Vascular endothelial growth factor and psychosocial factors in colorectal cancer

Biobehavioral Pathways and Cancer Progression: Insights for Improving Well-Being and Cancer Outcomes

The relationship between psychosocial factors and cancer has intrigued people for centuries. In the last several decades there has been an expansion of mechanistic research that has revealed insights regarding how stress activates neuroendocrine stress-response systems to impact cancer progression. Here, we review emerging mechanistic findings on key pathways implicated in the effect of stress on cancer progression, including the cellular immune response, inflammation, angiogenesis, and metastasis, with a primary focus on the mediating role of the sympathetic nervous system. We discuss converging findings from preclinical and clinical cancer research that describe these pathways and research that reveals how these stress pathways may be targeted via pharmacological and mind-body based interventions. While further research is required, the body of work reviewed here highlights the need for and feasibility of an integrated approach to target stress pathways in cancer patients to achieve comprehensive cancer treatment.

Integrative Treatment for Colorectal Cancer: A Comprehensive Approach

A comprehensive approach to integrative treatment of colorectal cancer (CRC) patients involves three spheres of intervention: lifestyle, biology, and conventional treatment. Individualization of treatment is emphasized. The lifestyle sphere includes nutritional therapies, biobehavioral strategies with circadian interventions, and physical care modalities. The biology sphere comprises six host factors in the patient's internal biochemical environment or "terrain": inflammation, glycemia, oxidative stress, immune dysregulation, coagulopathy, and stress chemistries. Laboratory testing of these factors guides integrative lifestyle and supplement recommendations. The conventional treatment sphere includes individualized lifestyle recommendations, and supplements or drugs used to enhance tolerability or effectiveness of conventional treatments. Innovative strategies are implemented, including chronomodulated chemotherapy, chemosensitivity testing, and using results of molecular genomic testing to guide nutritional infusions and supplement recommendations. In the lifestyle sphere, substantial evidence from cohort studies supports recommendations for a diet that emphasizes plant and fish proteins, healthful fats in amounts that are tailored to the clinical circumstance of the patient, and carbohydrates based on unrefined whole grains, vegetables and whole fruits. High glycemic diets and refined carbohydrates, especially sugar-sweetened beverages, should be avoided. Biobehavioral strategies include practice of the relaxation response and related approaches. In addition, specific strategies to promote robust circadian organization (CO) are used to combat quality of life concerns and worsened survival that accompany disrupted CO. Physical activity, including aerobic activity and muscle strengthening, is recommended at all disease stages. In the biology sphere, supplements and lifestyle recommendations for inflammation and glycemia are discussed. In the conventional treatment sphere, supplements and innovative and complementary therapies that may remedy treatment toxicities are reviewed. Approaching CRC treatment with a comprehensive, individualized intervention enables safe and beneficial outcomes in this patient population, which can vary widely in individual biology, treatment toxicities, and disease complications. Further research in integrative therapies for CRC patients is needed.

Exhaled nitric oxide and vascular endothelial growth factor as predictors of cold symptoms after stress

OBJECTIVE

Prior research has demonstrated that psychosocial stress is associated with respiratory infections. Immunologic, endocrine, and cardiovascular predictors of such infections have been explored with varying success. We therefore sought to study the unexplored role of airway mucosal immunity factors, nitric oxide (NO) and vascular endothelial growth factor (VEGF). NO is secreted by airway epithelial cells as part of the first line of defense against bacteria, viruses, and fungi. VEGF is expressed by mast cells in respiratory infections and recruits immune cells to infected sites, but in excess lead to vulnerability of the airway epithelium.

METHODS

In this proof-of-concept study we measured exhaled NO, exhaled breath condensate (EBC) VEGF, salivary VEGF, and salivary cortisol in 36 students undergoing final academic examinations at three occasions: a low-stress baseline during the term, an early phase of finals, and a late phase of finals. Participants also reported on cold symptoms at these time points and approximately 5 and 10days after their last academic examination.

