Cancer Medicine

Natural bicyclic sesquiterpenes, β‐caryophyllene (BCP) and β‐caryophyllene oxide (BCPO), are present in a large number of plants worldwide. Both BCP and BCPO (BCP(O)) possess significant anticancer activities, affecting growth and proliferation of numerous cancer cells. Nevertheless, their antineoplastic effects have hardly been investigated in vivo. In addition, both compounds potentiate the classical drug efficacy by augmenting their concentrations inside the cells. The mechanisms underlying the anticancer activities of these sesquiterpenes are poorly described. BCP is a phytocannabinoid with strong affinity to cannabinoid receptor type 2 (CB₂), but not cannabinoid receptor type 1 (CB₁). In opposite, BCP oxidation derivative, BCPO, does not exhibit CB_1/2 binding, thus the mechanism of its action is not related to endocannabinoid system (ECS) machinery. It is known that BCPO alters several key pathways for cancer development, such as mitogen‐activated protein kinase (MAPK), PI3K/AKT/mTOR/S6K1 and STAT3 pathways. In addition, treatment with this compound reduces the expression of procancer genes/proteins, while increases the levels of those with proapoptotic properties. The selective activation of CB₂ may be considered a novel strategy in pain treatment, devoid of psychoactive side effects associated with CB₁ stimulation. Thus, BCP as selective CB₂ activator may be taken into account as potential natural analgesic drug. Moreover, due to the fact that chronic pain is often an element of cancer disease, the double activity of BCP, anticancer and analgesic, as well as its beneficial influence on the efficacy of classical chemotherapeutics, is particularly valuable in oncology. This review is focused on anticancer and analgesic activities of BCP and BCPO, the mechanisms of their actions, and potential therapeutic utility.

The aim of this study was to update a previous scoring system for patients with skeletal metastases, that was proposed by Katagiri et al. in 2005, by introducing a new factor (laboratory data) and analyzing a new patient cohort. Between January 2005 and January 2008, we treated 808 patients with symptomatic skeletal metastases. They were prospectively registered regardless of their treatments, and the last follow‐up evaluation was performed in 2012. There were 441 male and 367 female patients with a median age of 64 years. Of these patients, 749 were treated nonsurgically while the remaining 59 underwent surgery for skeletal metastasis. A multivariate analysis was conducted using the Cox proportional hazards model. We identified six significant prognostic factors for survival, namely, the primary lesion, visceral or cerebral metastases, abnormal laboratory data, poor performance status, previous chemotherapy, and multiple skeletal metastases. The first three factors had a larger impact than the remaining three. The prognostic score was calculated by adding together all the scores for individual factors. With a prognostic score of ≥7, the survival rate was 27% at 6 months, and only 6% at 1 year. In contrast, patients with a prognostic score of ≤3 had a survival rate of 91% at 1 year, and 78% at 2 years. Comparing the revised system with the previous one, there was a significantly lower number of wrongly predicted patients using the revised system. This revised scoring system was able to predict the survival rates of patients with skeletal metastases more accurately than the previous system and may be useful for selecting an optimal treatment.

Of all the gynecologic tumors, ovarian cancer (OC) is known to be the deadliest. Advanced‐stages of OC are linked with high morbidity and low survival rates despite the immense amount of research in the field. Shortage of promising screening tools for early‐stage detection is one of the major challenges linked with the poor survival rate for patients with OC. In OC, therapeutic management is used with multidisciplinary approaches that includes debulking surgery, chemotherapy, and (rarely) radiotherapy. Recently, there is an increasing interest in using immunomodulation for treating OC. Relapse rates are high in this malignancy and averages around every 2‐years. Further treatments after the relapse are more intense, increasing the toxicity, resistance to chemotherapy drugs, and financial burden to patients with poor quality‐of‐life. A procedure that has been studied to help reduce the morbidity rate involves pre‐sensitizing cancer cells with standard therapy in order to produce optimal results with minimum dosage. Utilizing such an approach, platinum‐based agents are effective due to their increased response to platinum‐based chemotherapy in relapsed cases. These chemo‐drugs also help address the issue of drug resistance. After conducting an extensive search with available literature and the resources for clinical trials, information is precisely documented on current research, biomarkers, options for treatment and clinical trials. Several schemes for enhancing the therapeutic responses for OC are discussed systematically in this review with an attempt in summarizing the recent developments in this exciting field of translational/clinical research.

