Incorporating blood-based liquid biopsy information into cancer staging: time for a TNMB system?

Tissue biopsy is the standard diagnostic procedure for cancer. Biopsy may also provide material for genotyping, which can assist in the diagnosis and selection of targeted therapies but may fall short in cases of inadequate sampling, particularly from highly heterogeneous tumors. Traditional tissue biopsy suffers greater limitations in its prognostic capability over the course of disease, most obviously as an invasive procedure with potential complications, but also with respect to probable tumor clonal evolution and metastasis over time from initial biopsy evaluation. Recent work highlights circulating tumor DNA (ctDNA) present in the blood as a supplemental, or perhaps an alternative, source of DNA to identify the clinically relevant cancer mutational landscape. Indeed, this noninvasive approach may facilitate repeated monitoring of disease progression and treatment response, serving as a means to guide targeted therapies based on detected actionable mutations in patients with advanced or metastatic solid tumors. Notably, ctDNA is heralding a revolution in the range of genomic profiling and molecular mechanisms to be utilized in the battle against cancer. This review will discuss the biology of ctDNA, current methods of detection and potential applications of this information in tumor diagnosis, treatment, and disease prognosis. Conventional classification of tumors to describe cancer stage follow the TNM notation system, heavily weighting local tumor extent (T), lymph node invasion (N), and detectable metastasis (M). With recent advancements in genomics and bioinformatics, it is conceivable that routine analysis of ctDNA from liquid biopsy (B) may make cancer diagnosis, treatment, and prognosis more accurate for individual patients. We put forward the futuristic concept of TNMB tumor classification, opening a new horizon for precision medicine with the hope of creating better outcomes for cancer patients.

Abstract P3-01-04: Obesity induces functional transcriptomic changes enhancing the cancer hallmarks of estrogen receptor-positive breast cancer

Obesity increases the risk of cancer death among postmenopausal women with estrogen receptor-positive (ER+) breast cancer, but the direct evidence for the mechanisms is lacking. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating this epidemiologic phenomenon. Transcriptomic profiles of pretreatment biopsies from a prospective cohort of 137 ER+ breast cancer patients were analyzed. A transgenic and an orthotopic/syngeneic obese mouse models were created to phenocopy obese patients and evaluate the effect of obesity on breast carcinogenesis and tumor progression, and to explore further direct mechanisms. Functional transcriptomic analysis of untreated human ER+ breast cancer revealed that obesity was associated with increased insulin signaling among others. Many of the functional changes in obese patients were linked to cancer hallmarks. Obese mouse models recapitulated the functional transcriptomic landscape of obesity-associated changes seen in human ER+ breast cancer and demonstrated the role of the Akt/mTOR pathway in obesity-induced breast carcinogenesis and tumor progression. Functional transcriptomic analysis identified 85 biological functions common to humans and mice. An in vitro co-culture model revealed that adipocyte-secreted adipokines (e.g., TIMP-1) regulate adipocyte-induced breast cancer cell proliferation and invasion. The human transcriptomic data provided direct evidence for the roles of hyperinsulinemia, estrogen signaling, adipokine secretion, and inflammation in the link between obesity and ER+ breast cancer. Our animal experiments provide strong evidence for the causal relationship between obesity and accelerated carcinogenesis and cancer progression and for potential therapeutic interventions by blocking these signaling pathways.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-01-04.

Apoptosis-dependent and -independent mechanisms mediate the phagocytic recognition/clearance of the HL60-A1 transfectants with prolonged survival

OBJECTIVE

The phagocytic recognition and clearance of the recruited inflammatory cells with prolonged survival play a pivotal role in relieving tissue inflammation and maintaining tissue homeostasis. Transgenic mice expressing Bcl-2 in mature neutrophils demonstrated that Bcl-2 attenuated neutrophil apoptosis, while the homeostasis of the neutrophil population was essentially unaffected. This result suggests that clearance of neutrophils with prolonged survival operates independently from apoptosis. Owing to the constitutive and inducible expression of Bcl-2 homologue, A1 in human neutrophils and the intolerance of preparation for the isolated human neutrophils with prolonged survival, the human promyelocytic HL60-A1 transfectants were established to study the mechanism of phagocytic recognition/clearance of the cells with prolonged survival.

MATERIALS AND METHODS

The non-apoptotic cells with prolonged survival were enriched by serum withdrawal for five days and negatively isolated by annexin V-binding beads. Then, the cells were labeled with a fluorogenic marker. Monocyte-derived macrophages (MDM) were co-cultured to perform the phagocytosis assay, and flow cytometry was employed to determine the phagocytic index.

RESULTS

In the serum-free condition, the phagocytic index of HL60-A1 transfectants was little different from that of the HL60-EGFP control, despite showing a significantly lower degree of apoptosis. While the phagocytic index of HL60-EGFP control was significantly correlated with the degree of apoptosis, the index of the HL60-A1 transfectants was less relevant to it. The phagocytic index for the annexin V-positive cells did not distinguish the two cell types. However, the phagocytic index for the annexin V-negative cells from the HL60-A1 transfectants was increased with age in days. Preincubation of MDM with the scavenger receptor inhibitor, Oxi-LDL, and the inhibitory antibodies against alphavbeta3, CD14 and CD36 surface molecules could attenuate the phagocytic recognition of the annexin V-positive HL60 cells but not the annexin V-negative A1 transfectants with prolonged survival.

CONCLUSIONS

This study thus suggests that a mechanism unrelated to apoptosis exists, which mediates the phagocytic clearance of the non-apoptotic cells with prolonged survival and may be associated with A1 function in the myeloid cells.