RESULTS

Higher baseline NO was associated with fewer cold symptoms after stress, whereas higher baseline VEGF in EBC and saliva were associated with more cold symptoms after stress. Perceived stress at baseline as well as salivary VEGF and cortisol late in the finals also contributed to the prediction of later cold symptoms.

CONCLUSION

Basal levels of NO and VEGF may inform about mucosal immunocompetence and add to preventative treatments against airway infections from periods of stress in daily life.

Study protocol on comparative effectiveness of mindfulness meditation and qigong on psychophysiological outcomes for patients with colorectal cancer: a randomized controlled trial

Background

Colorectal cancer imposes threats to patients’ well-being. Although most physical symptoms can be managed by medication, psychosocial stressors may complicate survival and hamper quality of life. Mindfulness and Qigong, two kinds of mind-body exercise rooted in Eastern health philosophy, has been found effective in symptoms management, improving mental health, and reducing stress. With these potential benefits, a randomized controlled trial (RCT) is planned to investigate the comparative effectiveness of mindfulness and Baduanjin intervention on the bio-psychosocial wellbeing of people with colorectal cancer.

Methods/ design

A 3-arm RCT with waitlist control design will be used in this study. One hundred eighty-nine participants will be randomized into (i) Mindfulness, (ii) Baduanjin, or (iii) waitlist control groups. Participants in both the Baduanjin and mindfulness groups will receive 8-weeks of specific intervention. All three groups will undergo four assessment phases: (i) at baseline, (ii) at 4-week, (iii) at 8-week (post-intervention), and 6-month post-intervention (maintenance). All participants will be assessed in terms of cancer-related symptoms and symptom distress, mental health status, quality of life, stress level based on physiological marker.

Discussion

Based on prior research studies, participants in both the mindfulness and Baduanjn intervention group are expected to have better symptoms management, lower stress level, better mental health, and higher level of quality of life than the control group. This study contributes to better understanding on the common and unique effectiveness of mindfulness and Baduanjin qigong, as such patients and qualified healthcare professionals can select or provide practices which will produce maximum benefits, satisfaction, adherence, and sustainability.

Trial registration

The trial has been registered in the Clinical Trials Centre of the University of Hong Kong (HKCTR-2198) on 08 March 2017.

Biobehavioral approaches to cancer progression and survival: Mechanisms and interventions

Over the last decade, there have been groundbreaking strides in our understanding of the multiple biological pathways by which psychosocial and behavioral factors can affect cancer progression. It is now clear that biobehavioral factors not only affect cellular immunity but both directly and indirectly modulate fundamental processes in cancer growth, including inflammation, angiogenesis, invasion, and metastasis. There is also an emerging understanding of how psychological and behavioral factors used in interventions can impact these physiological processes. This review outlines our current understanding of the physiological mechanisms by which psychological, social, and behavioral processes can affect cancer progression. The intervention literature is discussed, along with recommendations for future research to move the field of biobehavioral oncology forward.

Effects of academic exam stress on nasal leukotriene B4 and vascular endothelial growth factor in asthma and health

OBJECTIVE

To examine the effect of final exam stress on the concentrations of leukotriene B4 (LTB4) and vascular endothelial growth factor (VEGF) in the upper airways among healthy and asthmatic individuals.

METHOD

Nasal samples were collected from 12 individuals with asthma and 23 healthy controls early and late in a final exam period, and during a low-stress period in the semester. We determined LTB4 and VEGF concentrations using Enzyme-Linked Immunoassays.

RESULTS

Mixed effects analysis of variance models showed that asthmatic participants with allergies in contrast to healthy individuals experienced a decrease in nasal LTB4 during the final exam period as compared to mid-semester (low stress period). There were no significant changes in nasal VEGF across the observation period. Changes in nasal LTB4 and VEGF were not associated with salivary cortisol, exhaled nitric oxide, or spirometric lung function.

