ORIGINAL RESEARCH/ CBD available at https://www.cannapyhealth.com/

published: 23 July 2019
doi: 10.3389/fonc.2019.00660
Frontiers in Oncology | www.frontiersin.org 1 July 2019 | Volume 9 | Article 660
Edited by:
Paul N. Span,
Radboud University Nijmegen Medical
Centre, Netherlands
Reviewed by:
James William Jacobberger,
Case Western Reserve University,
United States
Hyuk-Jin Cha,
Seoul National University, South Korea
*Correspondence:
Wilfred Ngwa
wngwa@lroc.harvard.edu
Specialty section:
This article was submitted to
Radiation Oncology,
a section of the journal
Frontiers in Oncology
Received: 28 March 2019
Accepted: 05 July 2019
Published: 23 July 2019
Citation:
Moreau M, Ibeh U, Decosmo K, Bih N,
Yasmin-Karim S, Toyang N, Lowe H
and Ngwa W (2019) Flavonoid
Derivative of Cannabis Demonstrates
Therapeutic Potential in Preclinical
Models of Metastatic Pancreatic
Cancer. Front. Oncol. 9:660.
doi: 10.3389/fonc.2019.00660
Flavonoid Derivative of Cannabis
Demonstrates Therapeutic Potential
in Preclinical Models of Metastatic
Pancreatic Cancer
Michele Moreau1,2, Udoka Ibeh1,3, Kaylie Decosmo1,4, Noella Bih1, Sayeda Yasmin-Karim1,
Ngeh Toyang5, Henry Lowe5 and Wilfred Ngwa1,2*
1 Brigham and Women’s Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, United States,
2 Department of Physics, University of Massachusetts Lowell, Lowell, MA, United States, 3 Department of Biology, University
of Massachusetts Boston, Boston, MA, United States, 4 Department of CaNCURE Program, Northeastern University, Boston,
MA, United States, 5 Flavocure Biotech Inc., Baltimore, MD, United States
Pancreatic cancer is particularly refractory to modern therapies, with a 5-year survival
rate for patients at a dismal 8%. One of the significant barriers to effective treatment
is the immunosuppressive pancreatic tumor microenvironment and development
of resistance to treatment. New treatment options to increase both the survival
and quality of life of patients are urgently needed. This study reports on a new
non-cannabinoid, non-psychoactive derivative of cannabis, termed FBL-03G, with
the potential to treat pancreatic cancer. In vitro results show major increase in
apoptosis and consequential decrease in survival for two pancreatic cancer models-
Panc-02 and KPC pancreatic cancer cells treated with varying concentrations of
FBL-03G and radiotherapy. Meanwhile, in vivo results demonstrate therapeutic efficacy
in delaying both local and metastatic tumor progression in animal models with
pancreatic cancer when using FBL-03G sustainably delivered from smart radiotherapy
biomaterials. Repeated experiments also showed significant (P < 0.0001) increase in
survival for animals with pancreatic cancer compared to control cohorts. The findings
demonstrate the potential for this new cannabis derivative in the treatment of both
localized and advanced pancreatic cancer, providing impetus for further studies toward
clinical translation.
Keywords: pancreatic cancer, flavonoids, cannabis, metastasis, radiotherapy, smart biomaterials
INTRODUCTION
Pancreatic ductal adenocarcinoma is an antagonistic internecine ailment of the exocrine pancreas
with < 8% of patients surviving within a 5-year period (1, 2). A major challenge shared by
pancreatic cancers is its aggressiveness, which often metastasizes to other organs before the patient
is even diagnosed (3, 4).
Current treatment options for pancreatic cancer include: surgery, chemotherapy, targeted
therapy, immunotherapy, and radiation therapy. Curative treatment is available only if the tumor
is found early and can be removed by surgery before metastasis. If the cancer has metastasized,
the standard of care is chemotherapy, or radiotherapy. However, pancreatic cancer is notoriously
defiant to current therapies including chemotherapy, radiotherapy and immunotherapy (1, 5).
Moreau et al. Therapeutic Potential of Flavocure in Pancreatic Cancer
Cannabinoids, which are the bioactive components of
Cannabis sativa and their derivatives, have been investigated
as both anti-cancer agents and for managing the side effects
of conventional cancer treatments like chemotherapy and
radiotherapy (6). Previous studies have indicated that medical
cannabis derivatives could enhance survival in pancreatic cancer
animal models, when used in synergy with radiotherapy (7).