Angiogenesis has been regarded as essential for tumor growth and progression. Studies of many human tumors, however, suggest that their microcirculation may be provided by nonsprouting vessels and that a variety of tumors can grow and metastasize without angiogenesis. Vessel co‐option, where tumor cells migrate along the preexisting vessels of the host organ, is regarded as an alternative tumor blood supply. Vessel co‐option may occur in many malignancies, but so far mostly reported in highly vascularized tissues such as brain, lung, and liver. In primary and metastatic lung cancer and liver metastasis from different primary origins, as much as 10–30% of the tumors are reported to use this alternative blood supply. In addition, vessel co‐option is introduced as a potential explanation of antiangiogenic drug resistance, although the impact of vessel co‐option in this clinical setting is still to be further explored. In this review we discuss tumor vessel co‐option with specific examples of vessel co‐option in primary and secondary tumors and a consideration of the clinical implications of this alternative tumor blood supply.

Successful treatment of cancer remains a challenge, due to the unique pathophysiology of solid tumors, and the predictable emergence of resistance. Traditional methods for cancer therapy including radiotherapy, chemotherapy, and immunotherapy all have their own limitations. A novel approach is bacteriotherapy, either used alone, or in combination with conventional methods, has shown a positive effect on regression of tumors and inhibition of metastasis. Bacteria‐assisted tumor‐targeted therapy used as therapeutic/gene/drug delivery vehicles has great promise in the treatment of tumors. The use of bacteria only, or in combination with conventional methods was found to be effective in some experimental models of cancer (tumor regression and increased survival rate). In this article, we reviewed the major advantages, challenges, and prospective directions for combinations of bacteria with conventional methods for tumor therapy.

The activation of the transcription factor hypoxia‐inducible factor‐1 (HIF‐1) plays an essential role in tumor development, tumor progression, and resistance to chemo‐ and radiotherapy. In order to identify compounds targeting the HIF pathway, a small molecule library was screened using a luciferase‐driven HIF‐1 reporter cell line under hypoxia. The high‐throughput screening led to the identification of a class of aminoalkyl‐substituted compounds that inhibited hypoxia‐induced HIF‐1 target gene expression in human lung cancer cell lines at low nanomolar concentrations. Lead structure BAY 87‐2243 was found to inhibit HIF‐1α and HIF‐2α protein accumulation under hypoxic conditions in non‐small cell lung cancer (NSCLC) cell line H460 but had no effect on HIF‐1α protein levels induced by the hypoxia mimetics desferrioxamine or cobalt chloride. BAY 87‐2243 had no effect on HIF target gene expression levels in RCC4 cells lacking Von Hippel–Lindau (VHL) activity nor did the compound affect the activity of HIF prolyl hydroxylase‐2. Antitumor activity of BAY 87‐2243, suppression of HIF‐1α protein levels, and reduction of HIF‐1 target gene expression in vivo were demonstrated in a H460 xenograft model. BAY 87‐2243 did not inhibit cell proliferation under standard conditions. However under glucose depletion, a condition favoring mitochondrial ATP generation as energy source, BAY 87‐2243 inhibited cell proliferation in the nanomolar range. Further experiments revealed that BAY 87‐2243 inhibits mitochondrial complex I activity but has no effect on complex III activity. Interference with mitochondrial function to reduce hypoxia‐induced HIF‐1 activity in tumors might be an interesting therapeutic approach to overcome chemo‐ and radiotherapy‐resistance of hypoxic tumors.

