of metastases, stage or ethnicity. Young females below the age of 44 were slightly more likely to have triple negative lesions. While the ductal type greatly predomonated, luminal A and B cases had a higher percentage with lobular morphology.

Conclusions:

In this select group of metastatice brease cancer, no links were noted for survival with molecular subtype, in contrast to much of the literature.

Cancer incidence and mortality data in Aktobe, west Kazakhstan, 2000-2010

The article provides an assessment of the dynamics of cancer incidence and mortality in the territory of Aktobe city for the period 2000-2010. The most common cancers were found in the lungs, stomach, esophagus and breast throughout the period, with slight increase in colon cancer and decrease in esophageal cancer being apparent. In an attempt to cast light on effects of environmental pollution, the authors also compared data on total emissions of chemicals into the air. While preliminary, the findings provide a basic picture of cancer burden in this industrialised city in Kazakhstan which should be followed up by more comprehensive monitoring.

Malignant Neoplasm Prevalence in the Aktobe Region of Kazakhstan

An oncopathological state assessment was conducted among adults, children and teenagers in Aktobe region for 2004-2013. Overall the burden of mortality was in the range of 94.8-100.2 per 100,000 population, without any obvious trend over time. Ranking by pathology, the highest incidences among women were registered for breast cancer (5.8-8.4), cervix uteri (2.9-4.6), ovary (2.4-3.6) and corpus uteri, stomach, esophagus, without any marked change over time except for a slight rise in cervical cancer rates. In males, the first place in rank was trachea, bronchus and lung, followed by stomach and esophagus, which are followed by bladder, lymphoid and hematopoietic tissues pathology. Agian no clear trends were apparent over time. In children, main localizations in cancer incidence blood (acute lymphocytic leukemia, lymphosarcoma, acute myeloid leukemia, Hodgkin's disease), brain and central nervous system, bones and articular cartilages, kidneys, and eye and it's appendages, in both sexes. Similarly, in young adults, the major percentage was in blood and lymphatic tissues (acute myeloid leukemia, acute lymphocytic leukemia, Hodgkin's disease) a significant percentage accruing to lymphosarcoma, lymphoma, other myeloid leukemia and hematological malignancies as well as tumors of brain and central nervous system, bones and articular cartilages. This initial survey provides the basis for more detailed investigation of cancer epidemiology in Aktobe, Kazakhstan.

Temporal Epidemiological Assessment of Colorectal Cancer Incidence and Mortality in East Kazakhstan, 2004-2013

Colorectal cancer incidence and mortality in Kazakhstan are relatively high but exact statistics have hitherto been lacking and trends over time are unclear. The present study was therefore undertaken to retrospectively assess data for East Kazakhstan, accessed from the central registration office, for the period 2004-2013. Approximate age standardized data for incidence and mortality were generated and compared across age groups, gender and year. It was determined that during the studied period 3,417 new cases of colorectal cancer were registered and 2,259 died of this pathology. Average cancer cancer incidence and mortality over the ten years were 24.1/105 and 15.9/105 respectively, and the overall ratio of mortality/incidence (M/I) was 0.69:1 (range 0.58-0.73). Both incidence and mortality tended to remain constant in both males and females. The male to female ratios also did not significantly vary over time but a trend for improvement of the mortality to incidence ratio was observed, especially for rectum. Whether this might be related to screening remains unclear. These preliminary data indicate that whereas colorectal cancer continues to be important, change in environmental factors are not having a great impact on incidence in East Kazakhstan.

Mexican breast cancer research output, 2003-2012

The objetive of this study was to explore a bibliometric approach to quantitatively assess current research trends with regard to breast cancer in Mexico. Articles were analyzed by scientific output and research performances of individuals, institutes, and collaborative countries with Mexico. Data were retrieved from the Web of Science database from 2003 to 2012; this was searched using different terms related to breast cancer, including "breast cancer", "mammary ductal carcinoma" and "breast tumour". Data were then extracted from each file, transferred to Excel charts and visualised as diagrams. A total of 256 articles were retrieved. The institutions with the majority of publications were the National Autonomous University of Mexico (22.3%), the National Institute of Cancerology (21.9%), and Social Security Mexican Institute (20.3%); clinical observation studies were the dominant investigation type (64%), and the main types of research were metabolics (24.2%) and pathology (21.5%). This article demonstrates the usefulness of bibliometrics to address key evaluation questions and to establish priorities, define future areas of research, and develop breast cancer control strategies in Mexico.