CONCLUSIONS

Our results suggest that nasal LTB4 concentrations change in periods of psychological stress for asthmatic individuals with allergies.

Targeted drugs and Psycho-oncological intervention for breast cancer patients

Personalized medicine is a new field based on molecular biology and genomics in which targeted tumor therapies are administered to patients. Psycho-oncology is a complementary approach that considers social and psychological aspects of patients as part of the treatments for cancer patients.

The aim of this mini-review is to weigh clinical benefits for breast cancer patients of both treatments and possibily enhance benefits by modulating the use of both interventions. We have compared and evaluated on the one hand the use of anti Vascular Endothelial Growth Factor and, on the other hand, psycho-oncological interventions in metastatic and non-metastatic breast cancer patients.

Both treatments did not increase survival of metastatic breast cancer patients, while in a selected study psycho-oncological interventions extended lifespan of non-metastatic breast cancer patients and ameliorate psychological and social factors of metastatic breast cancer patients. Because the two approaches address completely different aspects of cancer patients, if the comparison is limited to the extension of survival, the value of these two treatments cannot be assessed and compared.

It is likely that by comparing patients reported outcomes, possibly by using standardized Quality of Life questionnaires, both patients and health care providers can weigh the benefits of the two treatments. It is therefore important to evaluate the use of cancer patients’ quality of life measures as a mean to improve their experiences about life and treatment, and possibly to extend their survival.

The influence of marital status on stage at diagnosis and survival of patients with colorectal cancer

Marital status was found to be an independent prognostic factor for survival in various cancer types, but it hasn’t been fully studied in colorectal cancer (CRC). The Surveillance, Epidemiology and End Results database was used to compare survival outcomes with marital status in each stage. In total, 112, 776 eligible patients were identified. Patients in the widowed group were more frequently elderly women, more common of colon cancer, and more stage I/II in tumor stage (P < 0.001), but the surgery rate was comparable to that for the married group (94.72% VS 94.10%). Married CRC patients had better 5year cause-specific survival (CSS) than those unmarried (P < 0.05). Further analysis showed that widowed patients always presented the lowest CSS compared with that of other’ group. Widowed patients had 5% reduction 5-year CSS compared with married patients at stage I (94.8% vs 89.8%, P < 0.001), 9.4% reduction at stage II (85.9% vs 76.5%, P < 0.001), 16.7% reduction at stage III (70.6% vs 53.9%, P < 0.001) and 6.2% reduction at stage IV(14.4% VS 8.2%, P < 0.001). These results showed that unmarried patients were at greater risk of cancer specific mortality. Despite favorable clinicpathological characteristics, widowed patients were at highest risk of death compared with other groups.

Psychological states, serum markers and survival: associations and predictors of survival in patients with renal cell carcinoma

This study sought to determine if there was an association between prognostic-based serum biomarkers, survival, and psychosocial factors in patients with metastatic renal cell carcinoma. Associations were found between psychosocial factors and biomarker levels (hemoglobin with depressive symptoms (r = -0.29), positive affect (r = 0.30), social support (r = 0.19), and perceived stress (r = -0.27); albumin with depressive symptoms (r = -0.19), positive affect (r = 0.22), and social support (r = 0.20); alkaline phosphatase with depressive symptoms (r = 0.21), all p values <0.05. After adjustment for disease-related risk factors, only the associations between positive affect and perceived stress with hemoglobin remained significant (p's < 0.05). Positive affect (HR = 0.90; 95% CI = 0.83, 0.97; p = 0.009) and depressive symptom total scores (HR = 1.03; 95% CI = 1.01, 1.06; p = 0.013), and alkaline phosphatase (HR 2.72; 95% CI = 1.41, 5.24; p = 0.003) were associated with survival. This study suggests that measures of positive and negative psychological outlook may contribute differently to health, well-being, and survival.