Smart materials for drug delivery like the smart radiotherapy
biomaterials (SRBs) system have also been investigated for
delivering cannabinoids into tumors to enhance radiotherapy
treatment for pancreatic cancer (8). A major benefit of the SRB
approach is their ability to be employed in place of currently used
inert radiotherapy biomaterials (e.g., spacers, or fiducialmarkers)
and hence their use could come at no additional inconvenience
to patients.
In this study, we investigate a new non-cannabinoid, nonpsychoactive
derivative of cannabis, called FBL-03G, to assess its
potential for the treatment of pancreatic cancer. We hypothesize
that the use of FBL-03G will have therapeutic potential and can
enhance radiotherapy during the treatment of pancreatic cancer.
To investigate this hypothesis, in vitro studies were first carried
out with and without radiotherapy (RT). In vitro studies, in vivo
studies were also conducted in small animals employing FBL-
03G sustainably delivered from smart radiotherapy biomaterials,
allowing continual exposure of the tumor to the cannabis
derivative payloads over time.
Apart from the antineoplastic properties of cannabis
derivatives, the immune system modulative properties of
these extracts have been well documented (8–12). Different
volumes and concentrations of FBL-03G payloads were also
investigated for their potential to generate systemic tumor
responses. In particular, we investigated the abscopal effect,
whereby radiotherapy (RT) at one site may lead to regression
of metastatic cancer at distant sites that are not irradiated (13).
The abscopal effect has been connected to mechanisms involving
the immune system (14). However, the abscopal effect is rare
because at the time of treatment, established immune-tolerance
mechanisms may hamper the development of sufficiently robust
abscopal responses. Today, the growing consensus is that
combining radiotherapy with immunoadjuvants provides an
opportunity to boost abscopal response rates, extending the use
of radiotherapy to treatment of both local and metastatic disease
(15). With in this context, the cannabis derivative FBL-03G was
also investigated as a potential immunoadjuvant to radiotherapy.
MATERIALS AND METHODS
Materials and Antibody
Acetone, Dimethyl sulfoxide (DMSO), Poly (lactic-co-glycolic)
acid (PLGA) (M.W.: 50–50 kDa), and Crystal Violet dye were
acquired from Sigma-Aldrich. The Harvard apparatus was
obtained from Harvard Bioscience (Holliston, MA, USA), and
silicone tubing (ID 1/32
′′
) was purchased from Saint-Gobain
Performance Plastics Laboratory Division (USA). Brachytherapy
needles were purchased from IZI Medical Products (MD,
USA). All cell culture products (DMEM, RPMI, Trypsin,
Fetal Bovine Serum, MEM non-essential amino acids, sodium
pyruvate, b-mercaptoethanol, penicillin/streptomycin, and PBS
pH 7.4) were obtained from Gibco, Thermo Fisher, and Life
Technologies (Waltham, MA, USA). Flavocure Biotech Inc.
(Baltimore, MD, USA) supplied the test molecule, FBL-03G
with a purity of 98.7% determined by High Performance Liquid
Chromatography (HPLC).
FBL-03G Synthesis
FBL-03G, a flavonoid derived from Cannabis sativa L., is the
unnatural isomer of Cannflavin B, a metabolite of Cannabis.
Through a bioactivity guided isolation approach, 11 flavonoids
were isolated using flash chromatography and characterized by
nuclearmagnetic resonance (NMR) andmass spectrometry (MS)
methods (2, 16, 17). Generated spectroscopic data for FBL-03G
were similar to those of the following 11 previously isolated
and characterized compounds of the Cannabis plant; apigenin
(1), Chrysoeriol (2), kaempferol (3), luteolin (4), quercetin (5),
vitexin (6), isovitexin (7), orientin (8) and prenylated flavonoids
including Cannflavin A (9), Cannflavin B (10) and Cannflavin C
(11) (Figure S1) (16–21). The molecules were further screened
for kinase inhibition, and chrysoeriol (Cresorol) demonstrated
significant activity against FLT3, FLT3-ITD, and FLT3-D835Y
andmoderate activity against CSF1R (2). FBL-03G demonstrated
significant activity against CSF1R kinase and moderate activity
against FLT3, FLT3-ITD, FLT3-D835Y, CK2a, CK2a2, Aurora A,
Aurora B, Aurora C, and Pim2 (2).