Prostate cancer is the third most common causes of death from cancer in men. Our previous study demonstrated that lncRNA PVT1 was overexpressed and played an oncogenic role in the progression of prostate cancer. However, the molecular mechanism of modulating the prostate cancer tumorigenesis was still unknown. In this study, we aim to investigate the interaction between PVT1 and miR‐146a in prostate cancer and reveal the potential mechanism in prostate cancer carcinogenesis. The expression level of miR‐146a was assessed by quantitative RT‐PCR. The correlation analysis and methylation status analysis was made to confirm the interaction between PVT1 and miR‐146a. Biological function analysis was performed through gain‐of‐function and loss‐of‐function strategies. Our results showed that miR‐146a was downregulated and negatively correlated with PVT1 level in prostate cancer. PVT1 mediated miR‐146a expression by inducing the methylation of CpG Island in its promoter. miR‐146a overexpression eliminated the effects of PVT1 knockdown on prostate cancer cells. PVT1 regulated prostate cancer cell viability and apoptosis depending on miR‐146a. Our study suggested a regulatory relationship between lncRNA PVT1 and miR‐146a during the process of the prostate cancer tumorigenesis. PVT1 regulated prostate cancer cell viability and apoptosis depending on miR‐146a. It would contribute to the diagnosis, treatment and prognosis of prostate cancer.

Cancer cells exhibit a variety of features indicative of atypical nuclei. However, the molecular mechanisms underlying these phenomena remain to be elucidated. The linker of nucleoskeleton and cytoskeleton (LINC) complex, a nuclear envelope protein complex consisting mainly of the SUN and nesprin proteins, connects nuclear lamina and cytoskeletal filaments and helps to regulate the size and shape of the nucleus. Using immunohistology, we found that a nuclear lamina component, lamin A/C and all of the investigated LINC complex components, SUN1, SUN2, and nesprin‐2, were downregulated in human breast cancer tissues. In the majority of cases, we observed lower expression levels of these analytes in samples' cancerous regions as compared to their cancer‐associated noncancerous regions (in cancerous regions, percentage of tissue samples exhibiting low protein expression: lamin A/C, 85% [n = 73]; SUN1, 88% [n = 43]; SUN2, 74% [n = 43]; and nesprin‐2, 79% [n = 53]). Statistical analysis showed that the frequencies of recurrence and HER2 expression were negatively correlated with lamin A/C expression (P < 0.05), and intrinsic subtype and ki‐67 level were associated with nesprin‐2 expression (P < 0.05). In addition, combinatorial analysis using the above four parameters showed that all patients exhibited reduced expression of at least one of four components despite the tumor's pathological classification. Furthermore, several cultured breast cancer cell lines expressed less SUN1, SUN2, nesprin‐2 mRNA, and lamin A/C compared to noncancerous mammary gland cells. Together, these results suggest that the strongly reduced expression of LINC complex and nuclear lamina components may play fundamental pathological functions in breast cancer progression.

Primary clear cell renal cell carcinoma (ccRCC) genetic heterogeneity may lead to an underestimation of the mutational burden detected from a single site evaluation. We sought to characterize the extent of clonal branching involving key tumor suppressor mutations in primary ccRCC and determine if genetic heterogeneity could limit the mutation profiling from a single region assessment. Ex vivo core needle biopsies were obtained from three to five different regions of resected renal tumors at a single institution from 2012 to 2013. DNA was extracted and targeted sequencing was performed on five genes associated with ccRCC (von‐Hippel Lindau [VHL], PBRM1, SETD2, BAP1, and KDM5C). We constructed phylogenetic trees by inferring clonal evolution based on the mutations present within each core and estimated the predictive power of detecting a mutation for each successive tumor region sampled. We obtained 47 ex vivo biopsy cores from 14 primary ccRCC's (median tumor size 4.5 cm, IQR 4.0–5.9 cm). Branching patterns of various complexities were observed in tumors with three or more mutations. A VHL mutation was detected in nine tumors (64%), each time being present ubiquitously throughout the tumor. Other genes had various degrees of regional mutational variation. Based on the mutations' prevalence we estimated that three different tumor regions should be sampled to detect mutations in PBRM1, SETD2, BAP1, and/or KDM5C with 90% certainty. The mutational burden of renal tumors varies by region sampled. Single site assessment of key tumor suppressor mutations in primary ccRCC may not adequately capture the genetic predictors of tumor behavior.