Integrative therapies in cancer: modulating a broad spectrum of targets for cancer management

Integrative medicine is an approach to health and healing that "makes use of all appropriate therapeutic approaches, health care professionals, and disciplines to achieve optimal health and healing." A comprehensive integrative medicine intervention for cancer patients typically includes nutritional counseling, biobehavioral strategies, and promotion of physical activity, as well as dietary supplements including herbs, nutraceuticals, and phytochemicals. A broad-spectrum intervention of this type may contribute uniquely to improvement in cancer outcomes through its impact on a wide variety of relevant molecular targets, including effects on multiple cancer hallmarks. Hallmarks that may be particularly affected include genetic instability, tumor-promoting inflammation, deregulated metabolism, and immune system evasion. Because of their susceptibility to manipulation by diet, exercise, and supplementation, these may be characterized as metabolic hallmarks. Research on the use of comprehensive integrative approaches can contribute to the development of systems of multitargeted treatment regimens and would help clarify the combined effect of these approaches on cancer outcomes.

Depressive symptoms and cytokine levels in Serum and Tumor Tissue in patients with an Astrocytoma: a pilot study

Background

Preoperative depressive symptoms are associated with poor outcomes in patients with an astrocytoma. Cytokines are associated with depressive symptoms in the general population and are important mediators of tumor growth and progression.

The aims of this study were to: (1) characterize depressive symptoms, other treatment-related symptoms and biological mediators; and (2) determine whether preoperative depressive symptoms were associated with the selected biological mediators.

Methods

A prospective, exploratory study was carried out among 22 patients with a high-grade astrocytoma. Self-report questionnaires and peripheral blood samples were collected on the day of surgery. Tumor tissue was collected intraoperatively. Self-report questionnaires were assessed at 3, 6, 9, and 12-months postoperatively.

Results

In circulation, serum IL-8 was inversely correlated with depressive symptoms while IL-17 measured in tumor tissue supernatant was inversely correlated with depressive symptoms. Depressive symptoms showed a significant increase at 12 months from baseline levels and were positively associated with treatment-related symptoms at 3 months and symptom distress at 12 months post-surgery.

Conclusions

In this pilot study, depressive symptoms were negatively associated with IL-8 in serum and IL-17 in tumor tissue. The changes among depressive symptoms, treatment-related symptoms and symptom distress highlight the need for multi-faceted symptom management strategies over the treatment trajectory in this patient population.

Baseline quality of life factors predict long term survival after elective resection for colorectal cancer

BACKGROUND

Studies have shown an association between baseline quality of life (Qol) and survival in advanced cancers. The aim of this study was to investigate their predictive value in long term survival after elective colorectal cancer resection.

METHODS

A consecutive series of patients undergoing elective colorectal cancer surgery for nonmetastatic disease were recruited in 2003/04. Patients completed standardized quality of life questionnaires (HADS, FACTC, MRS, and PANAS) prior to and 6 weeks after surgery. Univariate (log-rank test) and multivariate analyses (Cox proportional hazards) were performed to predict long term survival.

RESULTS

Ninety-seven patients met the inclusion criteria. Sixty-five (67%) were male and the median age of the group was 70 years. Forty-six (47.5%) patients had died and the mean survival was 1,741 days (median 2159, range 9-2923 days). Preoperative mood rating scale and functional assessment of cancer therapy-colorectal FACT C emotional well-being and postoperative FACT C additional concerns were independent predictors of long term survival.

CONCLUSION

Incorporating psychosocial measures in preoperative assessment of cancer patients could help to identify patients who require assessment with a view to implementing psychosocial interventions. These active interventions to maximize mood and well-being should form an integral part of multidisciplinary treatment in these patients.

Psychosocial functioning and vascular endothelial growth factor in patients with head and neck cancer

BACKGROUND

Psychosocial functioning is associated with vascular endothelial growth factor (VEGF) in various patient populations. This study examined whether psychosocial functioning in patients with head and neck squamous cell carcinoma (HNSCC) is associated with tumor VEGF expression, a protein that stimulates angiogenesis and is associated with poor prognosis.