Fabrication of Smart Radiotherapy
Biomaterials (SRB)
This study used combination treatment of FBL-03G (Mw =
368.38 g/mol) as an immunoadjuvant, delivered from smart
radiotherapy biomaterial (SRB), and radiotherapy (RT). SRBs
were developed following previously reported procedures for
fabricating and loading drugs into SRBs. Briefly, 300mg of Poly
(lactic-co-glycolic) acid (PLGA) polymer added to 3.5mL of
acetone was homogenously mixed into a hydrogel (8, 22). The
Harvard apparatus was used to provide a constant flow rate of
the mixture into the silicon tubing with inner diameter of 1/32

.
The PLGA hydrogel loaded in silicon tubing was allowed to cure
under 50◦C for 48 h. After curing, the silicon tubing was cut
to 5mm length and the SRBs were extracted. Three different
concentrations of FBL-03G, respectively, were used as payloads
in the SRBs. A small animal radiation research platform (SARRP,
Xtrahl, Inc., Suwanee, GA, USA) was used for radiotherapy using
220 kVp, 13mA, (10 × 10) mm nozzle, and 0.15mm copper
(Cu) filter to deliver 6 gray (Gy) dose. In addition, computed
tomography (CT) images of the mice were taken using at 65-kVp
and 0.8-mA. Mice were anesthetized with isoflurane and imageguided
radiotherapy was used to specifically irradiate tumors on
one site as needed.
Cell Culture
Pancreatic cancer cell line, Panc-02, was obtained from
the National Cancer Institute and cultured with Dulbecco’s
Modified Eagle’s Medium (DMEM) with 10% FBS and 1%
penicillin/streptomycin. Another pancreatic cancer cell line,
Ptf1/p48-Cre (KPC) cells were a gift from Dr. Anirban Maitra
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Moreau et al. Therapeutic Potential of Flavocure in Pancreatic Cancer
(MDAnderson Cancer center). KPC cell line was derived froman
LSL-Kras; p53+/floxed, Pdx-cre mouse. KPC cells were cultured
in RPMI media supplemented with 10% FBS, 2 mmol/L Lglutamine,
1% penicillin/streptomycin, 1% MEM non-essential
amino acids, 1 mmol/L sodium pyruvate, and 0.1 mmol/L b-
mercaptoethanol. All cells were cultured at 37◦C in a humidified
incubator with 5% CO2.
Clonogenic Survival Assay
Actively growing monolayers of KPC and Panc-02 cancer cells
were trypsinized and 300 cells per well were seeded in 6-well
plates. 24 hours later, seeded cells were treated with 0, 1, 2,
or 4μM of FBL-03G concentrations per well. The cells were
irradiated at 0, 2, or 4Gy using 220 kVp energy, 13mA, 24 h
after the FBL-03G treatment. A small animal radiation research
platform (SARRP) was used to deliver external beam radiation.
The growing colonies (≥ 50 cells/colony) were fixed with 75%
ethanol and stained with 1% crystal violet 9–12 days after
treatment. Colonies were counted using ImageJ software and a
percent survival was calculated following standard protocol.
Mice and Generation of Syngeneic
Pancreatic Cancer Models
Wild-type C57BL/6 strain male and female mice were acquired
from Taconic Biosciences, Inc. at 8-weeks old. Animal
experiments followed the guidelines and regulations set by
the Dana-Farber Cancer Institute Institutional Animal Care
and Use Committee (IACUC). Mice maintenance in Dana-
Farber Cancer Institute animal facility was in accordance with
the Institutional Animal Care and Use Committee approved
guidelines. All treatments were given directly to one tumor
either by direct intra-tumoral injection or by intra-tumoral
implantation of loaded SRB for sustain release. For cohorts
treated in conjunction with radiotherapy, a Small Animal
Radiation Research platform (SARRP) was used for imageguided
radiation therapy at 220 kVp and 13mA. The study
design included a randomization process of the mice followed
by assortment into the following cohorts of: no treatment, RT
dose of 6Gy, FBL-03G with/without 6Gy, and SRB loaded with
FBL- 03G and with/without 6Gy. All mice that received FBL-03G
treatment in the first and second trials were treated with 100-μg
of FBL-03G immunoadjuvant. The same amount of payload
was used in SRBs as with other administration routes. SRBs
were administered in the right tumors using a 17-Gauge clinical
brachytherapy needle. Dimethyl sulfoxide (DMSO) was used as a
solvent to dissolve FBL-03G powder. To investigate the potential
of FBL-03G as an immunotherapy, different concentrations for
FBL-03G in the amount of 100, 200, and 300 μg were considered.