Influences of Follicular Size on Parthenogenetic Activation and in Vitro Heat Shock on the Cytoskeleton in Cattle Oocytes

The availability of cow ovaries from the slaughterhouse has been very limited in Taiwan. To maximize the use of cow ovaries for research purposes, whole ovary dissection was performed and the developmental competence of the oocytes derived from different sizes of follicles was assessed by the rates of in vitro maturation (IVM) and parthenogenetic activation of the oocytes in Experiment 1 (Exp 1). Cumulus-oocyte complexes (COCs) derived from small (1-2 mm) and large (3-8 mm) follicles were subjected to standard IVM culture for 24 h. Mature oocytes were selected and then parthenogenetically activated using A23187 (5 microm, 5 min) or thimerosal (200 microm, 10 min) alone or combined with 6-dimethylaminopurine (2.5 mm and 3.5 h, respectively). Activation rates of the oocytes, neither from the large nor small follicles, were affected by different activation treatments (single or combined stimuli). Whereas maturation rates for the oocytes from large follicles were superior to those from small follicles in both the single (59% vs 45%) and combined treatments (76% vs 40%; p < 0.05). To understand how prolonged heat shock (HS) influences cytoskeletal configurations of mature bovine oocytes, in Experiment 2 (Exp 2), matured oocytes derived from large follicles were randomly allocated to different durations of HS treatments at 41.5 degrees C for 0 (C0h, control, n = 12), 1 (HS1h, n = 28), 2 (HS2h, n = 31), and 4 h (HS4h, n = 30). An additional control group was cultured for 4 h without HS (38.5 degrees C, 4 h, n = 35). Alterations in nuclear structures, microtubules (MTs), and microfilaments (MFs) of the oocytes were examined. Abnormalities in the chromosomes, spindle MTs and the percentages of oocytes with cytoplasmic MTs increased with time of HS treatment. The intensity of the MF distribution in the HS oocytes was also altered. Significant changes in the cytoskeleton after HS may be associated with the reduced development under hyperthermia and, perhaps, with the low pregnancy rates of the animals during hot seasons.

Reconfigurable time-domain spectral shaping of an optical pulse stretched by a fiber Bragg grating

We demonstrate a method for spectrally shaping optical pulses that is readily reconfigurable and can produce variable filter functions. This practical technique relies on a compact and robust 3.86-m-long linearly chirped fiber Bragg grating that chromatically disperses the pulse to ~30 ns. We then shape the pulse envelope, and thus the pulse spectrum, with a programmable arbitrary waveform generator and an amplitude modulator to obtain several filter functions.

Study of human forearm posture maintenance with a physiologically based robotic arm and spinal level neural controller

The goals of this research are: (1) to apply knowledge of human neuro-musculo-skeletal motion control to a biomechanically designed, neural controlled, 'anthroform' robotic arm system, (2) to demonstrate that such a system is capable of responses that match those of the human arm reasonably well in comparable experiments, and (3) to utilize the anthroform arm system to study some controversial issues and to predict new phenomena of the human motion control system. A physiologically analogous artificial neural network controller and an anatomically accurate robotic testing elbow are applied in this study. In order to build the physical elbow system to have mechanical properties as close as possible to the human arm, McKibben pneumatic artificial muscles, force sensors, and mechanical muscle spindles are integrated in the system with anatomically accurate muscle attachment points. A physiologically analogous, artificial neural network controller is used to emulate the behavior of spinal segmental reflex circuitry including Ia and Ib afferent feedbacks. Systematic experiments of elbow posture maintenance are performed and compared with physiological experimental data. New experiments are performed in which responses to torque perturbation are measured when selected afferent pathways are blocked. A 'covariance diagram' is introduced. And a linear model is used to help to analyze the roles of system components. The results show that muscle co-contraction and Ia afference with gamma dynamic motoneuron excitation are two efficient ways to increase joint stiffness and damping, which in turn reduces the mechanical sensitivity of the joint to external perturbation and shortens the settling time of the system.

Neoadjuvant chemotherapy with cisplatin, vincristine, and bleomycin and radical surgery in early-stage bulky cervical carcinoma

Neoadjuvant chemotherapy consisting of 2-3 courses of cisplatin, vincristine, and bleomycin was used in the primary treatment of 36 consecutive patients with locally advanced early-stage cervical carcinoma [International Federation of Gynecology and Obstetrics (FIGO) stages Ib or IIa; tumor size, greater than or equal to 4 cm]. The effectiveness of the preoperative chemotherapy was evaluated in the surgical specimens. Among the 33 evaluable patients, the overall clinical response rate was 84.8%, which included a complete response in 8 patients (24.2%) and a partial response in 20 subjects (60.6%). No residual tumor was found in the surgical specimens obtained from 2 complete responders. This therapy induced varying degrees of tumor shrinkage and rendered radical surgery feasible in all evaluable cases despite the initial bulky size of the lesions. No significant difference was observed in the response rate according to age and disease stage. Lymph-node metastases were found after chemotherapy in 18.2% (6/33) of the patients. Grade II and III hematological toxicities occurred in 23.3% of the 90 chemotherapy cycles completed. Nausea and vomiting occurred to a mild to moderate degree in 75 (83.3%) cycles. These preliminary results suggest that the administration of induction chemotherapy involving two to three courses of cisplatin, vincristine, and bleomycin prior to surgery is effective in reducing the tumor volume and in providing better circumstances for surgical removal of the early yet bulky cervical tumors and results in tolerable toxicity. This protocol is now undergoing prospective randomized trials to test its impact on long-term survival.