METHODS

Forty-two newly diagnosed patients completed assessments of psychosocial functioning (ie, depressive symptoms, perceived stress, anxiety, social support) before surgery. Tumor samples were obtained for VEGF analysis and human papillomavirus (HPV)-typing.

RESULTS

Poorer psychosocial functioning was associated with greater VEGF expression controlling for disease stage (odds ratio [OR], 4.55; 95% confidence interval [CI], 1.72-12.0; p < .01). When examined by HPV status, the association between psychosocial functioning and VEGF remained significant among patients who were HPV negative (OR, 5.50; 95% CI, 1.68-17.3; p < .01), but not among patients who were HPV positive.

CONCLUSION

These findings inform our understanding of the biobehavioral pathways that may contribute to poor outcomes in non-HPV-associated HNSCCs.

Endothelial progenitor cells may participate in stress-induced tumour angiogenesis

Epidemiological and animal studies have suggested that chronic stress promotes tumourigenesis by promoting tumour angiogenesis. However, underlying mechanisms have not been fully elucidated. Endothelial progenitor cells (EPCs) are a group of bone marrow-derived cells that have an important function in neovascularisation of various tumour growths. In this study, chronic stress was hypothesised to increase tumour angiogenesis via sympathetic neurotransmitter-induced activation of EPCs through α1 adrenoreceptor (AR)-extracellular regulated protein kinases and β2 AR-endothelial nitric oxide synthase signal pathways. This hypothesis should be tested in several clinical and animal studies. Results may have implications on the development of new anti-tumour drugs.

The effect of academic exam stress on mucosal and cellular airway immune markers among healthy and allergic individuals

Research suggests that psychological stress can exacerbate allergies, but relatively little is known about the effect of stress on mucosal immune processes central to allergic pathophysiology. In this study, we quantified vascular endothelial growth factor (VEGF), interferon gamma (IFN-γ), and interleukin-4 concentrations in saliva (S) and exhaled breath condensate (EBC) during final exams and at midsemester among 23 healthy and 21 allergic rhinitis individuals. IFN-γs decreased during exams for both groups while VEGF(EBC) increased (and increases in VEGFs were a trend). Elevated negative affect ratings predicted higher VEGF(EBC) in allergic individuals. IFN-γ(EBC) increased in healthy individuals early during exams and then decreased, while allergic individuals showed a decrease in IFN-γ(EBC) throughout final exams. These findings suggest that psychological stress can suppress cellular immune function among allergic individuals while increasing VEGF.

Relationship between circulating cytokine levels and physical or psychological functioning in patients with advanced cancer

OBJECTIVE

To investigate the relation between functional impairments of cancer patients and circulating cytokines using a multiplex technique.

DESIGN AND METHODS

50 patients with cancer were assessed using the quality of life (QOL) questionnaire. 27 plasma cytokine levels were determined by using the Bio-Plex array system. The relation to QOL scores was assessed using Chi-square test for categorical variables and univariate linear regression analysis for cytokine levels.

RESULTS

Multivariate analysis showed that interleukin-6 (IL-6) level is a significant independent determinant of physical (β=-0.238, P=0.0126) and cognitive functioning (β=-0.462, P=0.0006) and that vascular endothelial growth factor (VEGF) level is a significant independent determinant of emotional functioning (β=-0.414, P=0.039).

CONCLUSION

This study, in which 27 cytokines are simultaneously tested with cutting edge technology, demonstrates that plasma IL-6 and VEGF are significant independent determinants of functional impairments in patients with cancer.

Increased plasma VEGF levels in major depressive or manic episodes in patients with mood disorders

BACKGROUND

The neurotrophic hypothesis suggests that mood disorders are associated with dysfunction of neuronal networks under the influence of neurotrophic factors. Vascular endothelial growth factor (VEGF) is a neurotrophic factor as well as an angiogenic cytokine.