Same procedure of drug loading into SRBs were followed as
the first and second trials. Tumor volumes were measured for
both tumors on day of treatment and at least 1–2 times/week
post-treatment. A survival study was also performed. Mice were
euthanized when either tumor exceeded 20mm in diameter
collectively and/or when tumors were ulcerated or ruptured. A
control cohort was created with no treatment of FBL-03G but an
inoculation of DMSO.
In 3 independent animal studies, the mice were randomized
and divided into some the following cohorts of: no treatment,
6Gy, FBL-03G with/without 6Gy, and SRB loaded with/without
FBL-03G and with/without 6Gy. Mice inoculated with FBL-03G
FIGURE 1 | Illustration of pancreatic therapy approach using non-cannabinoid cannabis derivative, FBL-03G. (A) Currently used commercially-available inert
radiotherapy biomaterials e.g., fiducial (CIVCO Medical)/beacons used during radiotherapy to ensure geometric accuracy (B) smart radiotherapy biomaterials (SRB)
with FDA approved polymer component loaded with FBL-03G; (C) potential clinical translation pathway is envisioned where the SRBs could simply replace the inert
biomaterials (in A). Such replacement would come at no additional inconvenience to cancer patients. Once in place the SRBs can be activated by tumor
microenvironment to sustainably release FLB-03G as the polymer component degrades for greater effective tumor cell kill, potentially with or without radiotherapy.
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Moreau et al. Therapeutic Potential of Flavocure in Pancreatic Cancer
treatment received either 100, 200, or 300 ug of FBL-03G. Payload
of the same amount of FBL-03G was used in SRBs as with other
administration routes.
Tumor Volume Assessment
Directly after treatment, a digital Vernier caliper was used
to measure the length and width of the dermal tumors.
Tumor volume formula used: (length × width2)/2. Measurement
imaginary longitude to the leg was chosen as length and the
vertical was for width. The tumors were restrained between the
skin surface layers. The tumor volume was plotted against time.
Animal survival was performed for treatments following IACUCapproved
protocol, which was predetermined based on published
evidence justifying such a study design. Tumor attainment >
1 cm in diameter on both flanks or tumor burst were determined
as excessive tumor burden and mouse was euthanized following
the protocol.
Statistical Analysis
The in-vitro experiments were conducted in triplicate, and data
were presented as mean ± standard error or in the form
quantified otherwise. Mice tumor volume were scrutinized using
FIGURE 2 | In-vitro anti-cancer effect of FBL-03G. FBL-03G drug from flavonoids shows anti-cell proliferation effects in combination with radiotherapy. Average
results of normalized clonogenic assays are shown, respectively, for Panc-02 and KPC cells. (A,B) Results of synergistic outcomes when combining radiotherapy at
4Gy with different FBL-03G doses. Statistics is shown for cohorts treated at 4Gy at different doses of FBL-03G. Statistical Analyses using Student’s T-Test for the Cell
% survival at different concentrations of FBL-03G graphs (n = 3 independent trials), (*P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001).
FIGURE 3 | Schematic diagram showing the treatment design with radiotherapy and/or intra-tumor injection of FBL-03G/SRB_FBL-03G for subcutaneously
inoculated pancreatic adenocarcinoma tumors. Week 1 represents the treatment week as depicted above after pancreatic cancer (KPC) tumor reached 3.5–4mm in
diameter. The treatment parameters included a single fraction of 6Gy dose of radiotherapy followed by either an inoculation of flavocure drug (FBL-03G) or an implant
of smart radiotherapy biomaterials loaded with similar concentration of the drug, FBL-03G. Tumor volume and mice survival were assessed for up to 7-weeks
post treatment.
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Moreau et al. Therapeutic Potential of Flavocure in Pancreatic Cancer
FIGURE 4 | In-vivo treatment of C57BL/6 mice inoculated with pancreatic cancer cells, KPC, on both flanks. The abscopal effect was examined by monitoring the
non-treated tumor because of the effect of the drug on the treated tumor. Smart radiotherapy biomaterials (SRB) loaded with FBL-03G (100 μg) significantly boosts
the abscopal effect in pancreatic cancer slowing down tumor growth for both treated and untreated tumors. Two experiments were conducted simultaneously: study
1 results are shown in graphs A–E) and study 2 results are displayed in 4(F). (A) Volumes of non-treated tumors over time without SRB (n = 3 for each cohort).
(B) Volumes of treated tumors over time (n = 3 for each cohort). (C) Volume of non-treated tumors over time with SRB and FBL-03G (n = 3 for control and 6Gy
cohorts respectively; n = 4 for SRB loaded with FBL-03G with/without radiotherapy cohorts respectively). (D) Volume of treated tumors over time for cohorts treated
with SRB and FBL-03G (n = 3 for control and 6Gy cohorts respectively; n = 4 for SRB loaded with FBL-03G with/without radiotherapy cohorts respectively). (E,F)
Survival results show significant increase in survival for cohorts treated with SRB loaded with FBL-03G. (E) (n = 3 for each cohort: control, 6Gy, FBL-03G, and
FBL-03G_6Gy; n = 4 for each cohort: SRB_FBL-03G and SRB_FBL-03G_6Gy), (F) (n = 3 for control, n = 5 for each cohort: SRB_FBL-03G and SRB_FBL-03G_6Gy).
Statistical Analyses using Student’s T-Test for the volume vs. time graphs. Log-rank (Mantel-Cox) survival graph (n = 10) (*P < 0.05; **P < 0.01; ****P < 0.0001).
standard Student’s two-tailed t-test. Mice survival were analyzed
using GraphPad Prism 8.0. A p-value of ∗P < 0.05, ∗∗P < 0.01,
∗∗∗P < 0.001, and ∗∗∗∗P < 0.0001 were deemed as statistically
significant difference.
RESULTS
Figure 1 illustrates the therapy approach using FBL-03G loaded
in smart radiotherapy biomaterials (SRBs) for sustained delivery
to tumor cells. Before in-vivo studies with the FBL-03G, in-vitro
studies were carried out with sustained exposure of cancer cells
with FBL-03G. Clonogenic assay was performed to identify
the anti-cancer effect of the FBL-03G drug with and without
radiotherapy on 2 pancreatic cancer cell lines, KPC and Panc-
02. Figure 2 highlights enhanced tumor cell death for the
combination treatment of FBL-03G and radiation compared
to individual treatments alone. The clonogenic survival results
show that the use of 1μM of FBL-03G has synergistic effect
on pancreatic cells with exposure to 4Gy of radiotherapy in
terms of decreasing pancreatic cancer cell proliferation. These
findings were observed for both Panc-02 and KPC pancreatic
cancer cell lines. This demonstrates therapy potential for the
FBL-03G. Moreover, the use of 4μM of FBL-03G was apparently
more effective in killing pancreatic cancer cells than 4Gy of
radiotherapy. This suggests that FBL-03G can induce apoptosis
and inhibit cancer cell proliferation with optimized drug
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Moreau et al. Therapeutic Potential of Flavocure in Pancreatic Cancer
concentrations. The FBL-03G effect on cancer cells combined
with DNA damage from radiotherapy could account for the
observed synergistic outcomes.
Using smart radiotherapy biomaterials for prolonged delivery
of FBL-03G into tumors can also boost malignant cell death
in-vivo with FBL-03G. The in-vivo study design is illustrated
in Figure 3. The results are shown in Figure 4. Figures 4A–D
shows a distinction between direct intra-tumor injection of FBL-
03G vs. using the same concentration of FBL-03G with the
smart radiotherapy biomaterial platform. Figures 4C,D shows
reduction of tumor growth in animal cohorts treated with
FBL-03G loaded in SRB compared to cohorts treated with
direct administration of the same dose of FBL-03G shown in
Figures 4A,B vs. control and irradiated cohorts. Remarkably, the
results in Figure 4D revealed that nearby non-treated (abscopal)
tumors, representing metastasis, were also significantly affected
with slowed tumor growth. Repeated experiments showed
significant increase in mice survival (Figures 4E,F) compared
to control cohorts. The findings provide a basis for further
studies to optimize different parameters for maximal outcomes
via this approach.