METHODS

We examined plasma VEGF levels in 35 unipolar patients who were diagnosed with current major depressive disorder (MDD), 35 bipolar patients who were diagnosed with bipolar I disorder, manic episode (BM), and 60 healthy controls. The severity of depressive or manic symptoms was measured using the Hamilton Depression Rating Scale (HDRS) or the Young Mania rating scale (YMRS), respectively.

RESULTS

Plasma VEGF levels were 163.28±135.33 pg/mL in MDD patients, 199.82±182.59 pg/mL in BM patients, and 110.05±109.57 pg/mL in healthy controls. Both MDD and BM patients had significantly higher VEGF levels than healthy controls when controlling for BMI as a covariate (p=0.010). Patients' VEGF levels were not correlated with either HDRS or YMRS scores.

LIMITATIONS

We assessed plasma VEGF levels at one time point, and we did not determine the source of VEGF in our samples.

CONCLUSIONS

Plasma VEGF levels were elevated in patients with acute episodes of major depressive disorder and bipolar disorder. Such an alteration of VEGF in acute episode, mood disorders may be associated with a neuroprotective role for VEGF.

Impact of stress on cancer metastasis

The influence of psychosocial factors on the development and progression of cancer has been a longstanding hypothesis since ancient times. In fact, epidemiological and clinical studies over the past 30 years have provided strong evidence for links between chronic stress, depression and social isolation and cancer progression. By contrast, there is only limited evidence for the role of these behavioral factors in cancer initiation. Recent cellular and molecular studies have identified specific signaling pathways that impact cancer growth and metastasis. This article provides an overview of the relationship between psychosocial factors, specifically chronic stress, and cancer progression.

Biobehavioral factors and cancer progression: physiological pathways and mechanisms

Epidemiologic evidence increasingly has supported the role of biobehavioral risk factors such as social adversity, depression, and stress in cancer progression. This review describes in vitro, in vivo, and clinical studies demonstrating relationships between such processes and pathways involved in cancer progression. These include effects on the cellular immune response, angiogenesis, invasion, anoikis, and inflammation. Biobehavioral factors have been shown to contribute to the cross talk between tumor and host cells in the tumor microenvironment, and stress effects on host cells such as macrophages seem to be critical for many pathways involved in tumor progression. Some effects are bidirectional in that tumor-derived inflammation seems to affect central nervous system processes, giving rise to vegetative symptoms and contributing to dysregulation of the hypothalamic-pituitary-adrenal axis with downstream effects on inflammatory control. Findings to date are reviewed, and fruitful areas for future research are discussed.

Relationship between loneliness and proangiogenic cytokines in newly diagnosed tumors of colon and rectum

OBJECTIVE

To investigate the association of serum levels of proangiogenic cytokines with different indices of social support and loneliness by measuring the levels of expression of two important proangiogenic cytokines, vascular endothelial growth factor (VEGF), and interleukin-6 in tumors of colon and rectum. Lack of social support has been prospectively associated with cancer progression.

METHODS

Fifty-one newly diagnosed patients with colorectal tumors (mean age, 68.3 years) completed two measures of loneliness 1 to 2 days before their surgical treatment. The first was an explicit self-report questionnaire, which tapped into negative feelings as a result of low social support. The second was a standardized computer-based task, which measured loneliness implicitly. Immunohistochemical analyses were performed on tumor tissues post surgery to determine the expression of cytokines.

RESULTS

Logistic regression showed that higher levels of implicit loneliness independently predicted stronger expression of VEGF, controlling for Dukes stage and explicit loneliness, both of which were nonsignificant predictors. No significant relationships were found between the loneliness measures and interleukin-6.

CONCLUSIONS

The results of this study suggest VEGF to be an angiogenic mechanism through which loneliness may lead to worse cancer-related outcomes. Implications are discussed in terms of devising targeted psychosocial and immunotherapeutic interventions for cancer patients with low social support.