In another study we evaluated the effect of FBL-03G using
3 different concentrations (100, 200, and 300 ug) loaded in
smart radiotherapy biomaterials with/without radiotherapy. The
findings in Figure 5 show no significant difference in tumor
volume between using smart radiotherapy biomaterials with
FBL-03G alone vs. using SRBs with FBL-03G payloads in
combination with radiotherapy. However, a significant difference
between 6Gy and control cohorts vs. combination of FBL-
03G in SRB treated groups is observed in Figures 5A,B, where
tumor growth of both treated and non-treated tumors is
inhibited compared to control and 6Gy cohorts. Overall, the data
demonstrates significant therapeutic potential for using FBL-03G
in the treatment of both local andmetastatic disease, significantly
increasing survival (Figure 5C).
DISCUSSION
From the results of this study, the key findings include,
observation that a non-cannabinoid derivative of cannabis can
enhance radiotherapy treatment outcomes in-vitro and in-vivo
as highlighted in Figures 2, 4. Secondly, the sustained delivery
of the cannabis derivative FBL-03G from smart radiotherapy
biomaterials (SRBs) results in tumor growth inhibition of both
locally treated and distant untreated tumors, with and without
radiotherapy. The use of smart radiotherapy biomaterials (SRBs)
(8, 23) was recently proposed as a novel approach to deliver
cannabinoids, allowing for prolonged exposure of tumor cells to
these cannabis derivatives, which is expected to be more effective
(10). The FBL-03G payload used in this study is a flavonoid noncannabinoid
derivative of cannabis, and the potential to inhibit
both local and metastatic tumor progression is remarkable,
especially for pancreatic cancer, with a dismal 5-year survival rate
of 8% (1).
While ongoing studies are in progress to address the specific
mechanism for this immunotherapy potential of this cannabis
derivative, the possibility of leveraging such a therapy approach
to treat metastasis or increase survival is significant, given
FIGURE 5 | Investigating the optimal concentration of FBL-03G loaded in SRB
to enhance the abscopal effect. Smart radiotherapy biomaterial (SRB) loaded,
respectively, with FBL-03G (100, 200, or 300 μg). C57BL/6 mice were
inoculated with pancreatic cancer cells (KPC) on both flanks. Tumor volume
and survival (n = 10 for each cohort) were assessed. (A) Volumes of
non-treated tumors 2-weeks post treatment (n = 10 for each cohort);
(B) volumes of treated tumors 2-weeks post treatment (n = 10 for each
cohort). This study investigated using different concentrations of FBL-03G
with/without 6Gy to determine its potential effect on mice survival over time.
(C) Represents a Log-rank (Mantel-Cox) survival graph (n = 10) (****p <
0.0001). (C) Survival results show no difference in survival for cohorts treated
with different concentrations of SRB loaded with FBL-03G.
that most pancreatic cancer patients are diagnosed already
with metastatic disease, with limited treatment options. The
results highlight the potential of using non-cannabinoid/nonpsychoactive
derivatives of cannabis for such treatment. Further
work to optimize therapeutic efficacy for such cannabis
derivatives and evaluate toxicity could set the stage for clinical
translation. An advantage of the SRB approach here is also that
this could minimize any toxicity due to in-situ delivery and use
of multifold less immunoadjuvant. Furthermore, the use of a
single dose of RT as done in this project would minimize normal
tissue toxicity.
Although Figure 4 shows no significant difference between
using SRBs alone vs. SRBs with RT, SRBs could simply be
used like fiducial markers (23) (Figure 1) offering a viable
pathway to clinical translation at no additional inconvenience to
patients. Another advantage of using SRBs for sustained in-situ
delivery of payloads is the relative convenience in delivering the
immunoadjuvants, compared to repeated injections. Using only
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Moreau et al. Therapeutic Potential of Flavocure in Pancreatic Cancer
one fraction of RT would also be more convenient for cancer
patients who usually must come in repeatedly over many weeks
to be treated with several fractions of radiotherapy. This should
significantly reduce treatment time and costs. It would be a
benefit in resource-poor-settings where access to RT services is
limited, reducing cancer health disparities, with major impact in
global health.
While the results indicate that sustained exposure of tumor
cells to FBL-03G can boost both local and metastatic tumor
cell kill, the mechanism of such action needs to be further
investigated. One hypothesis is that, FBL-03G can serve as an
immunotherapy agent, inhibiting growth of locally treated and
untreated tumors, representing metastasis. Metastasis accounts
for most of all cancer associated suffering and death, and
questionably presents the most daunting challenge in cancer
management. Henceforth, the observed significant increase in
survival is promising, especially for pancreatic cancer which
is often recalcitrant to treatments. Another hypothesis is that
sustained delivery allows FBL-03G to reach the untreated tumor
over a prolonged period as well. Either way, the FBL-03G results
reveal a new potential non-cannabinoid cannabis derivative with
major potential for consideration in further investigations in the
treatment of pancreatic cancer, where new therapy options are
urgently needed.
CONCLUSION
In this study, a flavonoid derivative of cannabis
demonstrates significant therapy potential in the treatment
of pancreatic cancer, including radio-sensitizing and
cancer metastasis treatment potential. The results justify
further studies to optimize therapy outcomes toward
clinical translation.
DATA AVAILABILITY
All datasets generated for this study are included in the
manuscript and/or the Supplementary Files.
ETHICS STATEMENT
Animal experiments and protocol followed the guidelines and
regulations set by the Dana-Farber Cancer Institute Institutional
Animal Care andUse Committee (IACUC). Micemaintenance in
Dana Farber Cancer Institute animal facility was in accordance
with the Institutional Animal Care and Use Committee
approved guidelines.
AUTHOR CONTRIBUTIONS
MMprovided intellectual contributions to the design of the mice
study, generated all the results in this study, designed the smart
radiotherapy biomaterial (SRB) to implant in mice, and wrote
most of the manuscript. SY-K reviewed the manuscript. UI, KD,
and NB helped in tumor measurements for mice and reviewed
the manuscript. NT and HL provided the FBL-03G drug,
contributed to study design, made input in manuscript including
reviewing the manuscript. WN is the principal investigator who
designed the study and wrote a portion of the manuscript.
FUNDING
Funding support for this work is acknowledged from the USA
National Institutes ofHealth (NIH), grant number R21CA205094
and Flavocure Biotech Inc.
ACKNOWLEDGMENTS
We thank all the members at Ngwa’s lab at Dana Farber Cancer
Institute and Harvard Medical School, Boston, Massachusetts
for their support, and Servicebio Inc., Woburn, Massachusetts
for technical support. Bio-Tech R&D Institute, University of
the West Indies, Mona, Jamaica is also acknowledged for its
technical support.
SUPPLEMENTARY MATERIAL
The Supplementary Material for this article can be found
online at: https://www.frontiersin.org/articles/10.3389/fonc.
2019.00660/full#supplementary-material
Figure S1 | Structures of Cannabis flavonoids and the unnatural molecule
FBL-03G. Through a bioactivity guided isolation approach, Cannflavin B (10) was
isolated from a flavonoid rich fraction of Cannabis using flash chromatography
along with 10 other compounds and characterized by NMR and MS
spectroscopic methods. The spectroscopic data were similar to the data of the
following 11 compounds previously isolated and characterized from the Cannabis
plant; apigenin (1), Chrysoeriol (2), kaempferol (3), luteolin (4), quercetin (5), vitexin
(6), isovitexin (7), orientin (8) and prenylated flavonoids including Cannflavin A (9),
Cannflavin B (10), and Cannflavin C (11).
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Conflict of Interest Statement: NT and HL work for Flavocure Biotech Inc., a
for-profit company.
The remaining authors declare that the research was conducted in the absence of
any commercial or financial relationships that could be construed as a potential
conflict of interest.
Copyright © 2019 Moreau, Ibeh, Decosmo, Bih, Yasmin-Karim, Toyang, Lowe and
Ngwa. This is an open-access article distributed under the terms of the Creative
Commons Attribution License (CC BY). The use, distribution or reproduction in
other forums is permitted, provided the original author(s) and the copyright owner(s)
are credited and that the original publication in this journal is cited, in accordance
with accepted academic practice. No use, distribution or reproduction is permitted
which does not comply with these terms.
Frontiers in Oncology | www.frontiersin.org 8 July 2019 | Volume 9 | Article 660