Angiogenic factors in patients with current major depressive disorder comorbid with borderline personality disorder

BACKGROUND

Major depression has been associated with endocrine and immune alterations, in particular a dysregulation of the hypothalamus-pituitary-adrenal system with subsequent hypercortisolism and an imbalance of pro- and anti-inflammatory cytokines. Recent studies suggest that vascular endothelial growth factor (VEGF), a cytokine involved in angiogenesis and neurogenesis, may also be dysregulated during stress and depression. These observations prompted us to examine VEGF and other angiogenic factors in patients with major depressive disorder.

METHODS

Twelve medication-free female patients with a major depressive episode in the context of borderline personality disorder (MDD/BPD) and twelve healthy women were included. Concentrations of VEGF, VEGF receptors 1 and 2, basic fibroblast growth factor-2 (FGF-2), hepatocyte growth factor (HGF), angiopoetin-2, interleukin-8 (IL-8) and transforming growth factor-beta1 (TGF-beta1) were determined from serum profiles.

RESULTS

Increased concentrations of VEGF and FGF-2 were found in MDD/BPD patients compared to the healthy comparator group. No group differences were found concerning the other angiogenic factors examined.

CONCLUSION

Depressive episodes in the context of borderline personality disorder may be accompanied by increased serum concentrations of VEGF and FGF-2. Similar findings have been observed in patients with major depression without a borderline personality disorder. A dysregulation of angiogenic factors may be another facet of the endocrine and immunologic disturbances frequently seen in patients with depressive episodes.

VEGF serum levels in depressed patients during SSRI antidepressant treatment

Recent evidence indicates that the vascular endothelial growth factor (VEGF) may be involved in the neuronal mechanisms underlying both the depression aetiology and the response to pharmacological and non pharmacological antidepressant treatments. To investigate whether VEGF peripheral levels are altered in depression and are modulated by antidepressant therapies, we analyzed the serum VEGF concentrations in 25 subjects affected by major depression (MD) before (T0) and after 8 (T8) and 12 (T12) weeks of escitalopram treatment. No significant alterations in VEGF serum levels were found at T0, even considering possible effects of confounders such as gender and smoking habit (r2=0.227 p=0.74). No changes appeared during the treatment (F(1.83, 43.86)=0.962; p=0.383) and there was no correlation between percentage VEGF variations at T12 and symptoms improvements (p=0.823). The present work represents the first report on the evaluation of serum VEGF levels in MD patients. However, before discarding serum VEGF as a biochemical marker in the diagnosis and treatment of depression, our negative results need to be confirmed in larger patient samples stratified for clinical characteristics, co-morbidities, cardiovascular diseases and confounding factors.

Expression of vascular endothelial growth factor expression and its relation with growth, invasion and metastasis of human colorectal cancer

AIM: To explore the relations of vascular endothelial growth factor (VEGF) expression with the growth, invasion and metastasis of colorectal cancer.

METHODS: We collected 23 fresh colorectal cancerous, distal cancerous tissues resected during operation, 16 colon polyps and 45 serum samples from colon cancer patients. The expression of VEGF in colorectal tissues and serum samples was detected by nested reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The relationship was also analyzed between VEGF expression and Duke's staging.

RESULTS: The expression of VEGF mRNA was significantly higher in the colorectal cancer tissues than that in the distal cancerous tissues or colon polyps (65.22% vs 21.74%, 18.75%, both P < 0.01). VEGF mRNA expression was positive in 3 patients (37.5%) with Duke's stage A or B, and it was positive in 12 patients with (80.0%) stage C or D; there was significant difference between them (P < 0.05). The level of serum VEGF was markedly higher in patients with stage C or D than that in patients with stage A or B (716.71 + 229.39 ng/L vs 312.30 + 103.61 ng/L, P < 0. 01).

CONCLUSION: VEGF can serve as an index in predicting the growth, invasion and metastasis of colorectal cancer.